The 
Biology of Man 
Other Organisms 
Henry R. Linvilfe THE BIOLOGY OF MAN 
AND 
OTHER ORGANISMS 
BY 
HENRY R. LINVILLE, Ph.D. 
FORMERLY HEAD OF DEPARTMENT OF BIOLOGY IN THE DEWITT 
CLINTON HIGH SCHOOL AND IN THE JAMAICA HIGH SCHOOL 
NEW YORK CITY; CO-AUTHOR, LINVILLE AND KELLY’S 
TEXTBOOK IN GENERAL ZOOLOGY 
NEW YORK 
HARCOURT, BRACE AND COMPANY COPYRIGHT, 1923, BY 
HARCOURT, BRACE AND COMPANY, INC. 
Printed in the U. S. A. PREFACE 
First of all, this textbook probably covers any formal 
syllabus in biology now in use. But if the book did only that, 
its existence would be inexcusable. At most, the average 
syllabus is a crystallization, a static thing. A syllabus in 
biology is almost a contradiction in terms, because the 
essence of biology is dynamic and fluid life. For this reason, 
a good textbook must transcend the syllabus, and break 
new paths for the minds of the young. The inspiring portion 
of any textbook in biology will continue as something over 
and above the things that are likely to be named in any 
formal outline of topics, subtopics and suggested material. 
There are two groups of critics which teachers of biology, 
and the writers on that subject must encounter. One of 
these groups is composed of young students who have to be 
attracted to undertake serious intellectual work of any kind. 
They may say frankly that they don’t care for biology. The 
other group is composed of grown-ups who regard the sub- 
ject of biology as of slight importance in the intellectual life 
of modern times. Curious and often interesting, they say, 
but more a museum than an interpretation of real life for 
intelligent, red-blooded men and women. 
It would be a valuable experience to teachers of biology if 
they should listen to these groups of critics, or to any others, 
and seek thereby to ascertain the bases of the objections. 
Probably there is no objection to biology itself, but, in the 
case of the adolescents, rather to the forbidding or dis- 
ciplinary aspects of the methods pursued in its presentation. 
The intellectuals are not concerned so much with matters 
of presentation. Their objection is directed against the PREFACE 
biologists themselves. To these critics the biologists do not 
seem to be interested in establishing the fundamental con- 
nections between biology and the great social problems in 
human life. To them there seems to be in the minds of biolo- 
gists too much of “bugs and flowers,” and too little of man- 
kind. In other words, the very devotion of biologists to their 
subject-matter seems to cause them to narrow their vision, 
and to fail to see, and hence to point out, the ramifications 
of the principles and the processes of biology in the living, 
and in the activities, of all human beings. 
This tendency to narrowness on the part of our profes- 
sional biologists results in putting off the day of the possible 
supremacy of biology as a great educational and social science. 
We must get into the stream of human life itself with our 
equipment of biological lore. We must learn the special 
forces manifesting themselves in that stream. We must 
also be ready to assist in directing these forces along clearly 
discernable biological lines, to the end that the greatest 
possible power in the race may be developed. 
The “over and above” part of this book comprises an 
attempt to meet the sound objections of critics of the two 
groups mentioned, and possibly of other groups as well. This 
is done by making biology set its best foot forward. “ Human 
interest ” is a good pedagogical lead. It is not sensationalism. 
Young persons, and older ones, too, like stories that bring 
out the charm of existence, their own existence, or of some 
existence in obvious or suggested relation to theirs. With 
this approach well laid, the mind has no hesitation in setting 
to work to comprehend the intricacies of life itself. If this 
approach can be made better than it is done in this book, 
that is still the thing to do. 
For the rest, the working out of the biological principles 
and processes in their relation to the manifold activities 
in which man engages, and to his origin, his background, his 
environment, and his destiny, serves as the basis upon which PREFACE 
biology may fittingly lay claim to the intelligent considera- 
tion of the human mind. If this working out is well done, 
biology will no longer mean “bugs and flowers.” It will 
mean life, and at the center, comprehending it all, and in 
large measure controlling and directing it, will stand man 
himself. 
The Author. 
June 1, 1923 CONTENTS 
Chapter Page 
I. Introduction 1 
II. The Slipper Animalcule and Its Near Kin.. .. 0 
Amoeba. Foramenifera. The Malarial Para- 
site. The Yellow Fever Parasite. Summary 
of the Protozoa. 
III. Sponges 14 
IV. Jellyfishes and Coral Polyps 10 
Medusae and Hvdroids. Hydra. Giant Jelly- 
fishes. Coral Polyps. Summary of the Coelen- 
tera. 
V. Starfishes and Sea Urchins 23 
T1 ie Starfish. The Sea-Urchin. Summary of 
the Eehinoderma. 
VI. The Earthworm and Its Kindred. 27 
The Earthworm. The Sandworm. The Tape- 
worm. The Hookworm. Summary of the 
“Vermes.” 
VII. Insects and Their Near Relatives 30 
The House-fly. The Mosquito. The Honey- 
bee. Ants. Wasps. Gall-flies. The June- 
bug. The Lady-bug. The Click-beetle. The 
Fire-fly. The Black Swallow-tail Butterfly. 
American Silkworms. The Ant-Lion. Scale- 
bugs. Grasshoppers. Summary of the In- 
secta. The Lobster. Spiders. Centipedes. 
Summary of Arthropoda. 
VIII. Mussels and Tiieir Kin 72 
The Fresh-water Mussel. The Soft-shell clam. 
The Oyster. Snails. The Squid. Summary 
of Mollusca. CONTENTS 
Chapter Page 
IX. The Fishes 81 
The Sunfish. The Eel. Sharks. Codfish. 
The Salmon. Summary of Fishes. 
X. Frogs, Toads, and Salamanders 92 
The Leopard Frog. Toads. The Salamander. 
Summary of Amphibia. 
XI. Snakes and Other Reptiles 102 
The Blacksnake. The Rattlesnake. The Box 
Turtle. The American Chameleon. The Alli- 
gator. Summary of Reptiles. 
XII. Birds 112 
The Ruffed Grouse. The Chicken Hawk. The 
Whip-poor-will. The Crow. The House- 
Wren. The Nuthatch. The Hermit Thrush. 
Summary of Birds. 
XIII. Mammals 123 
The Oppossum. The Right Whale. The 
Prong-horned Antelope. The Chipmunk. 
Bats. The Fur Seal. The Weasel. Summary 
of Mammalia. 
XIV. Animals from the Beginning of Time 138 
The Fabled and the Real. The Vastness of 
Time. Life and the Rocks. Changes in the 
Land and its Inhabitants. Changes in Condi- 
tions and in Species. Howr the New arise and 
the Old disappear. How Life is Classified in 
Time. 
XV. Up from Savagery 154 
Man’s origin in Time. Man’s Relatives. His 
Birthplace and his Migrations. The Old Stone 
Age. The New Stone Age. The Four Races of 
Men. The Continuance of Mutations. The 
Relation of Progress to Food Supply. The 
Up and Down phases in Civilization. The 
Human Brain, the Leader and the Hinderer. CONTENTS 
Chapter Page 
How the World Grows Better. Civilization 
and Education. Better Brains our Great 
Need. Our Crude Beginnings in Mending the 
Race. The New Ideal for the Future. Social 
Control of Inheritance. Social Control over 
Conditions. 
XVI. Domesticated Animals; and Mendel’s Law of 
Heredity 181 
Introduction. The Horse. The Mule. The 
Ox. The Sheep. The Pig. The Dog. The 
Cat. The Chicken. Possible additions to the 
Kinds of Domesticated Animals. Mendelian 
Inheritance in Man. 
XVII. The Environment of Plants and Animals 208 
XVIII. Green Plants 214 
I’leurococcus. Spirogyra. The Rockweed. 
XIX. Non-Green Plants 222 
Bacteria. Yeast. Bread Mold. The Wheat 
Rust. Mushrooms. 
XX. Mosses and Ferns 235 
A Moss. A Fern. 
XXL The Indian Corn 243 
Photosynthesis. Transpiration. Respiration. 
Corn Meal. Samp and Hominy. CornStarch. 
Glucose. Corn Oil. 
XXII. The Bean 250 
XXIII. The Forests 265 
XXIV. Plant Breeding 277 
XXV. The Farm, A Comprehensive Biological Unit 286 
XXVI. Our Resources in Food 297 
Grain Products. Vegetables. Fruits and 
Nuts. Sugars. Fats and Oils. Meats. Milk. 
Eggs. CONTENTS 
Chapter Page 
XXVII. Our Resources in Clothing 317 
Cotton. Linen. Wool. Silk. 
XXVIII. Our Bodies as We Find Them; and the Foods 
They Need 328 
Living and Working. A Wonderful Industry. 
Our Primal Need. The Nutrients. Growing 
and Repairing. The Human Machine. Oxida- 
tion and Energy. 
XXIX. The Sources of Our Food Supply 338 
Natural Foods. Sugars. Starch. Fats. Pro- 
teins. Other Important Sources of Nutrient 
Supply. Vitamins. 
XXX. What to Eat, How Much, and Why 351 
Why Some Grow Old too Early. From Old 
Age to Youth. Eating as a Habit. The Chief 
Bad Habit in Eating. Where to Begin to Re- 
form Easily. Thinking and Planning before 
Eating. The Principles Applied. 
XXXI. Tub Care and the Preparation of Food 361 
Old Prejudices and New Ideas. Experience, 
the Source of New Ideas. The Cold Storage 
System. Chemical Preservatives. Cooking. 
XXXII. Extras 368 
Tea and Coffee. Cocoa and Chocolate. The 
Nefarious Soda Fountain. 
XXXIII. The Organs of Digestion, and Wiiat Goes on 
in Them 371 
The Organs as Parts of a System. Looking 
into One’s own Mouth. Mistreated Teeth. 
Knowing the Reasons. Lurking Places of 
Trouble. “Dental Insurance.” The Teeth at 
Work. The Tongue. The Pharynx. The 
Stomach. The Small Intestine. The Diges- 
tive Glands. Enzymes. The Conditions of 
Digestive Action. From the Stomach to the CONTENTS 
Chapter Page 
Small Intestine. What the Enzymes Do. 
Appendix. The Large Intestine. Absorption. 
XXXIV. The Circulatory System 390 
Your Own Circulatory System under Examina- 
tion. The Operation of the Heart. The 
Meaning of the Circulatory System. The 
Composition of the Blood. The Lymph Sys- 
tem. 
XXXV. The Destination of the Income and the Outgo 
of Living 398 
The Transportation, the Storing, and the Oxi- 
dation of Fowl. End-Products in Digestion. 
The Loss and the Repair of Protein. The Chief 
Sources of Energy. The Structure and Con- 
nections of the Lungs. The Waste Excreted 
by the Lungs. The Structure and Connections 
of the Kidneys. The Structure and the Func- 
tions of the Skin. The Heat-Ad justing Ac- 
tivity. The Hygienic and Moral Values of the 
Warm Bath. Ventilation in Relation to Heat. 
XXXVI. The Nervous System and the Control of Liv- 
ing 409 
The Supremacy of the Human Brain. The 
Parts of the Brain and their Functions. The 
Brain as a Central Station. The Nerve Units 
and their Activities. Reflex Action. The 
Source of our Habits. Why Some Brains are 
Better than Others. Going into Training with 
our Brains. The Will the Master. Nerve 
Activity without the Will. Working under 
the Will. Work and its Enjoyment. Habits 
as Tools for Living. The Independent Mind. 
The Ideals of a Thinking Brain. 
XXXVII. The Sense Organs and Their Care 434 
The Care of the Ears. The Care of the Eves. CONTENTS 
Chapter Page 
XXXVIII. The Bones and the Muscles; and Their Proper 
Care 439 
The Skeleton. The Care of the Skeleton. The 
Muscles. Work and Rest. Athletics. Over- 
weight and Underweight. 
XXXIX. The Builders of Biology 4.50 
Aristotle (384-322 B. C.). Vesalius (1514- 
1565 A. D.). Harvey (1578-1657). Malphigi 
(1628-1694). Linnams (1707-1778). Cuvier 
(1769-1829). Bichat (1771-1801). Muller 
(1801-1858). Schleiden (1804-1881); Schwann 
(1810-1882). Schultze (1825-1874). Virchow 
(1821-1903). Pasteur (1822-1895). Lister 
(1827-1912). Lamarck (1744-1829). Dar- 
win (1809-1882). Agassiz (1807-1873). Hux- 
ley (1825-1895). Weismann (1834-1916). 
Mendel (1822-1884). Gray (1810-1888). 
DeVries (1848 ). Galton (1822-1911). 
Burroughs (1837-1921). 
XL. Things and Conditions that Hold Us Back 479 
A Toppling Monarch. The Drug Menace. 
The Smoking Nuisance. Disease. 
Index 497 THE BIOLOGY OF MAN AND 
OTHER ORGANISMS 
CHAPTER I 
INTRODUCTION 
As little children all of us have annoyed our parents 
greatly by the incessant asking of questions. Alas, too 
many of us have been trained out of that racial habit. But 
happily some have retained it to the great pleasure of 
themselves, and to the good of mankind. For, asking 
questions is the expression of an inner curiosity. And 
curiosity has always been a very important stimulus to the 
making of the great discoveries for which our civilization 
is famous. 
Among the many discoveries that have resulted from the 
habit of expressing our curiosity is the one that shows 
Nature as the original and authentic source of knowledge. 
Nowadays, we may think such a statement is like an axiom, 
a fact that is self-evident, but the history of natural science 
shows that for hundreds of years in the early part of the 
Christian era men preferred to ask what the great Greek 
philosopher, Aristotle, had thought about a subject. It 
seems never to have occurred to the wisest men there were 
in those days that Aristotle himself, or others before him, 
must have gone to Nature for their information. 
Although wre must necessarily obtain our facts from 
Nature, we should understand that we use the expression 
“going to Nature” only in a figurative sense. Nature is 
not a person, and cannot tell us anything. Nature is a mar- 
1 INTRODUCTION 
2 
velously complex system of facts, manifested as living and 
non-living things and as processes. Without the mind of 
man to see, to investigate, and to understand, we might 
almost say Nature does not exist. 
Thus, there is infinite use for our inborn disposition to 
inquire. The use a particular person may make of the trait 
may seem trifling to the young student, doubtful of his 
powers to see and understand, but we have discovered that 
the desire to know, and a confidence in one’s ability to com- 
prehend, come with practice. There are many elder persons 
who interfere with the natural education of a child by do- 
ing things for him. Much of the doubt of our own abilities 
conies from being told as children that we “cannot do it 
right.” What a pity it is to do everything for a child of 
three or four, instead of giving it the chance to find out for 
itself. Fortunate is the little one who has the spunk to say, 
“Let me do it!” 
If you of older years who read this book think there is no 
fun in science, ask your teachers to “let us do it.” We who 
are teachers are making our important discoveries, too; 
and slowly we are coming to see through our experience that 
constant “telling” is not teaching. 
So, the natural inclination of the human mind is to want 
to be allowed to have its way, profiting wisely by the ex- 
perience of the race in general, and by the practice of the 
scientists in particular; for, it would be short-sighted to 
neglect to use the ideas and the skill that men before our 
day have developed. We have no time to waste going over 
and over everything again, as if the field of knowledge were 
altogether new. 
The purpose of this book is to set before you some ideas 
about animals and plants as they have interested, and still 
interest, mankind. These ideas are stated very definitely, and 
are related to one another in such fashion as to demonstrate 
the degree of organization to which the science of Biology has INTRODUCTION 
3 
attained. Formerly, the books on biology made no mention 
of man at all, but now we are beginning to emphasize the 
relation that has always existed between man and other 
organisms. In fact, it is the very complex, and the very de- 
pendent, relations that man bears to the living things of the 
world, plants as well as animals, that makes the study of 
Biology naturally interesting and important. 
We have always lived surrounded by other creatures and 
by plants. In the time of our primitive ancestors long ages 
ago, man ranged the forests, taking his chances with the 
more ferocious animals, making use of others for food, for 
clothing, and for domestic purposes. The plants and their 
natural products he used for food and for shelter. To-day, 
our very civilization is characterized by the great number 
of uses we make of animals and of plants, as well as by the 
control we have gained over their multitudinous forms, 
and their productiveness. 
This control extends not only over the field of products 
which we use as food, medicine, clothing, and shelter, but 
also to the very existence of forms of life, and even to the 
creation of new varieties of plants and animals. Who has 
not heard of Burbank’s wonderful results in the creation of 
new kinds of plants out of older kinds? And who does not 
know of the vast experimenting that is going on in the breed- 
ing of animals for all possible uses? 
A great deal of the control over life and living things has 
come through the expression of the inborn curiosity of men 
who wanted to see what would happen in a given experiment 
thought out by them. But the mastery of life has always 
been in the hands of those men who have been trained, or 
have trained themselves, to think and work scientifically, 
with thorough knowledge of some basic facts and under- 
lying principles, and with definite understanding of how to 
go about it to learn more facts and more underlying prin- 
ciples. 4 
INTRODUCTION 
The road to becoming a “master of life” is not so long 
and difficult as you may think, for it does not necessarily 
mean becoming a scientific experimenter or investigator. 
The most immediate, and in fact the best, thing it can mean 
is for each one of us to become master of his own life. 
However, we cannot obtain control of our own living self, 
understanding it and our bodily processes, without a more 
or less extensive knowledge of other life. The reason is that 
man is the most highly developed of all living things, repre- 
senting in himself structures and processes which exist in 
more simple ways, and are studied more easily, in lower forms 
of life. But if this were the sole reason for learning about 
the less well known animals and plants, the study of life might 
prove dry and uninviting. As a matter of fact, life among 
the lowly of the air, the land, and the sea is extremely in- 
teresting in itself to read about as well as to study first hand. 
Persons do not have to be stimulated to take an interest in 
things that are capable of holding the attention naturally. 
It would be unfortunate, indeed, if a young person should 
miss the opportunity to start from his natural interest in 
living things, and with his increasing knowledge of life in 
general, develop real love for nature in all its phases. 
One of the aims of this book is to present the facts and prin- 
ciples of the subject of animal and plant life in such manner 
that you will want to go to the forests, the fields, and to the 
sea, where the other creatures live; and while doing so, will 
become better acquainted with your own bodily and spiritual 
self, and better satisfied with its possibilities, besides prob- 
ably finding in it a well of happiness the existence of which 
you may never have suspected. 
Moreover, the author feels that he is justified in having 
another important aim in writing this book, and that is to 
encourage in you the desire to go on and find out things for 
yourself during the time you are studying this book and 
afterward. The time you spend on the book is compara- INTRODUCTION 
5 
tively short, while a lifetime of possible experiences stretches 
out before you. If you learn the method of inquiring, and 
especially if you regain the desire to inquire, and conse- 
quently to think, you will surely be in a position to lead a 
happier life, for you will understand your environment, and 
be able to master it, instead of permitting it to master you. CHAPTER II 
TIIE SLIPPER ANIMALCULE AND ITS NEAR KIN 
If you are accustomed to thinking of animals as creatures 
that have exactly four legs and bodies large enough to com- 
mand your immediate at- 
tention and respect, you 
may be surprised to learn 
that probably the very 
first animals to exist and 
the most common to-day 
have no legs at all, and 
are not large enough to be 
seen unless you have a 
high-power microscope. 
Among the commonest 
is the Slipper Animalcule 
or the Paramcecium. As 
the drawing indicates, it 
has the general form of a 
slipper. If you are lucky 
enough to have the use of 
a compound microscope, 
you may find Paramoecia 
in abundance in jars of 
rotting hay that have 
been standing for at least 
three weeks. A small drop 
of water placed on a 
glass slide and adjusted on the stage of the microscope 
will contain many hundreds of tiny “slippers” shooting 
Fig. 1. Paramcecium. Much enlarged. 
A, left side; B, under surface; 1, cilia 
(“oars”); 2, mouth; 3, gullet; 4, food 
vacuole forming; 5, food vacuole in 
cytoplasm; 6, anus; 7, contractile vacuole; 
8, macronucleus; 9, micronucleus. (From 
Linville and Kelly: General Zoology; Ginn 
and Company.) 
6 AMCEBA 
7 
spirally hither and thither through the water. With a very 
highly magnifying lens in the microscope you may see the 
minute “oars” with which they swim. These are fine hair- 
like and very flexible short organs covering the entire body. 
With them the animals can swim either forward or back- 
ward. Forward means with the blunt end in front, although 
you will not find a head, or eyes, or any of the organs you 
might expect to find. 
At the inner end of a short gullet droplets of food and 
water form and periodically float away through the soft, 
jelly-like interior substance of the Parmoecium which is 
called protoplasm. You may see that digestion of the food 
is taking place, for the droplets get smaller and smaller. 
Waste particles are sent out from the body by means of two 
tiny organs called vacuoles that contract periodically, one 
after the other. A contracting vacuole makes one think of 
a toy balloon that is losing its gas. 
When a Paramoecium grows to its full size it begins to 
form a groove around the middle of its body. The groove 
deepens until the original animal has cut itself into two. 
Hut while the separating is going on each half forms a new 
mouth with all other organs necessary to its existence. 
This process is called reproduction. Through it the race of 
Paramoecia continues to exist. 
All the processes of this little animal are carried on by 
the living protoplasm of the body. The more fluid portion 
of the protoplasm, called cytoplasm, as already described, 
controls the nutritive or food-disposing work of the cell. 
The denser, more central portion of the protoplasm, called 
the nucleus, with an adjacent smaller body called the nu- 
cleolus, controls the reproductive process. 
Amoeba. A relative and in some respects a friend of 
the slipper animalcule is the Amoeba. The two little crea- 
tures are constructed on the same general plan, thus being 8 
THE SLIPPER ANIMALCULE AND ITS NEAR KIN 
relatives, and they live more or less together, existing on 
the same kind of food. There is plenty to eat for both, and 
so there is no occasion for their being enemies. 
Your expectations may now be adjusted to rapidly mov- 
ing objects, and to things still more striking than the Para- 
moecium. If they are, you must shift your effort to seeing 
a very small object that 
scarcely moves at all and to 
distinguishing a thing that 
looks not unlike scores of 
other apparently lifeless and 
formless clear specks. For 
the Amoeba even under the 
microscope moves almost as 
slowly as the hands of the 
clock, which you cannot see 
moving at all, and it is so 
much without form as to 
suggest the term formless. 
But it moves and it has not 
a form, but forms, and the forms are the direct result of its 
movement. And this is the way of it. 
The outer layer of protoplasm of which the body is com- 
posed has the power of extending outward little knobs or 
points, of jelly-like material in one or another direction. 
Into this knob the thin and granular protoplasm flows 
slowly, leaving other knobs that may previously have been 
formed on another part of the animal. The entire outline 
of the Amoeba is continually changing during its active 
moments. These little points and knobs are called “false 
feet” indicating their temporary character, for they may 
no sooner be formed than they are withdrawn into the uni- 
form substance of the animal. 
Amoeba is like most other animals in having to move to 
get something to eat. When it strikes against a Bacterium 
Fig. 2. Amoeba. Much enlarged. 
(From Linville and Kelly: General 
Zoology; Ginn and Company.) FORAMENIFERA 
9 
two adjacent false feet encircle the food, and very shortly 
the germ is taken into the animal and digested there. 
Reproduction takes place by a simple division into two 
parts, each part then growing to the size of the original ani- 
mal. As in the case of Paramoecium, there is a nucleus 
which controls the process of reproduction. 
Foramenifera. The heading of this section is a long 
word, but there is nc 
common term for the 
creatures that are in- 
cluded in the group 
which they comprise. In 
structure they are nearci 
like the Amoeba than 
like any other animal, 
but their bodies are cov- 
ered with a minute shell 
This shell has a large 
opening out of which the 
body extends. The name 
conies from the fact that 
the shell bears (Lat. fere) 
a n opening (Lat .foramen). 
There are at present anel there have been probably since 
the beginning of life upon the earth billions upon billions of 
these minute animals floating at the surface of the ocean. 
When they die their shells sink slowly to the bottom. In 
places the oozy bottom of the ocean contains countless num- 
bers of the shells. 
At various periods in the history of the world the floor 
of the ocean has been elevated, dried and hardened into 
stone. This means that much of the land upon which we 
live now was at one time under the water of the ocean. In 
the limestone especially, we can discover the shells of these 
Fig. 3. Foramenifera. Much enlarged. 
(Photograph. Courtesy of American 
Museum of Natural History.) 10 
THE SLIPPER ANIMALCULE AND ITS NEAR KIN 
Foramenifera. The limestone of Virginia and the chalk 
cliffs of the shore of England are masses of the shells of these 
microscopic creatures. 
The Malarial Parasite. Not many years ago people 
generally, and even physicians, thought that the disease 
malaria was due to poisonous vapors given off from low 
ground. Within the past twenty years scientists have proved 
beyond doubt that vapors have nothing to do with causing 
the disease. They have proved that a minute one-cell 
Diagram to show the life-history of the parasite in the body of man, as well 
as in the mosquito. A to L, red blood corpuscles, showing the development 
of parasite inside; M to W shows changes in form and position of the malarial 
parasite in the mosquito. (Redrawn from Chandler: Animal Parasites and 
Ilvman Diseases; John Wiley and Sons.) 
Fig. 4. The Malarial Parasite. Much enlarged. 
animal is the sole cause of it. This discovery has made it 
possible for us to begin intelligently a campaign to exter- 
minate the very disease itself. 
The malarial parasite is an unwelcome guest in the bodies of 
two hosts, ourselves and the Anopheles mosquito (see Chap. 
VII). This mosquito is not the common one, but one that 
happily for us lives in places where most people seldom go, 
in swamps and low ground and in forest ponds. The para- THE YELLOW FEVER PARASITE 
11 
site enters our blood when we are bitten by this mosquito. 
It increases in number very rapidly, and the young enter the 
red corpuscles of our blood, completely destroying all the 
corpuscles they enter. The stages of development through 
which the malarial parasite passes are extremely compli- 
cated. This made it very difficult for scientists to discover 
the life-history of the animal. 
Since the discovery of the malarial parasite communities 
have been able to reduce materially the number of cases of 
malaria. Evidently the parasite cannot exist if there are no 
Anopheles mosquitoes. Since mosquitoes of any species are 
nuisances, many towns, counties, and states are draining 
swamps, clearing out stagnant ponds, and putting in fishes 
that will eat the mosquito “wrigglers.” Sometimes undrain- 
able swamps are covered with crude oil which smothers the 
wrigglers when they come to the surface to breathe. 
The Yellow Fever Parasite. About the time of our 
Spanish War the cause of the yellow fever was in doubt. 
Many observations had been made, and a certain mosquito, 
this time the genus Stegomya was suspected of being con- 
nected with the transmission of the disease from person to 
person. In order to test the matter finally, a commission 
of three American physicians established an experimental 
camp in Cuba. In the course of the experiments two of the 
physicians became ill with yellow fever by permitting them- 
selves to be bitten by a mosquito that had under observa- 
tions previously bitten a man who had yellow fever. One 
of the three, Dr. Jesse W. Lazear, died. They had all risked 
their lives so that the science of medicine might have the 
evidence it needed. 
With the evidence thus obtained, the United States Gov- 
ernment, the Cuban Government, and other representa- 
tives of organized society have begun intelligent campaigns 
to eliminate this terrible disease. 12 
TIIE SLIPPER ANIMALCULE ANI) ITS NEAR KIN 
You may remember reading that when France tried 
to build the Panama Canal hundreds of workers died from 
this fever and from malaria. Later, our government by 
draining the mosquito swamps and by screening the 
houses in the Canal Zone was able to build the canal 
with practically no loss of life from these now preventable 
diseases. 
For a long time the yellow fever parasite could not be 
found. However, all the phenomena connected with the life 
history of the disease proved conclusively that a parasite 
similar to the malarial parasite exists. Although these facts 
were known, it was more than thirty years after the close of 
the Spanish War before Noguchi, the Japanese biologist, dis- 
covered the parasite. It is very small. 
Early in your study of science, one of the important and 
very interesting facts you will constantly be coming upon is 
that the truth about nature is easy enough to understand 
when your attention is drawn to it in a book, or when some 
one who knows tells you about it. Many facts, however, are 
within the power of anyone to see and understand, if only 
he uses his eyes, and more necessary still, his brain. But 
the great secrets, the riddles one might call them, many of 
which have defied the wisest men to discover, are made known 
only through the operation of the highest qualities of in- 
telligence mankind possesses. 
Necessarily, our greatest discoverers have always had a 
large stock of that wondering curiosity we all have as chil- 
dren. They have never ceased to want to know. Possibly, 
too, many scientists begin an investigation with the spirit 
in which we begin games. Only in their cases the game is a 
magnificent one, one that no person ever played through be- 
fore, one that calls for every bit of mental power they possess, 
one in which the end brings fame, possibly, but preferably the 
knowledge that the mind—onr human mind—has conquered 
this hitherto unconquerable difficulty. SUMMARY OF THE PROTOZOA 
13 
Summary of the Protozoa. The first of the great 
Branches of the animal kingdoms is called Protozoa. The 
word means simplest animals. The bodies of all are composed 
of hut one cell. The material of this cell is the semi-fluid, 
living substance known as protoplasm. At or near the center 
of the cell is the nucleus. This also is protoplasm, but it 
is denser protoplasm. The nucleus is considered the most 
important organ of the cell, because without it the cell dies, 
while the remainder of the cell may be lost and the cell still 
live. Protozoa is the only Branch of animals that have bodies 
of single cells. All other Branches have bodies of many 
cells, sometimes billions of cells. CHAPTER III 
SPONGES 
Who has not stood before a drugstore window and gazed 
at a display of sponges? How many allow their imagination 
to picture all the things that have happened to the sponges 
since they left their native ocean bed? But possibly a full 
account of their vicissitudes since death would not be nearly 
so entertaining as the story of their daily lives at home. 
For the sponge is a living thing, or rather it is many living 
things. There are sponges of very small size that are usu- 
ally single animals, but those that we are most familiar 
with are made up of several individuals so united together 
as to be indistinguishable. In a large display of sponges 
you will notice that many of the sponges show several con- 
spicuous “chimneys” opening upward. These indicate 
roughly the number of animals that are merged together to 
form the sponge “colony,” although it would be impossible 
to say just where the line of separation passes between them. 
The chimneys themselves and all the network of tough 
fibers make up what is called the skeleton of the colony. 
In life the skeleton is covered with living protoplasm, and 
through all the irregular spaces which connect directly and 
indirectly with one another there is a continuous sheet of 
this protoplasm. Down at the bottom where you see the 
even surface, a sharp knife severed the colony from its 
attachment to the rock upon which it grew. 
In your study of the Paramoeeium you learned about 
cilia, those minute hair-like organs that wave back and 
forth, pushing the animal through the water. Sponges have 
somewhat similar organs, but they are located in the irregu- 
lar passages. Their work is waving vigorously inward, main- 
14 SPONGES 
15 
taining streams of water, food and air which are absorbed 
directly into the tissue of the colony along the passages. 
If you open a sponge colony you will find that all the in- 
current passages connect with large interior spaces that 
lead finally to the chimneys. In life the chimney acts its 
part and carries off waste. This waste consists of excess 
Fig. 5. Colony of Deep-Sea Sponges. 
Skeletons of sponges mounted as a speci- 
men. (Photograph. Courtesy of American 
Museum of Natural History.) 
water and air, and of used-up material given off by the cells. 
Periodically, cells that take part in the reproduction of the 
colony are formed along the passages. The same colony 
may at one time form eggs, and at another, form male repro- 
ductive cells, the spermatozoa. The spermatozoa from one 
colony are drawn with the water into the canals of another, 
and there unite with the eggs, forming thus the embryos, 
young sponges, which later go out into the watery world 
and settle somewhere on a rock to take up the slow existence 
of their elders. CHAPTER IV 
JELLYFISHES AND CORAL POLYPS 
Medusae and Hydroids. You must have read the story 
of Medusa in your Greek mythology, and you may remem- 
ber why the hair of her head writhed and seemed like a 
mass of things alive. Biology is full of terms borrowed 
from Greek mythology, but often the reason for their use in 
the new connection is a fanciful one, as it is in the case of 
the medusae of jellyfishes. 
By the stretch of an imagination much less sedate and 
dignified than a scientific imagination you can see that the 
picture (Fig. 7) looks like the top of a person’s head, and 
that the row of pendant organs resemble snakes that are 
fastened by their tails. If you cannot imagine the resem- 
blance, you should see the medusae alive! For all of its 
oddity, the medusae is a real animal, living an independent 
existence, at least in the stage represented in the picture. 
Medusae are jellyfishes, and there are very many kinds 
of them. They all live at the surface of the sea. They are 
very small, many being microscopic. Some are beautifully 
colored, and all are capable of moving more or less grace- 
fully through the water. This is done by the contraction 
of a circular band of muscle fibers that run around the base 
of their dome-shaped bodies. During contraction of the 
body, water is forced outward through the opening shown 
in the picture, and the body goes forward, with the tentacles 
streaming out behind. 
Helpless as these tentacles appear to be, they are the little 
animal’s stinging battery for offense and defense. All over 
the surface of the tentacles are groups of minute cells, which 
16 MEDUS/E AND HYDROIDS 
17 
jn being touched, release fine, awl-like points that pierce 
:he skin of microscopic neighbors, and instill into their blood 
a paralyzing poison. So after 
all, there is something about 
these organs that suggests a 
dangerous animal, but they are 
not dangerous to persons. 
When a victim has been over- 
come, it is swallowed through 
the mouth and passes up, as 
it happens, into the primitive 
Fig. 7. Medusa. Much en- 
larged (After Allman). 
1, bell; 2, tentacle; 3, manu- 
brium; 4, radial tubes; 5, 
sense-organs. (From Lin- 
ville and Kelly: General 
Zoology; Ginn and Com- 
pany.) 
Fig. 6. Hydroid. Much enlarged 
(After Allman). 1, tentacles; 
2, 3, 4, stages in the formation 
of medusa. (From Linville and 
Kelly: General Zoology; Ginn 
and Company.) 
stomach located near the top of the dome. In four little 
pouches located on the radial canals, the eggs are formed, 18 
JELLYFISHES AND COILVL POLYPS 
in the females, and spermatozoa in the males. These cells 
pass into the water through the mouth opening, and the 
embryos are formed outside in the water. 
The subsequent history of the medusae leads us into an 
apparently new field, for the embryo develops into a thing 
that looks like a plant with roots, stem, and branches, and 
has a fixed position. In fact, when these plant-like colonies 
were first discovered they were given names independent 
of the medusae with which their life-history is really con- 
nected, the relationship not being suspected at the time. 
All the many species of these plant-like animals are called 
hydroids, because of their resemblance to Hydra (see Fig. 8). 
Each head of a branch is the main portion of a separate 
animal, the connection with others being established through 
the branches. Once in a while a little bud forms on the side 
of a hydroid, and gradually a medusa is formed. These 
separate and swim away, and continue their lives as de- 
scribed before. 
Hydra. Hydra is another monster, a fact which your 
mythology will verify. If water fleas and other micro- 
scopic folk could hand down to their descendants the stories 
of their trials and misfortunes, this fresh-water terror would 
have received unenviable fame long ago. 
Hydra is often a quarter of an inch in length, and no 
thicker than tine cotton thread. One species is brown, the 
other is green. Hydra lives in fresh water only, usually 
fastened temporarily by the basal end to a leaf or to a piece 
of submerged stick. The other end bears the mouth and a 
circle of six or more writhing tentacles. It is possible for 
Hydra to move from its place of attachment by slipping 
slowly on its basal end, and also by letting go its hold at the 
basal end, and crawling by its tentacles. Ordinarily, it 
waits until some swimming creature of suitable size strikes 
against its body, then it turns its tentacles about, envelops GIANT JELLYFISHES 
19 
it, stings it, and draws it inexorably toward its engulfing 
mouth. The victim drops into the digestive cavity, where 
it is gradually absorbed into the cells of the body wall. All 
unused particles are afterward forced outward through the 
mouth. 
This animal has two methods of reproducing the species. 
One method consists of forming buds 
on the surface of the body. These 
buds produce at the free end the mouth 
and tentacles, and subsequently sep- 
arate themselves from the parent. The 
other method is sexual; it consists of 
the union of eggs and spermatozoa, 
both kinds of cells coming from the 
same animal. 
Giant Jellyfishes. Many years ago, 
the Youths Companion published an 
interesting story of a New England 
farmer, who one morning after a heavy 
storm on the ocean discovered on the 
shore great quantities of jellyfishes. 
He had previously used various forms 
of animal fertilizer for his impoverished 
land, and it occurred to him that this 
mass of jellyfishes might be used for 
the same purpose. Accordingly, he 
carted many loads of the dead crea- 
tures, and spread them over a field. The next day he dis- 
covered that his field was obscured by a thin veil of dried 
jellyfishes. Their previously plump bodies had disappeared 
as sea water into the soil. The farmer was not aware of the 
fact that jellyfishes are over ninety-nine per cent water. 
The jellyfishes mentioned here are the large kind with 
which practically everyone who has been at the sea shore 
Fig. 8. Hydra. Much 
enlarged. 
Three young speci- 
mens forming by proc- 
ess of budding from 
older specimen. (Pho- 
tograph. Courtesy of 
American Museum of 
Natural History.) 20 
JELLYFISHES AND CORAL POLYPS 
is familiar. They are similar in general plan of structure 
to those described in a previous section, but they are differ- 
ent in life-history, and vastly larger in size. Moreover, they 
are the animals to which the name “jellyfish ” was first given. 
Fig. 9. Model of Jellyfish. (Middle of 
Picture.) Reduced. 
(Photograph. Courtesy of American Museum 
of Natural History.) 
Some of the species attain the size of eight feet in diameter, 
which after all represents comparatively little solid tissue. 
These animals have the circle of tentacles which in some 
species stretch out to many feet in length. The stinging 
cells are powerful enough to paralyze small fishes of three 
or four inches in length. The victims are drawn to the CORAL POLYPS 
21 
mouth at the center of the under part of the body, and then 
swallowed whole. The four large circular organs appearing 
in the body are the sacs which contain eggs or spermatozoa. 
The little embryos are formed in the water, and sink to 
the bottom and there form little cylindrical stalks which 
later divide up into parts that resemble saucers lying in a 
stack. The saucer-like young separate and grow to the 
size of adults in one season. 
Coral Polyps. Coral polyps naturally suggest coral 
islands, and coral islands suggest that vast, mysterious 
Fig. 10. Model of Coral Polyp. Reduced. 
Showing contracted and extended specimens. (Photograph. 
Courtesy of American Museum of Natural History.) 
stretch of ocean, the South Pacific, made famous by Robert 
Louis Stevenson and other writers of charming tales. 
Perhaps you think there is something queer about the 
word “polyp,” and that coral “insect” would be better and 
more accurate. But insect is a name used by many people 
when they do not know the right name for a small animal. 22 
JELLYFISHES AND CORAL POLYPS 
A polyp is the general name given to any of the fixed, soft- 
bodied animals described in this chapter. Thus the indi- 
viduals in a hydroid colony are polyps, and Hydra is a 
polyp. 
The coral polyp is a soft-bodied but tough, cylindrical 
creature varying in diameter from a fraction of an inch to 
a foot or more. You have seen masses of coral stone, and 
have noticed the crowded circular plates, with their radial 
ridges running from the center of each little circle. These 
mark the location of the polyps. In fact, the circles them- 
selves and the ridges, and the entire mass of the coral stone 
are formed by the polyps. This is done by the polyps se- 
creting or forming limestone at their bases and between pairs 
of thin sheets of radial partitions in their bodies. 
A mass of coral with the polyps actually alive and work- 
ing upon it is said to be a beautiful sight, especially when 
the tide covers them, and their tentacles are streaming 
out. Their colors mingle with the sea weeds and the bril- 
liantly colored fishes that swim in and out between the 
heads of coral and other living creatures. 
Summary of the Coelentera. The Branch of the animal 
kingdom to which the creatures just described belong is 
called the Coelentera. The form of all of them is more or 
less cylindrical, and their substance is soft. The single 
opening into the cavity of the body, the mouth, is sur- 
rounded by a circle of tentacles. Upon these tentacles are 
microscopic cells, which have the power of stinging the 
small victims which they prey upon, rendering them helpless. CHAPTER V 
STARFISHES AND SEA URCHINS 
The Starfish. When you saw the display of sponges in 
the drugstore window, you probably also saw one or two 
large star-shaped shells, beside something that naturally 
belongs in the last chapter, some sea-fans and some sea-pens. 
All of these things are frequently found together in the 
waters of the Bahama Islands, and in many other tropical 
seas. 
The large starfish is a giant of its kind. Most starfishes 
are small bodied, and have finger-shaped arms, usually 
five in number, stretching outward over an area of four to 
five inches in diameter. They are not fishes at all, any more 
than jellyfishes are fishes, but the name though given inac- 
curately still holds. 
In life these animals are reddish brown, or frequently 
reddish blue in color. The upper part of the shell is made 
up of somewhat flexible plates, mounted with many short, 
rigid spines. Under each arm there is a shallow groove ex- 
tending from the center of the body to the tip. Through 
minute openings in this groove, four rows of long, very flexi- 
ble and delicate, muscular tubes extend to the outside. 
When the starfish moves, it stretches these tube-feet forward 
and fastens them in turn to the rock, contracts the muscular 
fibers in them, and creeps along almost imperceptibly. 
Looking into a little pool left by the receding tide, one often 
may see several of the starfishes partially concealed between 
small stones, or humped curiously over something that 
appears to occupy their attention. Frequently investiga- 
tion has shown that in this position they are engaged in 
23 24 
STARFISHES AND SEA URCHINS 
Fig. 11. Model of Tidepool. 
Starfishes and sea-urchins at bottom of pool. (Photograph. Courtesy 
of American Museum of Natural History.) 
opening the shell of an oyster or a mussel. This they do by 
a slow and continuous pull in opposite directions, drawing 
on the outside by sucking their tube-feet to the surface of THE SEA-UltCHIN 
25 
the shell of the victim. At length the oyster or mussel gives 
up the fight, the muscles of the victim relax, and the valves 
of its shell separate. The starfish then performs the strange 
feat of turning its stomach inside out through the mouth 
opening, and enveloping the soft flesh of its exhausted prey. 
Before this habit of starfishes was discovered, serious inroads 
were made upon beds of oysters, and even now starfishes are 
enemies that the oyster “farmer” has to reckon with. 
Although starfishes have no head, they have eyes, and 
these occur singly at the ends of the arms. They are prob- 
ably not of much service to the owners, but keen senses of 
smell and of touch take the place of eyes. 
There are male and female starfishes. The eggs and the 
spermatozoa are sent out into the water, where they unite, 
forming embryos that swim about in the water for some time 
before changing to the crawling form of the adult. 
The Sea-Urchin. Not far away from the starfishes in 
kinship, and often in locality, one may find something that 
looks at first like a flattened rubber ball, covered all over 
with sharp spines, sometimes very long ones. This is the 
sea-urchin (see Fig. 11). The spines are movable, and in 
one Pacific Ocean species they are used for boring holes in 
rocks for concealment. 
In among the spines, arranged radially as in the star- 
fishes are rows of long slender tube-feet. These tube-feet 
often emerge high on the sides, as well as beneath the dome 
of the body. By means of them, the sea-urchins move at 
very much the same rate of speed that is characteristic of 
the starfish. 
The mouth is at the center of the under surface, and is 
surrounded by five bony teeth, pointed toward one another 
from the sides. Having no movable arms, they cannot open 
oyster shells. They feed altogether on seaweeds, and thus 
are not a menace to our own food supply. 26 
STARFISHES AND SEA URCHINS 
The eyes of the sea-urchin are located in a circular row 
about the center of the top. Here they really occupy po- 
sitions similar to the positions of the eyes of the starfish, for 
they are at the tips of the regions of the tubefeet. This is 
one of the interesting proofs found in the structure that the 
sea-urchins are relatives of the starfishes. 
There are other animals that show many of the same points 
of resemblance. They are all classed together under the 
name Echinoderma, because of the possession of spiny skins. 
Summary of the Echinoderma. The two animals 
described in this chapter belong to the Branch called Echino- 
derma, which means “spiny skinned.” The two forms men- 
tioned, as well as many others allied to them, are constructed 
on a radial plan, in which usually five divisions of the body 
extend from a common.center. The body is covered with 
short spines set on a more or less hard, limy shell. The 
organs of locomotion are muscular “tube-feet,” which ex- 
tend to the exterior, fasten to the rocks, contract, and cause 
the body to move forward slowly. CHAPTER VI 
THE EARTHWORM AND ITS KINDRED 
The Earthworm. Nobody respects earthworms, but 
nearly everyone is benefited by their existence. The boy 
who digs up a canful of them out behind the barn finds 
pleasure in the chase for the worms, and still keener 
pleasure in thinking of what he will do with them. The 
fishes that steal them from the hook get considerable 
satisfaction out of the miserable little impaled bodies. 
Robins breakfast on them upon the lawn, and the farmers 
and all the rest of us have a better breakfast because of what 
the earthworms are doing and have been doing since earth- 
worms began to exist. 
Indeed, earthworms were among the first of farmers, for 
the effect of their activities is to turn the soil over and over 
again. Except in winter, they are constantly burrowing 
through the earth, swallowing some of it for the food it con- 
tains, and dissolving particles that would otherwise remain 
undissolved. The natural and easy way for them to get rid 
of an intestine full of earth is to allow it to go through the 
body at the surface of the ground. Doubtless you have 
seen many of these coiled little masses of earth where the 
grass is short or thin, but you may not have understood their 
meaning. 
Charles Darwin, the great English naturalist, took the 
trouble to carry on observations extending through many 
years, in order to get some notion of exactly how much work 
earthworms do along this line. He covered a field with cin- 
ders and stones of small size, and found that these afterward 
disappeared. He found that the earthworms brought up 
27 28 
THE EARTHWORM AND ITS KINDRED 
soil in their bodies, and spread it out on top at the rate of 
one-fifth of an inch a year. The practical meaning of this 
for us is that sticks, leaves and other bits of dead things are 
covered up, and their decay and return to the minerals of 
the soil and the gases of the air is hastened. Furthermore, 
the holes made by the earthworms convey water and air 
to greater depths than would be possible without the holes. 
Plowing is much less in extent than is the overturning of 
the soil by earthworms. The plowing done by the farmers 
Fig. 12. Earthworm in Burrow. Reduced. 
1, The “saddle” of animal; 2, earthworm casts 
from intestine; 3, bristles on the segments. 
(Pen drawing.) 
lias the effect of being an imitation of the work done by 
the earthworms. But while the farmers know what they 
are doing, and usually why they are doing it, the earth- 
worms do not know and cannot know the effect of their 
activities as they bear upon the welfare of mankind. 
You can generally distinguish the head of the earthworm 
by the direction of its movement, although it can move 
backward when necessary. The only visible organ of the 
head is the pointed lip with which it grasps bits of leaves 
and draws them into its burrows. There are no eyes or THE EARTHWORM 
29 
other visible sense organs. However, it can feel a physical 
shock, as you may learn by walking near one lying at the 
opening of its burrow in the early morning. 
Everyone has seen earthworms crawling, and knows that 
their bodies extend and contract. But when they operate 
these muscles, they use their tiny bristles on the under sur- 
face for levers. If you don’t mind allowing one to crawl 
through your fingers you may feel the bristles, and may 
even see some of the largest of them. 
Internally the earthworm has a very complicated set 
of organs. The digestive canal consisting of gullet, crop, 
gizzard, and intestine, extends through the body. A circu- 
latory blood system takes up the digested food and carries 
it where it is used by the tissues of the body. Air that is 
needed comes in through the soft, slimy skin, and liquid 
waste is passed out through a pair of complex tubes in each 
ring or segment of the body. Earthworms have a micro- 
scopic brain just behind the lip in the head, and from the 
brain a pair of nerves pass downward and along beneath 
the intestine. Certain organs in the body called ovaries 
and spermaries give rise to the eggs and spermatozoa. The 
eggs of one animal and the spermatozoa of another unite, 
and grow into embryos in a tough little sac that is deposited 
in the ground. 
The peculiar way in which earthworms breathe is respon- 
sible for their presence in large numbers on the ground after 
a rainstorm. Water running into the burrows forces out 
the air contained in them. Water itself contains a little 
air usually, but not enough for earthworms in the confined 
space of the burrow. So the animals are forced out into the 
cold world. After the rain, you may see them struggling to 
get back to soft earth where they can make another bur- 
row, for there is no reason to believe that they can find their 
old ones, or would care to do so. A rainstorm especially in 
cities and towns brings disaster to earthworms, many losing 30 
THE EARTHWORM AND ITS KINDRED 
their lives in the hazards of paved streets and cemented 
sidewalks. 
The Sandworm. One of the main reasons for men- 
tioning the sandworm here is to show that two animals may 
be closely related, and still differ widely. 
The sandworm lives in the mud in bays of the ocean. 
It has burrows, too, but these burrows are often deserted 
Fig. 13. Sandworms in Mud (Model). Reduced. 
(Photograph. Courtesy of American Museum of Natural History.) 
by their owners. Sandworms can swim vigorously and very 
beautifully with their numerous paddles. Where the sand- 
worms have paddles the earthworms have only the bristles 
which in the sandworms give stiffness to the paddles. 
Being an active animal and often going far, the sandworm THE TAPEWORM 
31 
has feelers with which it feels its way in narrow places. On 
top of the head there are four eyes. Both of these animals 
are quite well adapted to their surroundings or environment, 
but it is evident that the 
earthworm represents a 
type that is less complete 
than the sandworm, al- 
though both are well 
adapted to their place 
and method of living. 
The Tapeworm. The 
tapeworm (Fig 14) is 
still less complete than 
the earthworm. It is a 
real degenerate among 
animals. The explana- 
tion of this fact is that 
it lives in a special en- 
vironment where it has 
to make no effort what- 
ever to get its food. 
Living in the intestine 
of other animals upon 
which it is a parasite, 
the tapeworm has- no 
eyes, or other sense or- 
gans. It has no mouth, 
no stomach, or intestine, 
and no blood system. 
But it has muscles and a nervous system, and also a simple 
system of tubes by which the animal rids itself of its own 
liquid waste. It also has organs for reproduction. 
Tapeworms are found in the bodies of cattle, horses, sheep, 
pigs, dogs, cats, and in many other quadrupeds (four-footed 
Fig. 14. The Tapeworm. Reduced. 
The youngest segments are near the head; 
the oldest, containing mature eggs, at end 
of body. (Redrawn from Chandler: Ani- 
mal Parasites in Human Disease, John 
Wiley and Sons.) 32 
THE EARTHWORM AND ITS KINDRED 
animals), and also in human beings. The head of the para- 
site fastens itself by suckers or hooks to the lining of the 
intestine, and the rest of the body, sometimes many feet in 
length, extends into the cavity of the host’s intestine. Oc- 
casionally, several of the end segments separate from the 
parasite, and pass out with the undigested portion of the 
victim’s food. If by chance these segments come into food 
or water that is con- 
sumed by some quad- 
ruped, the embryos 
which the segments con- 
tain will pass down to 
the intestine of a new 
victim. 
The embryos have 
the power of boring 
their way through the 
wall of the intestine 
into the muscles. There 
the embryos come to 
rest and remain until 
the possible death of 
the host by some other 
agency. The flesh of 
this animal when eaten carries the inclosed embryo into the 
stomach of a new victim. Thereupon, the membrane 
surrounding the embryo dissolves, the embryo makes its 
escape, and at once attaches itself to the lining of the 
intestine of the new victim. In this place, it begins to 
grow long, and to steal from its host as did its ancestor 
before it. 
Government inspection of meats has exterminated to a 
large extent this parasite and others of similar kind from 
human beings. Of course, cooked meats cannot carry the 
parasite in injurious condition. 
Fig. 15. Heads of Tapeworms. Much 
enlarged. 
Left, with sucking disks for attachment to 
interior of intestine; right, with sucking 
disks and hooks. (Redrawn from Chand- 
ler: Animal Parasites in Human Disease, 
John Wiley and Sons.) THE HOOKWORM 
33 
The Hookworm. Another parasitic and degenerate 
type of animal is the now well-known hookworm. It lives in 
the intestine of human beings. A few years ago it was dis- 
covered that the existence of these terrrible parasites ex- 
Fig. 16. The Life-History of the Hookworm. Enlarged. 
A, male and female; B, egg; C, young embryo in soil; developed young in 
soil; young in stage ready to enter soles of bare feet of person. (Redrawn 
from Chandler: Animal Parasites in Human Disease, John Wiley and Sons.) 
plains in large measure the shiftlessness and the physical 
weakness of that class of our fellowmen in our Southern 
states known as the “poor whites.” For some unknown rea- 
son the Negroes of the South are immune to the hookworm. 
The hookworm lives in its adult stage in the intestine of 34 
THE EARTHWORM AND ITS KINDRED 
its victim. It burrows into the wall of the intestine, suck- 
ing the blood, and instilling into it a poison which tends to 
prevent the blood from coagulating. Internal bleeding may 
thus continue for some time; hence the pale appearance of 
the sufferers. 
The eggs and the embryos of the hookworm pass out and 
often exist for a time in vaults or on the ground. From the 
surface of the soil some of the embryos make their way 
through the skin of the feet of children and even of grown 
persons, for many adults go barefoot in the South. From 
the muscles of the leg the embryos bore their way into blood 
vessels, and are thus carried along to the heart and lungs, 
and finally to the throat. It is then possible for them to 
pass down the gullet to the intestine, where they complete 
their development, carry on their parasitic life, and reproduce. 
Thus, it appears that the contempt with which the Negroes 
and everyone else have always regarded the poor whites 
probably has no justification whatever from the point of view 
of civilization. It is the tragedy of what was once the stock 
of a great people, for the ancestors of the poor whites were 
the pioneers who opened the wilderness, and made it pos- 
sible for our nation to exist at all. The South regards the 
hookworm as one of its most serious economic problems, and 
has begun a campaign of sanitation and education for its 
poorer people. The cure of the disease is comparatively 
simple, but its prevention and extermination depends upon 
the ability of the people to learn methods of cleanliness and 
sewage disposal. This, however, may require a long time. 
Incidental to economic changes going on in the South, 
many entire families of the poor whites are being employed 
in the factories. There they live in large measure away from 
the kind of places where they formerly were exposed to the 
ravages of their enemy, the hookworm. On this account, 
the discoverer of the hookworm in the South, Dr. C. W. 
Stiles, maintains that the poor whites are far better off in SUMMARY OF THE “VERMES” 
35 
the mills that they would be on the land. There may be 
some doubt of this, however, since the chief interest of many 
mill owners in the poor whites is probably not in their racial 
regeneration, but rather in the product of their labor. 
Indeed, it has been necessary for the public-spirited men 
and women of the nation to come to the rescue of these 
twice-blighted people, and to start a crusade to stop child 
labor in the Southern mills. The poor whites themselves 
have begun to demand opportunities to work out their own 
economic and spiritual regeneration in their own homes, 
and upon the land. 
Summary of the “Vermes.” In an old system of 
classification of animals a Branch called “Vermes” was gen- 
erally used. Although the Branch has long been subdivided 
into other branches, it is still useful when it is not necessary 
to be technical. 
The Vermes are long, slender animals with the body di- 
vided into numerous somites or segments of similar form and 
size. When appendages are present they occur on every 
somite, and serve as locomotor organs. Except in degener- 
ate species, worms have a continuous digestive tract from end 
to end of the body. Blood vessels conduct the blood and the 
digested food about the body. Above the mouth there 
is a small brain, and from it extends a double nerve chain, 
which encircles the gullet, and then runs along the under side 
of the intestine to the hinder end of the body. CHAPTER VII 
INSECTS AND THEIR NEAR RELATIVES 
The House-Fly. There was a time, and not many years 
ago, when the nursery rhyme, 
“Baby-bye, here’s a fly; 
Let us watch him, You and I,” 
indicated the indulgent attitude of civilized mankind toward 
these numerous and over-familiar members of the tribe of 
insect. As a more accurate expression of feeling in the 
matter at present the author suggests, 
“Baby-bye, here’s a fly; 
Let us ‘swat’ him, You and I.” 
At the same time, the habit of “swatting” or killing flies, 
though relieving our pent-up feelings of wrath and disgust, 
really does very little good. Even kind persons apparently 
find satisfaction in seeing flies dead, being impressed with 
the concrete evidence of their prowess. The author once 
counted 789 dead house-flies that he had captured in one 
day by the use of fly-paper. But during the time he was 
preparing the paper and counting the flies, he might have 
been employed more efficiently by doing something to pre- 
vent the existence of house-flies. 
The operations of communities are slowly becoming more 
intelligent in the matter of dealing with the house-fly and 
the trouble it carries on its feet. Part of our campaign 
against house-flies has been waged indirectly through the 
great popularity of the automobile. It is said that in certain 
36 THE HOUSE-FLY 
37 
districts of New York City, where private and public horse- 
stables were formerly very numerous, house-flies were an 
ever present pest. The places of these stables have been 
taken largely by automobile garages. The direct result has 
been a very great reduction in the number of house-flies in 
that portion of the city. 
House-flies breed in stable manure and in garbage. The 
Fig. 17. The House-Fly. 
a, The insect is shown here regurgitating or “unswallowing” some of its 
food, thus making possible the distribution of typhoid bacteria it may have 
consumed; b, Foot and leg of insect. Filth and bacteria could be held among 
the bristles. (From Ross: The Reduction of Domestic Flies.) 
complete elimination of these materials by removal, or by 
treatment with chloride of lime, would eliminate house- 
flies within one season. It is only by the cooperation of 
entire communities that the desired result may be brought 
about. But we shall get cooperation only after long effort. 
When public sentiment becomes strong enough in this as in 
any other matter, vigorous and effective action will be taken. 38 
INSECTS AND THEIR NEAR RELATIVES 
But why should we try to get rid of all the flies? Because 
it is now known that one of the ways typhoid fever is carried 
is by the “germs” being transported on the feet of the flies 
from the common breeding ground of the two organisms. 
Rid ourselves of flies, and we rid ourselves of one of the means 
in which human beings contract typhoid fever. Is it not 
worth while to give 
intelligent battle for 
the protection of our 
kind? 
The house-fly lays 
about one hundred 
fifty eggs. These 
hatch in one day as 
footless, white “grubs” 
or larvae. They feed 
on the material about 
them, and within a 
week form around 
themselves a tough, 
brown case. They re- 
main in this pupa 
stage (Fig. 18) for less 
than a week, at the 
end of which time 
they emerge as adult flies of full size, with their six legs, 
two wings and other organs completely formed. There are 
no “baby” flies, unless one considers the larvae as such. In 
a short time the young female flies may lay eggs. This 
goes on all summer, and enormous numbers of the pests 
are produced. 
The Mosquito.——Some of the most important points in 
connection with the life of the mosquito have already been 
dealt with in Chapter II. In this place the life-history and 
Fig. 18. Pup« of House-Fly on Rotting 
Cloth. 
(From Ross: The Reduction of Domestic Flies.) THE MOSQUITO 
39 
also the means of recognition of the mosquito, will be 
given. 
Everyone is fairly familiar with the tiny “wrigglers” 
that by jerking their apparently weighted bodies back and 
forth make their way downward from the surface of the water 
in a rain barrel, or in a pool of water. These are the larvae 
of the mosquito. Possibly not so many persons have seen 
the little boat-shaped mass of eggs floating on the water, 
but it can be seen if one is looking for it. The larvae change 
Fig. 19. Mosquito “Wrigglers.” 
The black mass or “boat” is composed of eggs which are 
hatching. The wrigglers are escaping and swimming 
downward. (Model. Courtesy of American Museum 
of Natural History.) 
their skins, or they “molt” a few times, living in the mean- 
time on microscopic impurities in the water. They breathe 
through a small tube at the hinder end of the body, by float- 
ing with the tube opening to the air, and the body hanging 
downward. That is what they are doing when you jar the 
barrel, or come near enough to frighten them. Their habit 
of breathing at the surface has given the scientist his oppor- 
tunity of attacking them at one of the most vulnerable 
points in their lives. Kerosene oil poured upon the water 
covers the breathing tubes of the larvae, and smothers them 40 
INSECTS AND THEIR NEAR RELATIVES 
as well as any eggs that may be unhatched. Incidentally, 
every other living thing in the water has its supply of air 
cut off. 
The pupa stage follows the larva stage in a few days. 
The pupa is active, swimming by its tail, and breathing by 
tubes on the middle of its back. Naturally, the pupae also 
are destroyed by the oil treatment. After a few days in the 
Fig. 20. Mosquito Control. 
Kerosene oil is pumped over the swampy region infested with 
mosquitoes. The oil resting on the water destroys all life by 
excluding air from all breathing surfaces touched. (Photo- 
graph. Courtesy of American Museum of Natural History.) 
pupa stage, the young mosquitoes come to rest at the sur- 
face, and the adult forces its way through a break in the skin. 
The mosquitoes that bite you are all females. Few per- 
sons have ever seen the males to know them. They suck the 
juices of flowers, and apparently never trouble us. Several 
other blood-sucking species of flies have similar differences 
of habit. There may be an advantage to the species in the 
opportunity the habit of blood-sucking affords in obtaining TIIE HONEY-BEE 
41 
in a short time a considerable amount of rich food already 
prepared. The energies of the female may thus be given 
more immediately to egg-laying. 
It is important for one to be able to recognize especially 
the dangerous malarial mosquito, and to relieve our minds 
of anxiety by being able to distinguish it from the ordinary 
mosquito. The malarial mosquito (Anopheles) comes to 
rest with all its legs on the support, and the hinder end of the 
body tipped upward, while the common mosquito (Culex) 
rests upon its first four legs, the hinder pair being stretched 
backward and upward without touching the support. In 
Culex the beak is directed downward, while the body is 
horizontal to the support. In Anopheles the body and beak 
are in the same plane. We speak of the malarial mosquito 
as being dangerous; but it should be understood that it really 
is not dangerous until after it has bitten a human being who 
has malaria. The chances of this happening in a malarial 
country are of course considerable. 
The Honey-Bee. Everyone has a good word to say for 
the honey-bee. It has been held up as a model of efficiency 
for human beings and as a satisfactory demonstration of 
what we ourselves could do in living and working together 
for the common good, if we only would. Efficient they cer- 
tainly are, but many other insects are quite as much so. 
Working for the common good as we understand it involves 
the solution of pressing problems and the meeting of new 
difficulties incident in minds that are active in the human 
attribute of thinking. Honey-bees have no new problems 
to solve, and they do not think. But they are worth our 
interested study, nevertheless. 
Colonies of honey-bees contain many thousands of in- 
dividuals. There are a few hundred males in the early part 
of each season, and all the rest are females. One of the fe- 
males, called the queen, is larger than the others, and per- 42 
INSECTS AND THEIR NEAR RELATIVES 
forms the exclusive labor of laying eggs from which the 
young hatch. The remaining females do not have the power 
to lay eggs, and for that reason are said to be sterile, and are 
called “neuters.” They are also given the name workers, 
because upon them devolves all the 
labor of the colony. The males 
are called “drones,” because they 
do no work at all. Nevertheless, 
they are necessary since they fer- 
tilize the eggs to be laid by the 
queen. After their function is per- 
formed, they are all cast out of the 
hive to die, or they are killed by 
the workers, and are then thrown 
out. 
Owing to an intelligent selection 
of productive varieties made by 
breeders of bees, an enormous 
quantity of honey is often produced 
in a single season,—much more 
than the bees themselves need. 
There is nothing unusual about 
such an act on our part, and it is 
quite in line with our way of levy- 
ing upon nature for our pleasure 
and sustenance. We require many 
other animals to put forth far more 
than the amount of energy that 
would be requisite to keep them in 
food. Thus it appears that we 
ourselves are responsible for the remarkable industry of the 
honey-bees. But we did not invent their skill in mechanical 
construction, nor do we even know the chemistry by which 
they transform the simple nectar of flowers into the delec- 
table honey. 
Fig. 21. Swarming of 
Honey-Bees. 
The first of a lot of swarm- 
ing bees when alighting 
cling to some exposed sur- 
face. The remainder cling 
to these, and form a solid 
column sometimes several 
feet long. Many thou- 
sands of these insects make 
up this column. (Photo- 
graph. Courtesy of Amer- 
ican Museum Natural His- 
tory.) THE HONEY-BEE 
43 
A large quantity of honey eaten by the workers furnishes 
the raw material from which they distill small quantities 
of wax in little pockets on the under side of their bodies. 
Other workers than those that furnish the wax, take it and 
mold it into the familiar honeycomb. The six-sided form 
of the cavities naturally results from the crowding of soft, 
cylindrical cavities of the same size, because each cylinder 
is touched by six other cylinders. 
The next step in the work of the colony is the collection 
of nectar from the flowers. The nectar is sucked up by the 
tongues of the bees from the bottom of the corollas of the 
flowers of many species of plants. On the same visits the bee 
may collect in shallow pockets on the outside of the hind legs 
little pellets of pollen. The nectar is swallowed as far as the 
“crop,” a pouch next to the gullet, and there changed chem- 
ically into honey, and then “unswallowed” into the cavities 
of the honeycomb. When a cavity of the comb is filled, it 
is sealed with a thin layer of wax. The pollen is made into 
“bee-bread” to feed the young. 
Certain cavities of the comb are reserved for the “nur- 
sery.” In each of the cells in this department the queen 
deposits an egg. When the eggs hatch, the workers in charge 
feed the young with honey mixed with liquid material from 
certain glands opening into the mouths of the nurses. Soon 
the food is changed for bee-bread; that kind of food is given 
to the larvae until they are full grown. The cavities are then 
sealed by the workers. In the cavities, the larvae spin thin 
cocoons of silk about themselves, and slowly change into the 
adult form, finally cutting their way out. This is the his- 
tory of the production of workers. 
In the early part of the season, or in emergencies later in 
the season, queens are produced in a most remarkable way. 
Three cavities are turned by the workers into one by tearing 
down the partitions. If there are eggs in all three cavities, 
two of the eggs are destroyed, and the remaining one when 44 
INSECTS AND T1IEIR NEAR RELATIVES 
hatched is fed throughout its larval life with “royal jelly,” 
a whitish jelly-like material produced from glands in the 
mouth of the workers. 
When the young queen emerges from the cocoon there is 
an interruption in the business of the hive, and mortal fray 
begins between all the young queens, if several emerge at 
the same time. This continues until all but one have been 
slain by royal stings, a weapon that is used only for this 
specific purpose. If but one queen emerges while an older 
queen is in possession, the old queen tries to kill the young 
one, but is usually prevented by the workers from doing so. 
In that case the older queen is forced out of the hive, and 
takes with her a considerable number of workers and drones. 
This is called the “swarming” (Fig. 2l). If new hives are 
not available, the new colony will find a hollow in a tree, and 
proceed to construct a home in it. The young queen left in 
the old hive, flies from the hive for a time with the drones. 
In this flight the eggs are fertilized by the drones. The 
queen then returns to the hive and settles down to her work 
as egg-layer to the colony. 
All the activities of swarming are connected with the need 
of keeping the species alive. Without swarming the colonies 
would become too large for convenient management, and 
would tend to destroy themselves by overcrowding. Human 
beings seem in a measure to be imitating the bees when they 
migrate from the crowded countries of Europe, and from the 
crowded regions of our own country to less crowded parts. 
Both bees and people are greatly benefited by the change. 
Ants. Around a summer camp, or on an excursion, 
or even on a short trip through the woods, you must have 
come upon small colonies of ants while turning over flat 
stones. What a hurrying and scurrying you must have 
seen! In July you often see ants with wings running to 
safety with the wingless and more active ones. These winged ANTS 
45 
ants are males and females, and the others are workers or 
neuters. 
You would scarcely believe the winged ones ants at all, 
if it were not for the ant-like form of their bodies, and for 
the fact that the workers seize the winged ones, and hasten 
their flight into the tunnels beneath. Two or three workers 
often cooperate in dragging their queens along. 
Fig. 22. Ant Colony. 
Section of large ant hill, showing the habitation of many thou- 
sands of ants, and indications of numerous tunnels. (Photo- 
graph. Courtesy of American Museum of Natural History.) 
There are other burdens and responsibilities to be looked 
after in the serious emergency of unwarranted invasion by 
the tyrant man. Little cream-colored oblong bodies, some- 
times nearly as large as a grain of wheat, are picked up in 
the jaws of the workers one at a time. These are the pupae 
or cocoons in which the young pass the last stage of their 
existence just before emerging as adults. The eggs one 
seldom sees because they are very small. The larvae also 
are inconspicuous. 
One fact that is very impressive when one observes the 46 
INSECTS AND THEIR NEAR RELATIVES 
commotion of the ant colony disturbed in this way, is that 
the worker individuals are not afraid for their own safety 
at all. Their sole concern seems to be the safety of their 
dependent ones, the less active males and females and the 
undeveloped young. This habit is at the bottom of their 
success as colonial tribes, and incidentally provides the inter- 
est that all human beings have in ants. We are in the habit 
of holding up these insects, and bees also, for our own kind 
to pattern after. 
As we ourselves classify emotions there appears to be no 
selfishness whatever in the individual ant for its own wel- 
fare, but there is extreme “ selfishness ” for the colony. How- 
ever, we might call this emotion for the large group by the 
name of patriotism, as we do when we give a name to our 
concern for country. Beside patriotism ants have high 
courage in battle with other colonies, and even with higher 
animals and with man himself. This courage is manifested 
effectively through a pair of tong-like jaws, operated by a 
set of muscles in head and body that make ants in general 
strength veritable insect Samsons. 
For a few days in August the male and female ants from 
different colonies of the same species leave their nests under 
rocks or in hills, and fly through the air, mating meanwhile. 
Sometimes at night during this time they will visit the camp- 
fires of man literally in thousands, rushing to their death in 
the flames. After the so-called marriage-flight the males soon 
die, and the females drop to the ground, and pull off their 
own wings. Or the wing-pulling may be done for them by 
the workers that discover them. 
In the new colony, which may be started in some cases by 
the queens even without the cooperation of workers, the 
queen is soon busy with laying eggs, and in emergencies with 
rearing the young until there are enough workers to do this 
work. A queen is capable of laying thousands of eggs. 
The eggs are placed in special chambers in the nest, and ANTS 
47 
are watched over and the young fed by the nurse-workers. 
In some cases, at least, it is known that food for the young 
is obtained from glands in the mouths of the workers very 
much as is done by honey-bees. Adult ants eat animal and 
vegetable food. Some species, such as the agricultural ant 
of Texas, actually raise certain grasses on their hills, and 
harvest and store the grain obtained. Other species levy 
upon species of plant-lice for “honey-dew.” This is obtained 
from two minute knobs on the backs of these little crea- 
tures. The ants stroke the backs of the plant-lice, and 
the little servants liberate a small amount of their liquid 
secretion. In apparent exchange for this, the ants often 
care for the plant-lice through the entire year, keeping 
them in their nests during the winter, and taking them to 
the trees and other vegetation to forage during the warmer 
seasons. 
There are many counter suggestions against the advice 
that man is inclined to give himself, while holding up some 
other species as a model. It is likely that man does not 
take his own advice seriously when advocating the virtues 
of bees and ants. And there is a point of historical interest 
in the fact that what man has come to believe is wrong 
for him to do, for example, to hold slaves, has long been done 
and in all probability will always be done by certain species 
of ants. Curiously enough, also, the workers of one species 
are so dependent upon their slaves that they cannot feed 
their own young, or even themselves, being able only to 
fight. Now, mankind has learned that those who, for one 
reason or another, do not look after or care for their own 
young cut themselves off from the most blessed of human 
experiences. Ants would never learn that, for they do not 
think. They look after their young, of course, but they can- 
not try a new way of doing it. That is beyond their capac- 
ity. Let us not take our life-ideals from the ants. Man is 
his own best stimulator and example-giver. 48 
INSECTS AND THEIR NEAR RELATIVES 
Wasps. Nine o’clock was just a trifle late for break- 
fast, and the cook was very deliberate about getting it ready, 
but it was a pleasure nevertheless to wait at the margin of 
the mountain road, while she worked over the “deviled” 
caterpillar, gnawing it, pounding it, and turning it over and 
over, until it was just right for the palates of the little white 
wasp larvae in some nest 
not far away. There is 
nothing like waiting, if 
you really want to see Na- 
ture in actual operation. 
Wasps are what are 
called predaceous insects; 
that is, they capture other 
animals, chiefly insects and 
spiders. In some cases 
they immediately kill the 
victim and make mince 
meat of it for the young. 
In other cases they sting 
the prey, as they do with 
spiders, paralyzing the ner- 
vous system, but allowing 
the victims to remain alive 
until the young of the 
wasp are hatched, and can 
turn about and devour 
their helpless cell-mates. Wasps also feed upon the sweet 
products or the sap of plants. If one visits your plate of 
bread and jam while you are in camp, it may be not only 
generous, but it may be even wise, to permit it to take a 
nibble in peace. Do what you like with what they leave; 
it has not been harmed. 
Even without the experience, you probably know that 
wasps can sting—and they will. The famous injunction, 
Showing two cells still sealed with wasp- 
made paper, the cells containing par- 
tially developed wasps. An adja- 
cent cell shows a young wasp about 
to emerge. (Photograph. Courtesy 
of American Museum Natural His- 
tory.) 
Fig. 23. Wasp Nest. GALL-FLIES 
49 
“Do not annoy the animals,” may be said to apply with 
especial force to wasps. At the same time, a person may 
walk along the road and meet hundreds of them from sum- 
mer to summer, and never be stung at all. Even if you are 
stung by chance, a paste of baking soda, or even of mud, 
will soon make you forget your troubles. The worker and 
the female wasps have stings, but the males do not. 
Some kinds of wasps live in colonies, and for that reason 
are called social wasps; the individuals of other species live 
by themselves, and are called solitary wasps. Naturally, 
the social wasps live a more interesting existence. A colony 
starts in the spring of the year with a female that has lived 
alone through the winter in some crevice under old bark, or 
about barns or houses. She builds a simple nest by chew- 
ing up bits of weathered wood and flattening it out into 
layers, which are formed into six-sided cavities grouped 
together very much as the cells in the honeycomb are 
arranged. In one genus, Polistes, the small comb is sus- 
pended by a short stalk to the under side of eaves of roofs 
or logs. Another genus, Vespa, commonly known as “yellow 
jackets” or hornets, makes the same kind of combs one 
above another, leaving high galleries between, and covers 
the whole with layers of the same material, strong enough 
to protect the interior from storms. 
The main work of making the nest is done by the workers, 
which soon begin to appear from the first eggs laid by the 
female. After the colony is quite large, and in the early 
autumn, males and females develop from the eggs. The 
males fertilize the eggs in the females, and soon after die. 
The workers also die on the approach of cold weather, and the 
females are left alone to weather the storms of winter. 
Gall-Flies. So many persons are curious about “What 
makes those little lumps on this leaf?” that some account 
of the insects that cause the lumps seems necessary. 50 
INSECTS AND THEIR NEAR RELATIVES 
There are several kinds of insect that make lumps or balls 
of various forms on leaves; some are real flies, members 
of the same order as the house-fly, some are plant-lice, but 
the great majority are members of the same order as the 
bee and the wasp. It is incorrect to call them flies, but the 
name given many years ago still clings to them. 
The Gall-flies are all small insects, so small that most 
persons do not distinguish them from many others. The 
Insect has just emerged from gall in which it developed 
from egg. (From Linville and Kelly: General Zoology; 
Ginn and Company.) 
Fig. 24. Gall Insect. 
females lay their eggs under the epidermis of the young 
leaves of oaks, witch-hazel, willow and other trees, and also 
on the leaves and stems of weeds of many kinds. When the 
larvae hatch, they appear to irritate the plant tissue adja- 
cent to them, causing it to swell up into a form of enlarge- 
ment which is characteristic for each species of gall-fly. 
That is, from the form of the gall, a specialist can determine 
the species of the insect that caused it, without seeing the 
little creature at all. 
When the larva has grown to its full size by feeding on 
the interior of the gall, it commonly changes to the pupa THE JUNE-BUG 
51 
stage, and when the adult form is produced, tunnels out, 
and flies away. 
By cutting carefully into a green gall, one can usually 
see the little larva, or several of them. Sometimes one can 
find scores of inhabitants in different stages of development, 
varying from larvte to adults. In some cases, members of 
the motley group are guests, uninvited to be sure, but still 
allowed to remain. 
The June-Bug. For several nights in succession one 
summer, the author had the curious experience of having 
Fig. 25. June-Bug. 
1, Pupa; 2, grub; 3, side view of adult; 4, upper sur- 
face of adult. (Courtesy of American Museum of 
Natural History.) 
his camplights visited at exactly ten minutes to nine o’clock 
by scores upon scores of lusty June-bugs. Clocks might have 
been set by their coming. But let no one assume that June- 
bugs are by nature adjusted to keeping time, for they are 
clumsy, blundering fellows, likely to upset and disarrange, 
rather than to put in order, the life in a camp or in an un- 52 
INSECTS AND TIIEIR NEAR RELATIVES 
screened room, and they will do it after dark, in the summer 
season, if you have an exposed light. 
Everyone who does not know already is likely to wonder 
where these big, brown beetles come from so suddenly, and 
where they stay in the daytime. They come from the trees 
near by, where they have been feeding upon the leaves, 
sometimes doing considerable damage. The larvae, too, 
make extensive levy upon plants, feeding at the roots of 
many kinds in meadows and gardens. They are the fat, 
white grubs with brown heads that one comes upon 
while spading. Pigs and fishes find them much to their 
liking. 
The pupa stage is passed in a chamber in the ground, 
and emerges in May, becoming at that time very noticeable. 
It has been suggested by some authorities in insect lore that 
a better name for these creatures would be May-beetles, 
and accordingly they are thus called by some. 
The Lady-Bug. Most persons regard with patronizing 
indulgence the little hemispherical lady-bug, with its red or 
Fig. 26. Lady-Bug. 
Larva at left; pupa in middle; adult at right. (Cour- 
tesy of American Museum of Natural History.) 
yellow shell-like wings and black spots. It looks so much 
like an animated and ornamented bead running up and down THE CLICK-BEETLE 
53 
on your clothing, that its appearance provokes amusement 
rather than fear. It is nevertheless a dangerous animal to 
certain other insects, the scale-insects (Fig. 31), those 
lowly forms that prey upon our fruit trees, especially apples 
and oranges. It is probably not too much to say that we 
should have been deprived of all the oranges that come 
from California, and possibly in time of all that come from 
Florida, if it had not been for the timely importation from 
Australia and from China, of twro species of lady-bug that 
preyed upon scale-insects. The scale-insects had been im- 
ported unintentionally with orange trees from those coun- 
tries. 
One reason that lady-bugs are so effective as scourges of 
these insect pests is that the lady-bug larvse also feed upon 
the same insects. With the old and the young making war 
against them, the scale-insects have been kept in a partially 
subdued state. This is more than man could have done 
alone. 
The larva seems far less peaceful and amusing than the 
adult. In fact, it looks as if it would be a nuisance to man; 
and doubtless many of them are killed by him on account 
of their appearance. They are abundant in early June on 
the leaves of trees. The larvse have flattened, tapering 
bodies, and are about a half inch long, with black ground 
color and dark reddish spots and tufts of short spines, 
rather ugly all in all. The only effective defense for the 
lady-bug larva against man’s enmity against insects in gen- 
eral is knowledge on the part of man. It is obvious, too, 
that here and elsewhere knowledge is the best protection 
against man’s interference with his own welfare. 
The Click-Beetle. You are probably familiar with the 
fact that many insects, especially beetles, “play ’possum.” 
That is to say, they draw up their legs against the body, 
lie on the back, and remain quite motionless until it appears 54 
INSECTS AND THEIR NEAR RELATIVES 
to them that the danger is over. If you are patient, you 
may see them slowly extend a leg or two, and cautiously 
right themselves, and scamper away. But you may not be 
prepared for the click or snap, as 
of a hidden spring, that has hurled 
a little brown insect several inches 
into the air. If it falls back down- 
ward, snap! it will go again, and 
again, until it alights feet first. The 
snapping is done by the muscles of 
the head and middle-body (thorax) 
operating across the joint between, 
causing the head to strike suddenly 
against the ground. 
The larvae of the click-beetles you 
seldom see. They are hard, light- 
brown, and round, and are called 
wire-worms, because of their resem- 
blance in form to a bit of wire. 
They are about an inch in length. 
They are extremely abundant, and 
their food necessities cause considerable loss in the crops of 
corn or other grain. 
The Fire-Fly. In these days of a popular movement 
for efficiency, the attention of experts in artificial lighting 
has been drawn by scientists to the high efficiency of the 
phosphorescent light of the fire-fly. It is known that when 
the fire-fly makes its light under the control of its nervous 
system by a form of oxidation, it produces no heat at all. 
Man has never been able to produce light without at the 
same time setting free, and wasting, a considerable amount 
of heat. In burning kerosene, gas, or electricity for lighting, 
a great deal of energy escapes as heat, and we have not 
learned how to prevent the waste. The fire-fly has unknow- 
Fig. 27. Click-Beetle. 
(From Kellogg: American In- 
sects; Henry Holt and Com- 
pany.) THE BLACK SWALLOW-TAIL BUTTERFLY 
55 
ingly given us a suggestion, and elec- 
trical experts are trying to see what 
can be done with it. 
Fire-flies look like flies more than 
like beetles, which doubtless accounts 
for their being called flies. Their 
wing-covers are flattened and soft, 
being quite flexible. Their bodies are 
less than one inch in length, and are 
dark-colored and sometimes margined 
on the wings with yellow lines. 
Some of the fire-flies fly in the 
daytime, and are abundant on the 
golden rod. 
The Black Swallow-Tail Butterfly. In the early morning 
of August days, one often sees black swallow-tail butter- 
flies balancing on gorgeous thistle blossoms. It requires 
little skill to approach and watch them as they thrust their 
quivering, black, tubular probosces into the slender flowers 
of a thistle head, for there is a bountiful supply of nectar 
there for them and for other insects whose tongue or probos- 
cis is long enough to reach it. 
The butterflies never give up any of their nectar to man 
or to their young. They keep it for themselves, swallowing 
it as it is drawn from the flower. And when they are through 
with a particular flower, they coil up their tubular pump- 
ing organs like a watch spring and fly away. That is the 
reason you seldom see the proboscis while the butterfly is 
resting on a leaf or a twig. 
The swallow-tail butterflies, of which there are several 
species in this country, bear an extension at the back of 
each hind wing. There is thus a fancied resemblance to a 
swallow’s tail. The general color of the wings is black. 
There are two rows of circular yellow spots across 
Fig. 28. Fire-Fly. 
(From Kellogg: Ameri- 
can Insects; Henry 
Holt and Company.) 56 
INSECTS AND THEIR NEAR RELATIVES 
both pairs of wings, and another row around the margin. 
The spots are brighter colored in the males than in the 
females. 
Over the head and body of the butterfly there is a mat of 
Fig. 29. Black Swallow-Tail Butterfly. 
Larva at left; pupa suspended from wood by silk woven by cater- 
pillar; adult above. (From Dickerson: Moths and Butterflies; 
Ginn and Company.) 
long, soft hairs. Over the wings there are microscopic 
scales. These are thin plates, growing from the membrane 
of the wings, and overlapping like the shingles on a roof. 
All butterflies and moths have these scales. Although the AMERICAN SILKWORMS 
57 
color pigments are in these scales, it is impossible to detect 
any color in single scales. 
Of course, you are aware of the fact that many species of 
animals could not recognize their own young, if the task of 
doing so were presented to them. And we cannot blame 
them, for in nature all that many of them have to do with 
their young is to respond to the stimulus to produce eggs 
which in turn produce the young. 
After the eggs of butterflies and many other groups of 
insects come the larvae, which are so different from the 
adults in form and in habits of life that close studies of the 
development had to be made before scientists were sure of 
the connection of larvae with particular adult forms. Early 
zoologists believed that the caterpillars, for example, really 
contained an insect in adult form, and that the form of the 
caterpillar was only a mask for what was concealed within. 
Therefore, they gave to all such animal stages the name 
“larva,” which is the Latin word for mask. Nowadays, 
we know that the adult form does not exist in the larva, 
but gradually develops from the complete breaking down of 
all the larval organs and the construction of new ones. 
The larva of the black swallow-tail butterfly is a smooth 
green caterpillar with black rings around the body, and with 
scattered yellow spots. Like other caterpillars, it feeds with 
biting mouth-parts, and lives on wild parsnip leaves, and 
other plants of a similar kind. When full grown, it attaches 
itself to the under side of something in a protected place, 
changes to a triangular pupa, anchoring itself with a strand 
of silk (see Fig. 29). From this pupa case, not a cocoon, 
it emerges in two broods in June and in August. 
American Silkworms. While the trees are busy with 
producing their harvest of nuts and winged fruits, their 
leaves are yielding up some of their substance to fattening 
the aldermanic bodies of some giants among the race of 58 
INSECTS AND THEIR NEAR RELATIVES 
caterpillars. In August and September, while the hickory 
nuts, chestnuts, and acorns are ripening, and you are look- 
ing about for some hoped-for early ones, your surprised 
nerves will some day pull you up suddenly at the unexpected 
presence of a bigger caterpillar than you ever saw before. 
Fig. 30. American Silkworm. 
Larva below at left; pupa in cocoon at right; adult above. (From Dickerson: 
Moths and Butterflies; Ginn and Company.) 
And the caterpillar may be as much surprised as you are, 
if its clumsy efforts to get over the ground rapidly are any 
indication of its feelings. 
There are few larger caterpillars than the larvae of several 
species of American Silkworms. The largest of the silkworm 
caterpillars is the Cecropia moth caterpillar. It grows to 
the length of about four inches. It has been described by AMERICAN SILKWORMS 
59 
the late Professor Comstock as “dull bluish green in color. 
The body is armed with six rows of tubercles, extending 
nearly its entire length, and there is an additional short 
row on each side on the under surface of the first five seg- 
ments following the head.” The larva lives on the leaves 
of many species of forest trees, and on apple and plum 
leaves. 
When the leaves have fallen from the trees, the cocoons 
of this and other species of silkworms may be seen attached 
to the twigs. When the caterpillar is ready to pass into 
the pupa stage it finds a place of attachment, and begins to 
spin silk from certain glands in its mouth, first making a 
band of silk about the twig to insure its staying on its sup- 
port. Then the larva begins to roll itself up in a seemingly 
endless thread of silk. At the conclusion of this process, 
the caterpillar is inclosed in an extremely tough waterproof 
silken shell, where it remains until the following spring. 
Cutting into the cocoon one would find a brown, mummy- 
like pupa, still alive, but powerless to do anything except 
to wiggle its abdomen slowly. The caterpillar has ceased to 
exist in every particular. But the outlines of organs of the 
future adult form are present on the surface. They are the 
feelers, the wings, the legs, and the mouth-parts,—all or- 
gans of the adult form. 
When the period of transformation is over, the adult 
splits its brown shell along the middle of the back, and 
crawls out, leaving its mummy-case behind. It then cuts 
its way out of the cocoon. On the surface of the cocoon, 
the young moth rests probably exhausted after its ardu- 
ous labor of coming into its new life, and meanwhile its blood 
flows into its soft rumpled wings, filling them out. When 
the surface tissues are hardened, as they are in an hour or 
two, the moth is ready to fly away. 
The adult of the Cecropia moth is about six inches wide 
in stretch of wings. The chief color of the body is dusky 60 
INSECTS AND TIIEIR NEAR RELATIVES 
brown. Distinguishing marks are a red spot near the apex 
of the forewings, and near the center of each wing a crescent- 
shaped white spot bordered with red. 
The silk of these silkworms is not commercially valuable. 
The Ant-Lion. In the soft earth, under the eaves of 
the cabin in the woods where this account is being written, 
there are perhaps one hundred small funnel-shaped pits. 
They are less than two inches in diameter, and seem at first 
to have been made possibly by the dripping of rain water 
from the roof. But it is bright sunshine now, and a rain- 
drop, which at present does not exist in this place, could not 
create that commotion in the microscopic depths of the pit. 
A small ant has toppled into the hole, and is trying to 
get out. Every time it tries to crawl up, the unsteady 
slopes give way, and besides, an eruption beneath carries up- 
ward a fine shower of particles of earth. Finally, the ant 
slips all the way to the bottom of the crater, and some con- 
cealed living thing seizes it. 
If you try the experiment of making a little disturbance 
at the margin of the pit, with a stick or with a particle of 
earth, the chances are you will learn nothing, except that 
the hidden creature appears to know the difference between 
you and its usual victims. But gently excavate the loose 
earth of the pit, and if you are looking for something motion- 
less, with six legs and the color of earth, you may find the 
ant-lion. It will be “playing ’possum.” 
After several minutes, the ant-lion will exhibit a nervous 
sign of life by giving two or three twitches backward into 
the soft earth. If left undisturbed it will build itself another 
pit by pushing the earth backward with its abdomen, prob- 
ably throwing some earth up with the aid of its head. 
Ant-lions are very abundant under the edge of cliffs, or 
under the eaves of buildings in the country. 
The pupa of the ant-lion is formed by the larva surround- SCALE-BUGS 
61 
ing itself with grains of earth, and lining the covering with 
silk. 
The adult is a four-winged insect, with netted wings and 
slender body, about half the size of a dragon-fly, which it 
somewhat resembles. 
Scale-Bugs. The little brown specks on the surface 
(Photograph. Courtesy of American Museum of 
Natural History.) 
Fig. 81. Scale-Bugs. 
of oranges look quite harmless, and so they are, as far as 
your personal health is concerned. But they are not harmless 
to the orange tree when present in large numbers. As has 
already been said in a previous section, one of the main INSECTS AND THEIR NEAR RELATIVES 
62 
reasons they are not present in large numbers is the fact 
that the lady-bugs destroy them. 
Scale-bugs live on the bark and to some extent on the 
fruit of apple, pear, cherry, orange, lemon, and many other 
fruit trees, in conservatories, and on pine trees and other 
forest trees. They perforate the bark of the tender shoots, 
the epidermis of the leaves and of the fruits, and suck the 
juices of their plant victims. They always interfere with the 
best growth of the plants, and sometimes kill them. 
Some of the scale-bugs form about themselves a white 
powdery wax which resembles cotton. Others secrete a 
flat scale of wax under which the insect lives. Still others 
have a flat form, but secrete no scale. The females are wing- 
less. The males have one pair of wings, and after they have 
reached the adult form, lose their mouth-parts, and thereafter 
have no way of taking food; yet they live for a long time. 
To fruit-growers scale-bugs are a constant menace. The 
activities of the lady-bug must be supplemented by the use 
of sprays of lime, sulphur, etc. 
The reputation of the family to which the scale-bugs 
belong is partially saved by certain ones which furnish dye- 
stuffs. The best known of these is cochineal. The dried 
bodies of these insects are ground up to make the dye. One 
species secretes a resinous wax from which shellac, a valu- 
able varnish, is made. 
Grasshoppers. A few score grasshoppers springing 
up more or less airily as we walk along through the grass of 
the meadow suggest nothing of devastation and nothing 
of famine. But the author’s early childhood was strongly 
impressed one summer in the ’70’s with seeing the 
sun obscured as in an eclipse with swarming myriads of 
famine-bringing grasshoppers. He recalls seeing a fine field 
of green corn, on his grandfather’s farm in the Missouri 
River Valley being visited in the early morning of a mid- GRASSHOPPERS 
63 
summer day by millions of grasshoppers. In the afternoon, 
nothing but the stumps of the corn plants remained. Not 
satisfied with the corn and other green things, the insect 
hordes consumed everything eatable, beside some things 
not considered eatable, namely, harness leather. 
Occasionally, there are small migrations of this Rocky 
Mountain Locust, but the farmers now know more about 
their habits, and can prevent their former great destructive- 
A, B, Females laying eggs; C, nest of eggs; I), a nest excavated; E, a 
few eggs separated. (From Linville and Kelly: General Zoology; Ginn 
and Company.) 
Fig. 32. Red-Legged Grasshoppers. 
ness. A near relative of the Rocky Mountain Locust is the 
red-legged locust or grasshopper. It never becomes a serious 
menace. 
There are many other kinds of locusts or grasshoppers 
distributed throughout the country. There is the giant, 
wingless grasshopper of the South and West, the Clouded 
Locust of dirty-brown color, that makes a crackling sound 
with its wings when flying, and the Carolina Locust with 
dust-colored upper wings and yellow-bordered under wings 
showing in flight. 
You may have heard the expression, “Some men plan 
their future like grasshoppers,” which means they do not 64 
INSECTS AND THEIR NEAR RELATIVES 
plan at all. For, as it goes in the story of the Ant and the 
Grasshopper, the grasshopper “sings” and eats all summer, 
and loses its life in the fall. But this is not until eggs are 
laid in the ground, or in logs or stumps. 
These eggs lie in their places through the winter, hatching 
in the spring. You may recall that you never see grass- 
hoppers until the summer is pretty well under way, and even 
then only small, wingless ones. These wingless young 
correspond to the inactive pupae of the beetles and the butter- 
flies and moths. Thus, the grasshoppers never have a great 
change in their bodily form, their development being gradual. 
Every time they increase in size, however, they split the 
skin along the middle of the back, and crawl out, the soft 
skin swelling suddenly, and the wings and other organs 
growing quickly before the skin has time to harden again. 
Summary of the Insecta.——The group of animals just 
described makes up the Class called Insecta, or the insects. 
They come into very close economic relation with man, 
and hence are better known than are most other Classes. 
Insects have bodies that are divided into three regions, 
head, thorax, and abdomen. On the head are the eyes, the 
mouth, the mouth-parts consisting of appendages, and anten- 
nae or “feelers.” The thorax bears the wings, sometimes 
one pair and sometimes two pairs, as well as the three pairs 
of legs. The abdomen is composed of clearly defined somites 
(sections or segments of the body), approximately ten in 
number, and the somites are not provided with appendages. 
The digestive tract extends from end to end of the body, 
and is quite complex. Colorless blood in a complete system 
of vessels carries digested food from the intestine. The 
nervous system is constructed on the same plan as it is in 
Vermes. Reproduction takes place usually by means of 
eggs and spermatozoa, which are developed first from ova- 
ries and spermaries inside the bodies of females and males. THE LOBSTER 
65 
The Lobster. After a considerable sojourn in the air 
and on the earth of the forest, the field, and about the homes 
of man, following the lives of insects, let us return to that 
vast environment where life probably began—the sea. 
Persons who study animals in 
the sea have often expressed 
wonder at the marvelous va- 
riety of form and color ex- 
hibited there. Although the 
water looks pretty much the 
same wherever you are, there 
are many factors that bring 
about very complex condi- 
tions, indeed. For example, 
the temperature varies with 
the depth and with the dis- 
tance from the equator, and 
with the nearness of great 
ocean currents, like the Gulf 
Stream. There is the variety 
of depth itself, and of light de- 
pendent on the depth. There 
are rocky and sandy shores, 
and inlets filled with river 
water from the land, and there 
are islands of soil and of coral. 
Wherever there are crevices 
or chasms, there seaweeds 
abound, and among the seaweeds crowd multitudes of sea 
creatures seeking escape from one another, and securing it, 
too, by unconsciously imitating in color and in form the 
general or special features in the environment. 
Here and there we find animals that gain protection 
from others by being too small to be seen. Such are the 
medusae described on page 16. Others cling to the bodies 
Fig. 33. Lobster. 
(Photograph. Courtesy of Ameri- 
can Museum of Natural History.) 66 
INSECTS AND THEIR NEAR RELATIVES 
or live within the bodies of larger and more assertive kinds 
of seafarers. These are the parasites. There are the sea- 
rovers themselves, the strong ones that prey upon the little 
ones, or take their chances of escaping the teeth of others 
perhaps a little stronger. They are the whales, the sharks, 
the porpoises, and the sword-fishes. 
A large number of sea animals bear on the outside of their 
bodies heavy or crust-like coverings, such as the clams, 
mussels, crabs, and the lobsters. 
As successful as any of these has been the lobster. What- 
ever lessening in number the lobster has suffered, and it has 
suffered much, has been due to man himself. The lobster’s 
shell is no protection against the devastation of man. 
Before the flesh of the lobster came to be so much prized 
by those who set and those who follow’ the fashions in eating, 
there w ere lobsters in the sea that seemed large enough to 
hold their own even in a physical contest with man, if they 
had been disposed to exert themselves. The giants of the 
race weighed over twenty-five pounds, and were over two feet 
in length. Nowadays, the largest are so small that the stories 
of large ones are likely to be discredited as “fish stories.” 
Lobsters belong to a group of animals that have the head 
and thorax united into one piece as far as the shell is con- 
cerned. The abdomen is composed of six segments jointed 
together. The head has two pairs of antennae instead of 
one as in the insects. The eyes are on movable stalks, a 
fact that enables them to see about them more easily. There 
are six pairs of complicated mouth-parts, which wrork side- 
ways in holding and chew’ing the food. 
The large claw’s or nippers are constructed like the first 
two pairs of legs, but are larger and adapted to holding and 
crushing their prey, which sometimes consists of clams. 
The third and the fourth pairs of legs end in a point. The 
abdomen is provided writh smaller organs of “ Y” form W’hich 
are called swimmerets. SPIDERS 
67 
The lobster can walk slowly when partially supported by 
the buoyancy of the water. Its most successful method of 
locomotion is by swimming. This it does by suddenly con- 
tracting the muscles in the abdomen, and catching a large 
amount of water in the scoop-like flange of the tail. The 
result of the contraction is to send the body backward with 
great force and swiftness. 
When the female lobster is about ten inches long she lays 
several thousand eggs which immediately cling by their 
glutinous surface to the swimmerets, and remain there un- 
til the next spring when the young hatch. The young at 
once float to the surface of the water, where they molt several 
times, growing larger by stages. When they are not an inch 
in length they sink to the bottom, and from that time on 
remain there, living under seaweeds and under the pro- 
jecting ledges of rocks. 
Owing to the great demand for lobsters in the market, 
they are protected by law in all the maritime states, but 
rather inadequately protected. The consequence is that 
lobsters are captured and sold before they have had the 
chance to reproduce, being immature. Naturally, this means 
extermination in comparatively few years. It is easy to 
see that law-makers should have studied biology. 
Spiders. Spiders are among those unfortunate beings 
that suffer calumny and often death at the hands of man 
because of an undeserved reputation, Nearly everyone 
shrinks from a spider, while freely permitting the house-fly 
to walk over his hands, his face, or even over his food. Yet 
the spider is doing its natural best to exterminate the greater 
enemy of man. 
Grown persons at the present day have largely ceased 
teaching children to dread imaginary “bears,” “witches,” 
and the “bad man.” When we have prepared a generation 
of boys and girls with the facts about some of the unfairly 68 
INSECTS AND THEIR NEAR RELATIVES 
dreaded animals, teaching them incidentally to dread the 
really dreadful ones, we may hope that the children of the 
future may be the truly great of our nation, by showing 
their superiority to the superstition and ignorance of the 
present. We must acknowledge that it has been ignorance 
and false teaching that has made us lenient with the house-fly. 
May it not have been ignorance 
and false teaching that has made 
us dread the spider? 
Spiders live in dark corners 
and in protected places to escape 
their enemies, among whom are 
man and the wasp. They come 
out into the open to capture 
their food, or to secure it when 
it is entangled in their webs. 
The mouth-parts which enable 
spiders to overcome their insect 
prey are the pair of sharp pointed 
claw-like mandibles. Near the 
point of each mandible is a mi- 
nute hole through which poison 
passes into the body of the vic- 
tim. When persons are bitten 
by spiders, this poison sometimes has no effect at all. 
Oftener it seems to cause about the same soreness as the 
bite of mosquitoes, or sometimes as the sting of bees. Only 
rarely does serious inflammation result. 
Spiders are often spoken of as insects, but they are not 
correctly classified as such. Spiders all have eight legs, 
borne upon the thorax of the body. The abdomen is a sac- 
like division of the body without segments. There are eight 
eyes on top of the head, but in spite of the large number they 
cannot clearly see with them at a distance of more than 
four or five inches. 
Fig. 34. Garden Spider. 
Male at left; female at right. 
(From Cambridge Natural His- 
tory, Macmillan Company.) CENTIPEDES 
69 
At the hind end of the abdomen are three pairs of organs 
called spinnerets, from which the silk is spun out. The silk 
is used by the web-forming 
species to construct en- 
meshing traps for their prey. 
In all species of spiders silk 
is used to contain the eggs; 
it is used for tubes or 
passageways by the ground 
spiders, and for “floats” by 
the “flying” spiders. 
The young of spiders are 
hatched in the silken sacs. 
In some species the sac of 
young is carried about by 
the mother for awhile at 
the end of her body. After 
hatching, the young in some 
species ride on rhe mother’s 
back for a time, but soon 
leave and provide for them- 
selves, after the manner of 
their species. 
Centipedes. O n the 
plains of Texas and north- 
ward, there is a species of 
centipede that measures five 
or six inches in length, and 
this one is said by the cow- 
boys to be poisonous. But 
the cowboys are much given 
to telling improbable tales 
to amuse themselves, and the chances are small that this 
many legged, and not very handsome, creature is dangerous. 
Fig. 3.3. House Centipede. 
Common about houses, not poisonous. 
(From Farmers’ Bulletin, U. S. Dept, 
of Agriculture.) 70 
INSECTS AND THEIR NEAR RELATIVES 
In the Eastern states one frequently finds under decaying 
logs and under stones a small species of centipede, not more 
than one and one-half inches in length. 
Centipedes are slender, flattened, segmented animals 
with horny, brown covering for each segment or somite. 
Each segment bears a pair of jointed legs, ending in a point. 
The head supports a pair of heavy mandibles, similar to the 
mandibles of the spider in general form, and adapted to a 
similar use. 
Summary of Arthropoda. The insects, the lobster and 
its kin, the spiders, and the centipedes, are members of a 
great Branch called Arthropoda. The name is made up of 
two Greek words which signify “animals with jointed feet.” 
The appendages referred to as feet are more accurately called 
legs. As legs they bear the bodies of their owners sometimes 
with considerable swiftness and directness. 
In number the legs vary from six in the insects to eight 
in the spiders, to ten in the lobster and its near relatives, and 
to many in the centipedes. The skin of the legs always, 
and sometimes the skin of the body, is made up of a horny 
layer. This acts as an outer skeleton which serves to pro- 
tect the inner parts, and also to make possible the activities 
of running, swimming, and flying, which require rigid as 
well as flexible sections of the body. 
All the members of the Branch have a distinct head, with 
complicated eyes, slender, jointed feeling organs, hard, 
biting organs and other mouth-parts which move from the 
sides to meet in the middle line. The remainder of the body 
is divided into a variable number of sections called “somites” 
or segments. These are grouped in all except the centipede 
into the two body divisions called thorax and abdomen. 
The thorax bears the legs and the wings whenever these 
organs are present. 
On the abdomen, and sometimes on the thorax, there are SUMMARY OF ARTHROPOD A 
71 
minute openings called spiracles, which are the entrances 
of the system of breathing tubes that permeate the body. 
By means of the tubes called trachece, every organ is supplied 
with oxygen, and from every organ carbon dioxide is carried 
to the exterior. 
The young of all the Branch hatch from eggs, and in some 
groups they pass through two distinct stages in development 
before they reach the adult stage. In the adult stage eggs 
are laid again for the next generation. CHAPTER VIII 
MUSSELS AND THEIR KIN 
The Fresh-Water Mussel. The destruction of animal 
life has become so much an incident of the lives of human 
beings as to be accepted for a matter of course. In fact, 
as our civilization advances, and our real or supposed needs 
increase, new industries develop and become enlarged and 
systemized for still greater levies upon life other than 
our own. 
It is not generally known even in the region concerned 
that several states of the Mississippi Valley contain fresh- 
water mussel fisheries. Those operating these fisheries 
dredge the bottoms of the rivers for mussels, destroy the 
animals, and cut their two-valved shells into disks and 
make buttons of them. This is the source of our familiar 
pearl buttons. Occasionally, rounded pearls of considerable 
value are found in the sand or mud, or in the softer parts of 
the animals. 
Men and muskrats are the greatest enemies of the fresh- 
water mussels. Against neither has the bivalve any effect- 
ive defense. Down in the mud and sand it plows its way 
laboriously along, seldom visible except for a fringed opening 
through which food and water and air enter between the 
valves. A passing shadow of a rake, or of the body of its 
furry pursuer, will cause the mussel to withdraw its food- 
siphon, but probably too late. 
In an aquarium, fresh-water mussels can be observed with 
comparative ease. A thick fleshy “foot” is the plowing 
organ. This muscular organ extends forward from between 
the valves, pushing aside the mud, drawing after it the rest 
72 THE FRESII-WATER MUSSEL 
73 
of the body. This foot and the fringed siphon are the only 
organs of the body that appear outside the shell. 
The mussel is an animal without a head, and without eyes. 
The food, consisting of microscopic animals and plants and 
air, is drawn in by the siphon 
at the hinder end of the body. 
This incoming material is car- 
ried along by the action of 
microscopic thread-like lashes 
called cilia, similar to the loco- 
motor organs described in the 
Protozoa. After passing thus 
along the cavities outside the 
body proper, the food reaches 
the mouth, a tiny opening sur- 
rounded by four thin triangu- 
lar tentacles. The air passes 
over two pairs of thin-ribbed 
“gills” that spread out broad 
and flat over the sides of the 
body. Outside the body and 
the gills, and lining the valves, 
are two thin layers of muscu- 
lar tissue which are called man- 
tle-folds. It is between them 
and the closely fitting valves 
that pearls are sometimes 
formed. These valuable by- 
products of mussel life are 
probably caused by the irritating presence of a parasitic 
worm that crawls between the valve and the mantle. 
Without the help of a very important “friend-in-need" the 
mussel would have a hard time in life. This friend, or rathei 
friends, are various species of fresh-water fishes. When the 
embryo mussel reaches a certain stage in the gills whicl 
Fig. 36. Fresh-Water Mussel. 
External layer of shell removed, 
showing material from which 
buttons are made. (Photograph. 
Courtesy of American Museum 
of Natural History.) 74 
MUSSELS AND THEIR KIN 
serve as “brood-pouches,” the young are forced out into 
.the water. They fall to the bottom, and lie there open with 
the back of their tiny shells downward. From the small body 
proper a thin sticky thread floats upward into the water. 
A fish swimming along near 
the bottom comes in contact 
with this thread. The em- 
bryo is thus picked up, 
whereupon it clings to the 
skin, or to the gills, of the 
fish by two small hooks that 
grow out from the margin of 
each valve. A fold of skin 
forms on the fish over the em- 
bryo, which thus becomes a 
temporary parasite. After a 
few weeks when the young 
mussel has reached a more 
advanced stage of develop- 
ment, the inclosing skin dis- 
solves, and the mussel falls 
out, and makes for itself a 
home in the mud, possibly 
many miles away from its 
birthplace. The friendship 
of the fish is after all not 
friendship, since it is not in- 
tentional. 
The Soft-Shell Clam. Some fine morning at the sea- 
shore when the tide is out, and a broad mud and sand flat, 
firm enough to walk upon happens to be within walking 
distance, you may take it into your head to go out as far 
as you can, and see what you can find. There will be patches 
of stranded seaweed, a few shells of dead clams, mussels, 
Fig. 37. Soft-Shell Clam. 
Specimen at bottom. Long siphon 
extending from clam to water 
above. (Photograph of Model. 
Courtesy of American Museum of 
Natural History.) THE OYSTER 
75 
and snails, and many other cast-up treasures of the sea. 
But as you walk along, small “geysers” of water will shoot 
up here and there, and after the geysers holes will remain 
to show where something happened. It will require more 
than a child’s spade to dig and find out. But in a little while 
you will reach a wrinkled, black object that will prove to be 
the siphon of a soft-shell clam. 
A soft-shell clam can move, but seldom does move, from 
its place in the mud, which is frequently as much as one foot 
from the surface. The siphon, however, stretches the whole 
distance from the shell and body proper, and draws in the 
food and air, and through an adjacent opening permits the 
wastes to pass out. When you disturb a clam of this kind 
at low tide, the siphon contracts, thus reducing the space 
within the valves, sending the water through the siphon with 
considerable force. 
The soft-shell clam has organs very much like those of 
the fresh-water mussel, except for slight differences in form. 
The mantle is grown together into a continuous fold except 
where there is a small opening for the foot. The shell is 
almost white in color and rather thin and somewhat 
flat. 
The young attach themselves to grains of sand until they 
are large enough to make holes and live under the same con- 
ditions as their adult relatives. 
The Oyster. Apparently the flavor of the oyster when 
stewed or fried is what gives to this bivalve its money value. 
The total of all plates of oysters and all bowls of clam chowder 
may be expressed in great sums of money. But neither ani- 
mal in reality is important as a food for human beings. One 
of the great problems met in trying to teach economy in our 
national habits of eating, is the difficulty experienced in some 
large cities in persuading persons to substitute nutritious, 
inexpensive food for highly flavored, expensive food. Oys- 76 
MUSSELS AND THEIR KIN 
ters are one of the least nutritious, and one of the most ex- 
pensive, of all our foods. 
Although the mussel and the clam bury themselves in 
the mud, they maintain connection through the siphon with 
the water outside. The oyster cannot endure lying in the 
mud, because it has nothing that can act as a siphon. More- 
over, if its body should be accidentally covered with mud, it 
could not escape as could the other two animals, because 
its body is connected inseparably by the left valve to other 
shells, or to a rock. 
Fig. 38. Oyster. 
(From Linville and Kelly: General Zoology; Ginn and Company.) 
Within the valves of the oyster, the mantle-folds, the 
gills, the mouth and the tentacles, are all very much the 
same as these organs are in its relatives. Since the adult 
oyster has a fixed position, the absence of a foot is a perfectly 
natural fact. 
As you know, there is a season in which it is not possible 
to obtain oysters in the markets. This is the time when the 
eggs and spermatozoa are being sent out upon the water, 
and the formation of oyster embryos is taking place. The 
number of embryos formed by the fertilization of the eggs SNAILS 
77 
is exceedingly great, but countless thousands lose their 
lives as they float about at the surface of the ocean for the 
first few days of their existence. Those that escape extinc- 
tion sink to the bottom and affix the left valve of the shell 
to some solid object. 
Each year they add to the size of the shell and the body 
until they are ready for the market. In order to make 
oysters especially valuable, they are sometimes taken up 
from their homes in bay or sound, and placed where the water 
is somewhat brackish, owing to the mixing of sea water with 
fresh water. Here many microscopic organisms abound. 
The fattening of the oysters on these organisms gives them 
finer flavor. 
Snails. In the ocean from the shore line out to con- 
siderable depths, on the land from valleys to mountain tops, 
in brooks, rivers, and lakes, ther< 
are snails of one species or an 
other to be found. Their num 
bers are legion, and their shape; 
many. Their architecture am 
their colors are attractive in th< 
extreme. 
All snails agree, however, ir 
having a flattened foot upon whicl 
they move, and most of then 
have a shell of one piece, with om 
or more spiral turns in it. Thej 
also have in the mouth a tongue 
provided with a rasping orgar 
which is capable of tearing into small particles whatever 
food they need. 
The surface of the body gives off large quantities of slime, 
upon which the foot slides in locomotion. The slime is also 
exuded as a means of protection when they are attacked. 
Fig. 39. Land Snail. 
Photograph taken at night. 78 
MUSSELS AND THEIR KIN 
Many snails, even water snails, breathe by means of a 
lung, which opens to the exterior by a single opening on the 
right side of the body. With this lung they breathe at the 
surface of the water and in the air. Some of the snails have 
gills with which they breathe in the water. 
Unlike their bivalve relatives, snails have a distinct head 
which is provided sometimes with one pair, sometimes 
with two pairs, of tentacle-like organs. In case two pairs 
are present, there will be found on the tips of the second 
pair two little black eyes, which can be extended and drawn 
in with facility. When but a single pair of tentacles is pres- 
ent, the eyes lie on top of the head. 
Everyone who keeps an aquarium should be aware of 
the fact that snails are good scavengers for aquaria. The 
little black or brown snails can be found easily in almost 
any pond. They would consider it a special favor to be 
protected from frogs and large fishes by being allowed to 
keep clean the water-ways of a goldfish aquarium. They 
feed on the green scum that frequently forms on the interior 
of the aquarium. 
Those who keep greenhouses feel differently toward 
snails, and especially toward their shell-less relatives, the 
slugs. But in nature there are so many checks and balances 
that it is the business-like thing to do to look for the enemy 
of any species that is getting more than its share of the 
earth’s products. The once despised toad will help you out 
of your troubles, if you have troubles of this kind. 
It may be worth your while to know also that the little 
masses of round, light-colored bodies from the size of radish 
seeds to the size of sweet pea seeds, the largest of them look- 
ing like small lumps of boiled tapioca, are the eggs of differ- 
ent species of slugs. Pond snails lay their eggs in small oval 
masses flat against the surface of the glass if they are in an 
aquarium, and on leaves and sticks, if they are in a pond. The 
eggs of sea snails are laid in masses of many curious shapes. THE SQUID 
79 
The French people consider snails a great delicacy for the 
table. That other people do not, may be thought at least 
by the French as one of the vagaries of taste. We need 
not forget that among the French are to be found the world’s 
foremost authorities in matters of cooking. 
The Squid. If you have not lost that natural curiosity 
mentioned in Chapter I, you must have wondered at the 
nature of che hard, white and oval object at which you have 
seen canary birds pecking. This white object is all there is 
of the skeleton of a cuttlefish, a close relative of the squid. 
This skeleton lies within the tissue of the main part of the 
body just behind the head. The squid (in Fig. 9 at right) 
has a thin, horny skeleton of no particular value to man. 
But all cuttlefishes and squids produce something of value 
in the black fluid from which India ink is prepared. The 
ink is also valuable to the animals themselves, because of 
their ability to force it out of the body into the water when 
they are being attacked by stronger enemies, thus setting 
up before them an impenetrable black curtain. In the 
cavity of the cigar-shaped part of the body extending to the 
exterior there is a siphon force-pump, with which the squid 
shoots out the ink and also water strongly enough to carry 
the owner backward out of danger. 
The squids and their immediate relatives live only in the 
waters of the ocean. They feed upon small fishes, and are 
themselves fed upon by larger fishes, if the fishes are quick 
enough to capture them before the black curtain comes down. 
The ten arms are provided with two rows of sucker-disks, 
extending the entire length of one side. The prey when 
brought to the mouth is seized in the parrot-like beak. Large 
eyes are present on the sides of the head. 
Other relatives beside the cuttlefish are the Octopus and 
the Chambered Nautilus. The latter has been made famous 
in the well-known poem by Dr. Oliver Wendell Holmes. 80 
MUSSELS AND THEIR KIN 
Summary of Mollusca. The mussels, the clams, the 
oysters, the snails, and the squids, and the near relatives 
of all of them, are members of the Branch called Mollusca. 
The word means “soft,” and applies especially to the char- 
acter of the body proper. Although we might question the 
value of the word soft on the ground that it might apply 
equally well to other animals not in the Branch, yet we must 
admit that softness and lack of apparant organization is 
peculiar to those members of this Branch that we are famil- 
iar with. 
The appendages of every member of the Branch are with- 
out joints, and the bodies have no segments or somites. 
The snails and the squids have a fairly distinct head, but 
the others have no head at all. Those that have heads have 
a pair of eyes, but in the others eyes are commonly absent. 
Locomotion is accomplished in practically all except the 
squid group by a single muscular organ under the body 
called the foot. This organ operates on a bed of slime which 
is sent out in front from numerous glands. 
All members of the Branch have a chin enveloping organ 
of one or two parts called the mantle. The chief work of 
this organ is the formation of the shell. The shell is present 
in two parts, in clams, in one part, in snails, and as a con- 
cealed plate, in squids. 
Mouth-parcs when present at all, occur as a rasping organ, 
in snails, or as a parrot-like beak, in squids. Around the 
mouth in clams and their near kindred there are four un- 
jointed, flat organs that wave inward and carry food to the 
mouth. The squid has ten long arms provided with flat 
suckers all adjusted to bringing prey to the mouth. 
Most of the members of the Branch breathe by means of 
flat, thin gills that lie on either side of the body floating 
out into the water inclosed by the shell. Some of the snails 
breathe by a lung to which a single external opening enters 
directly. CHAPTER IX 
THE FISHES 
The Sunfish. After you have been busy at the bank 
of the creek an hour or more with shiners, or chubs, or bull- 
heads, you are in a proper frame of mind to really appreciate 
a gorgeously colored sunfish, be it ever so little. There 
are few persons so devoid of a love of color as to fail to ad- 
mire these little fishes, with sides spotted over with all the 
colors sunlight contains. 
Sunfishes are nearly everywhere in the fresh waters of our 
country, in lake, river, and brook. They like the compan- 
ionship of their own kind, for they go about in “schools.” 
Their attitude toward the fisherman’s bait is to “stand and 
wait,” while members of more aggressive species take the 
hook, and are drawn up on the bank. But when they are 
very hungry, even earthworm bait is sufficient to induce them 
to try their luck at the white man’s game. 
Sunfishes never get very large. You might work with 
your line a long time and never see one longer than six 
inches, although some species of sunfishes do reach the 
length of twelve inches. Their bodies are flattened from side 
to side or “compressed.” This gives them the appearance of 
being very slender when seen from above in the water. 
Like all fishes the sunfish swims nearly altogether with 
its tail fin. The other fins, the back or dorsal fin, and the 
anal fin which is beneath the body, and the two pairs of 
fins—all aid the fish in balancing, and to some extent in turn- 
ing. 
One of the most characteristic details of the coloring of 
the sunfish is the blue, or red, or black, conspicuous spot 
81 82 
THE FISHES 
just above the front or pectoral pair of fins, at the end of 
what is called the gill-cover. These gill-covers open and 
close periodically, permitting currents of water to come out 
from the mouth cavity. 
If you notice a fish resting in the water of the brook, or 
in the aquarium, the opening and closing of the gill-covers 
seem to be connected with certain movements of the mouth. 
The water is filled with air, or at least as much as can find 
room between the molecules of water. When a mouthful 
Fig. 40. Sunfish. 
(From Goode: American Fishes.) 
of water goes in, the red, blood-filled gills absorb the oxygen, 
and at the same time permit another gas which is a waste 
of the body to pass outward. This waste comes out into 
the water from beneath the gill-covers. 
The oxygen that is taken into the blood flows back into 
blood vessels extending through the body. Atoms of oxy- 
gen come into contact with atoms of carbon in stored food 
in the muscles of the fish, especially in those muscles which 
do the most work. The combination of these atoms forms 
carbon dioxide. This compound passes as a gas into the THE EEL 
83 
blood, and after going through the heart and into the gills, 
it is expelled there with the water. 
The process by which oxygen combines with another ele- 
ment is called oxidation. A very important manifestation 
of oxidation is the setting free of a certain amount of energy. 
This may be either in the form of actual work done by the 
muscles, or of heat. 
The breathing of the fish is merely an exchange of gases 
through the delicate membrane of the gills. That is all 
that really takes place in breathing in our own bodies. 
Fishes can smell, as you must have thought when you have 
seen them swimming up and “ nosing ” your bait, and turn- 
ing away from it with apparently unconcealed contempt. 
Their nostrils are two small openings just above the upper 
lip. The nostrils do not extend into the mouth opening as 
ours do, but nerves connect the cavities with the brain. 
It is the nerve connections with the smelling organ that en- 
able the fish to smell, and to know that it is smelling, and 
sometimes what it is smelling. 
The eyes of fishes are movable, but they are without 
lids. They have ears, but they are internal. The waves of 
sound reach the ears by going through the bones of the skull. 
The Eel. There are person who will have nothing 
to do with eels because they believe they are snakes. People 
of that kind are of course prejudiced against snakes. But 
an eel is just as much a fish as a sunfish is one. Moreover, 
eels are a mysterious kind of fish only because of the fact 
that it was as late as the close of the last century that the 
reproduction became known. From the time of the Greeks, 
learned men have believed impossible tales of the origin of 
eels, among others that eels develop from the slime of the 
sea. 
We now know that when eels are full grown they swim 
down the rivers to the sea. At the mouths of the rivers the 84 
THE FISHES 
females lay their eggs, and the males spread their “milt” or 
spermatozoa over the eggs as is done by other fishes. Both 
male and female eels then die. The young hatch from the 
eggs in a few weeks, and soon begin their instinctive travel- 
ing upstream. Until the young reach adult size, which is 
about two or three feet, they live constantly in fresh water. 
Eels feed voraciously on other fishes, and also on dead 
animal matter. They are said to be a nuisance in rivers 
where shad are caught in nets. In the confined area of the 
Fig. 41. Eel. 
(From Goode: American Fishes.) 
net, they can easily reach their prey, and consume large 
quantities of them in a short time. 
The characteristics of structure which ally the eels to the 
fishes are the possession of gills and fins. Unlike most other 
fishes they are without scales, having a perfectly smooth 
skin. 
Sharks. There are sharks of only two feet in length, 
and there are giants of forty-five feet. The little ones are 
called dogfishes, and are nuisances to the fishermen of the 
North Atlantic coast. The largest are called the Basking 
Sharks. There is but one species of shark that is known to 
be sometimes dangerous to man, and the living specimens 
of this one, the great white shark, are very rare. THE CODFISH 
85 
In general appearance the shark is a fish with a very slen- 
der body, and a pointed head with the mouth beneath the 
head. The crescent-shaped mouth has rows of very sharp, 
triangular teeth. The region of the gills has five slits open- 
ing directly to the exterior. There are no gill covers. The 
skin of the shark is covered with sharp, hard scales, so closely 
placed that the skin is sometimes used for polishing wood. 
Fig. 42. Blue Shark. 
(Model. Courtesy of American Museum of Natural History.) 
It is called “shagreen.” The tail in sharks has the upper 
lobe longer than the lower one. 
Sharks are among the strongest and the most ferocious 
inhabitants of the sea. Ordinarily, their food consists of 
small, more or less defenseless animals, such as small fishes, 
squids, crabs, and lobsters, but they have been known to 
attack, and to carry on a battle royal with swordfishes. 
The Codfish. If you happen to know anyone living in 
far away Newr Foundland, or in Nova Scotia, or if you happen 
to live in either province yourself, you probably are aware 
of the fact that catching codfishes is not surrounded with 86 
THE FISHES 
any of the atmosphere of the holiday that yon may have 
felt in catching sunfishes. Everything connected with catch- 
ing codfishes means work, hard work, dirty, slimy work, and 
dangerous work. 
If you should watch the best-equipped outfits as they are 
preparing to leave port, you would see the men loading the 
small fishing steamer with provisions for a voyage of sev- 
eral weeks on the Grand Banks of New Foundland, a great 
stretch of ocean where the 
water is not as deep as it is 
farther out, and not as shal- 
low as it is near the land. 
The men are also putting in 
a supply of squids (seeFig. 9) 
on ice for bait. There are 
many tubs on deck filled 
with thousands of feet of 
fishing line, coiled around 
and bearing at intervals pen- 
dent lines and hooks. 
Swinging from the davits 
are the dories, the fishing 
boats, in which the men go 
out when they reach the Banks. 
The equipment for a dory is two pairs of oars, two buoys 
or floats, tubs of line with baited hooks, and food and water 
for several days. The boats scatter in different directions 
from the steamer, and when they have rowed a sufficient 
distance, one end of the line is attached to a buoy, the buoy 
anchored, and the line “paid out” until the other end of it 
is reached, when the other buoy is attached and anchored. 
Thus the trawl is set and left with signals by which the men 
may find the line when they return the same day or the next 
day. Then the men row further and set another trawl, and 
another, until their work of setting is complete. 
A large specimen just released from 
net. Photographed on board ship. 
(From Codfishing in the Atlan- 
tic, Courtesy Beselar Educational 
Film Co.) 
Fig. 43. Codfish. THE CODFISH 
87 
On returning to the trawls, the men begin to take up the 
line at one end. When they reach the drop lines, they draw 
them up, remove any fish, rebait the hooks and let them fall 
again. 
All this is hard work and little fun, because the cod is not 
a game fish in the sense that he may lead one a merry chase 
Fig. 44. Scene of Codfishing. 
Fish net being opened, and huge catch pouring out on deck of 
fishing steamer. (From Codfishing in the Atlantic. Courtesy 
of Beselar Educational Film Company.) 
over the briny deep. Sometimes when the men are busy, 
a storm comes up, or a fog settles upon them. It is not un- 
common for men under these circumstances to lose their 
way and starve, or to be wrecked. When the cleaning, salt- 
ing and packing is done, the steamer or sailing vessel returns 
to port, sometimes with signals set at “man lost.” 
Several hundred sailing and steam vessels and several 
thousand poorly paid men of this country and Canada are 88 
THE FISHES 
employed in the industry of codfishing. The product is ex- 
tremely valuable, and has been made the occasion for exact 
treaty regulations between the two countries. 
Codfishes live near the bottom in water from twenty 
to seventy fathoms. They migrate from New Foundland 
and Labrador south as far as Virginia, but are not captured 
in large quantities farther south than New England. In size 
codfishes vary from seventy-five pounds down. Naturally, 
the longer the fishing industry continues at its present rate 
of capture, the smaller will be the size of the fishes captured. 
However, the governments are propagating the young arti- 
ficially, and rearing them to a sufficient size before letting 
them go into the sea again. The results of this artificial 
propagation are very satisfactory. 
In Labrador the families of the fishermen live in great 
poverty, with few of the joys of life that go with existence 
for most of us in our own country. In this connection, you 
may find the opportunity to read what Dr. Grenfell, an 
English physician, has done in helping our fellowmen in the 
frozen Northland. 
(From Goode: American Fishes.) 
Fig. 45. Salmon. 
The Salmon. A little trip of three thousand miles 
across the continent brings us to the part of the country 
where salmon are worth fishing for, although the rivers of THE SALMON 
89 
Eastern Canada and New England also contain salmon. 
The market value of the entire salmon cateh of our west 
coast including Alaska is said to be $13,000,000, annually. 
This makes the salmon of the Pacific coast the most valuable 
of all the fishes in the world. 
When fishes are caught, they fall victims to some trap 
that man lays for them. He studies their instincts, and 
makes his plans accordingly. In most cases fishes are caught 
because they need something to eat. However, fishes may be 
abundant in a given region at certain times and food corre- 
spondingly scarce, and they will pay no attention to human 
temptations. When, for example, the chinook salmon is 
making its way literally by the millions up from the mouth 
of some river in the spring, they are well fed, and apparently 
can live for days or weeks without eating. The instinct 
carrying them along steadily day after day is the instinct 
of reproduction. The females are carrying millions of eggs, 
and the males many millions of spermatozoa. 
The fishes swim along three or four miles a day until they 
arrive at the headwaters of some tributary where the water 
is comparatively shallow, and the bottom gravelly. The male 
digs a shallow “nest” in the gravel with his snout and tail. 
The female then deposits her eggs, and the male expels his 
milt over the eggs. The two cover the eggs with gravel, and 
soon afterward both die. When the eggs hatch the young 
make their way down to the sea, and live there until they 
in turn are mature. 
Except for some trawl and line fishing in the ocean, the 
great fishing for salmon is done when they are on their way 
up to the spawning beds. The arrangements that man has 
made for the capture of the fishes on their instinctive journey, 
seem almost diabolical, for he actually makes the fishes cap- 
ture themselves. 
Imagine the much enlarged reel of a reaper machine, 
which may require your having seen a reaper. Extend 90 
THE FISHES 
the radially placed blades of the reel down nearly to the 
supporting axle, and insert other blades between them. At 
the circumference, the radially placed partitions are about 
two feet apart, and near the axle, less than one foot apart. 
The length of the reel is perhaps about fifteen feet. It is 
supported horizontally from a supporting stage on the bank 
of the river, in such a way that the lower edge of the reel 
extends two feet or more 
into the water. Around 
the axle there is a con- 
siderable space in which 
is adjusted a trough that 
leads outward and down- 
ward to great low tables 
on the bank, or into a 
flat boat. 
When the reel is low- 
ered into the water the 
current sets it in motion. 
Now, the salmon swim- 
ming upward keep fairly 
close to the bank. When 
they swim into a segment 
of the reel, they find 
themselves lifted out of 
the water by a force 
greater than their own 
weight. When they ap- 
proach the highest point in the revolution, they slide down 
into the trough, and then outward by gravity to the pre- 
paring table. Before long they are in cans. 
The characteristic pink color of the flesh of the salmon is 
present only when the fishes are caught in the earlier portion 
of their journey. In a measure, the color is a measure of 
their vitality. However, the flesh from which the pink 
Fig. 46. Scene of Salmon Fishing. 
A fish trap on Columbia River; different 
construction from trap described in text, 
but operated by current. (Photograph 
by J. T. Nichols for American Museum 
of Natural History.) SUMMARY OF FISHES 
91 
has faded out partially is not less palatable to an appreci- 
able extent. Nevertheless, it is not marketable and is 
thrown away. Thus the enormous capture is attended with 
very great loss, both from waste and from the death of un- 
told millions of eggs, from which would have developed 
the young fishes. 
Summary of Fishes. ■— The fishes are the lowest of all 
the backbone animals, and constitute a fairly distinct group. 
Their structural characteristics are very definite. The body 
divisions are head, trunk, and tail. The head bears a pair 
of eyes, and two nostrils that are the seat of the sense 
of smell and are not connected with the breathing system. 
The mouth is provided with numerous teeth, and connects 
with the digestive system, as well as with the gill chambers 
at the sides of the head. 
The skin is filled with scales that overlap like the shingles 
on a house. Their arrangement and the presence of slime 
glands in the skin facilitate the passing of the body through 
the water. However, the pointed head, the heavy middle 
where are stored the numerous internal organs, and the 
long, flattened, muscular tail are all more important adjust- 
ments to life in the water and rapid progress through it. 
Fishes lay great numbers of eggs to which very few species 
of the Class are inclined to give any attention during the 
period of development. But those which do, like the sun- 
fishes and the sticklebacks, offer a basis of interest for human 
beings that suggest greater expectations as we go up the 
scale of animal life. CHAPTER X 
FROGS, TOADS, AND SALAMANDERS 
The Leopard Frog. Unless you live west of the Sierra 
Nevada Mountains, you are probably as familiar with the 
leopard frog as with any other,—possibly more so. For its 
gray skin with the two rows of irregular dark spots are con- 
spicuous enough to make a positive impression on one. If 
they have not impressed you, then the leopard-like leaps, 
valiant, strong, and ready, should have won your admiration. 
You are likely to come upon a leopard frog in a pond, or 
a spring, or in a meadow. They wander away from what is 
supposed to be the natural place of living of all frogs as far 
as fields and orchards. But their wandering is not the re- 
sult of aimless whim. Where their food goes, there the 
leopard frogs also must go. The grasshoppers themselves 
have some ability as jumpers, and frogs are fond of grass- 
hoppers. 
Far as a frog may go from water, it is in water after all 
that it belongs, for its soft, naked skin, only slightly supplied 
with slime glands must not become entirely dry. An exten- 
sive network of blood vessels covers the interior of the skin, 
and permits the oxygen to penetrate to the blood. The frog 
is adapted in other ways to life in the water. The strong 
athletic hind legs, although very effective on land are still 
more so in the water, on account of their having between the 
toes a thin web which may be stretched wide like a duck’s 
foot. When the hind legs are drawn up sharply, and shot 
out quickly, they send the animal darting further than it 
could possibly go at one leap on the land, besides carrying 
it safely under a lily pad, or into the concealing mud. 
92 TI1E LEOPARD FROG 
93 
Long have you waited expectant, perhaps, for a disappear- 
ing frog to come to the surface again. And when it did come 
up, you wondered at its ability “to hold its breath.” If 
the frog does not come to the surface immediately a few feet 
away, with its nose just behind a stick possibly, it may stay 
under several minutes, for the oxygen absorbed in the water 
will penetrate the skin and afford all the animal needs for 
the time being. 
When the frog arises again, it begins once more to “swal- 
low” its air, for that is what it must do. The air coming 
into and through the nostrils lies in the cavity of the mouth 
until it is forced down into the lungs by the contraction of 
the throat. This is an odd way of breathing, because or- 
dinarily air goes down into the lungs of animals because the 
chest-walls expand and give increased space for air to rush 
in to fill a forming vacuum. 
There are some other strange facts about the frog which 
appear especially interesting to us, because we are now get- 
ting near to types of animals that resemble man in some 
ways. The opportunity to make comparisons brings out 
the contrasts. For example, the frog can close its eyes, but 
how strange for the closing lid to come up from below like 
some of those window shades at school. It is also queer to 
see the eyes disappear into their sockets, when touched 
lightly. Where could they go but into the mouth? And the 
ears also make us think of that important part, the drum of 
our own ears, which receives the waves of sound and enable 
bony structures to carry them to the nerves within. 
But the frog is much behind man in ability to defend it- 
self. It has nothing at all to fight with. It must depend 
on seeing its enemy in time to jump and hide. Its ability 
to hide depends largely on the fact that its skin resembles 
to some extent the surroundings in which it lives. At least, 
the back and sides are quite inconspicuous against the mud 
and water of the frog’s home. In addition, the frog benefits 94 
FROGS, TOADS, AND SALAMANDERS 
by the fact that it is able to produce a great number of 
young. Otherwise this and many other species that also 
have numerous young would be exterminated. 
After the winter’s sleep in a burrow under a log, or in a 
crevice in the leaf-covered rocks, the male and female frogs 
go to the ponds in March or April. There the eggs are 
Fig. 47. Development of Leopard Frog. 
Young in different stages of transformation; swimming in shallow dish. 
(Photograph by the author.) 
laid by the female and fertilized by the male. The eggs are 
little black dots, resembling in size and color the head of a 
small black dressing pin, each one imbedded in a clear 
sphere of jelly larger than a pea. The mass of eggs, as much 
as you could hold in your hand, are fastened by the female 
to a submerged stick, which prevents the eggs from being 
carried away in chance currents of water. TOADS 
95 
In about ten days, the little “pin-heads” have changed 
to tiny tadpoles with tails and minute, fringed gills at the 
neck. Escaping from the egg-case, they fall to the bottom 
or cling to the egg-case for a while, because they have no 
mouth yet. During this time they live on the yolk of the 
egg which the mother has supplied. When the mouth forms, 
the tadpoles venture further, and begin to feed upon the 
slimy covering of submerged leaves, or on tender plants 
beneath the surface of the water. 
Their troubles begin immediately, for some of the vora- 
cious water insects which were the occasional food of the 
parents of the tadpoles now seize che little wriggling crea- 
tures as they pass, and soon thin their ranks. Fishes, 
too, prey upon them. But they are numerous and they grow 
rapidly. By July and August the tadpoles have formed 
hind legs, and soon afterward fore-legs appear. Then the 
tail begins to be drawn in, and it finally disappears. For a 
a day or two it is a very critical period for frogs, for the 
energy expended in making these extensive alterations in 
the anatomy leave them exhausted. But the young frogs 
can leave the water, and usually do leave the water, even 
before the anatomical changes are complete. Otherwise, 
the race of frogs might be exterminated by fishes. Only a 
little while, and the frogs are capable of leaving for the 
meadows and the orchards, where the grasshoppers live. 
Toads. The author of The Frog Booh, Miss Mary C. 
Dickerson, gives, incidental to an extremely interesting 
study of toads, a few paragraphs on their money value. She 
says, “It is found that 88% of a toad’s food consists of in- 
sects and other small creatures that are considered pests 
in the garden, grain field, or pasture. It is estimated that 
in three months a toad will eat 9,936 injurious insects, and 
that of this number 1,988 (16% of all its food) are cutworms. 
Counting the cutworms only, the estimated value of a single 96 
FROGS, TOADS, AND SALAMANDERS 
toad is $19.88, if the injury done by a single cutworm be 
put at llie low figure of one cent per year.” 
It is of course very unfair to the toads to leave the matter 
there, for with a far higher and a more exact estimate of the 
money their presence saves us, our treatment of them would 
probably be more considerate. If everyone knew about 
this feature of the toad’s career, we would respect their 
welfare more than we do, although we might not feel like 
paying for one even a fraction of its economic value. But 
in France gardeners would 
pay you well for toads. 
There the people gener- 
ally make more use of 
their resources than we 
do in America. One 
American author, Pro- 
fessor Hodge, of Reed 
College, Oregon, suggests 
that we make of the toad 
a domestic animal, and 
care for it as we do other 
domestic animals. At 
first, the suggestion strikes us as being amusing, but the 
toad all unconscious of our amusement, goes on increasing 
the store of our national wealth an incalculable amount. 
The fact that a toad’s skin is warty will not lead to your 
skin becoming warty from handling the toad. One fact has 
nothing, or can have nothing, to do with the other. Neither 
is the toad poisonous, except to certain animals that seize 
and try to swallow it. When necessary for its own defense 
against devouring creatures, the toad exudes from a pair of 
glands behind the ears an extremely irritating fluid, which 
seriously annoys every creature that preys upon the toad, ex- 
cept snakes and skunks. The ordinary handling of toads by 
human beings does not result in annoyance either to the 
Fig. 48. Toad. 
(From Dickerson: Nature Library; Double- 
day, Page and Company.) TOADS 
97 
toads or to the persons. Ordinarily, the skin of the toad is 
dry, and entirely agreeable to the touch. 
It is true that the toad is “dumpy” in appearance and 
generally unattractive looking, but its very appearance is 
one of the important reasons the species is with us to-day. 
The dusty color and the warty back serve to render them 
inconspicuous as they lie in their shallow pits during the 
daytime. Unless you should actually touch one at such a 
time, or frighten it and make it jump, 
you would scarcely notice it at all, and 
neither would snakes, another heartless 
enemy of toads. 
About dusk and as long as there is 
light, and in the early morning, toads 
take their chances, and go abroad in 
search of food. As their squat figures 
hop along, it would seem that a lively 
insect would be stupid indeed if it per- 
mitted the toad to catch it napping. 
But the insects do not know until it is 
too late that the really dangerous part 
of the toad is its tongue. If you see 
a toad’s nose within two inches of a 
house-fly, you may suddenly realize that 
the fly is no longer there. This is be- 
cause the toad’s tongue with its sticky 
surface is capable of being thrust out so 
quickly, and withdrawn again, that one 
cannot even be sure he has seen the 
tongue. The fact that the tongue is 
fastened to the lower jaw at the front 
makes a long reach possible. For in- 
sects that are further away than two inches the toad makes 
a swift little spring, and all is over as before. 
Everything is business with the toad—the business of get- 
Fig. 49. Eggs of Toad. 
Strings of eggs in gel- 
atinous case en- 
tangled in water 
plant. (From Dick- 
erson: Nature Li- 
brary; Doubleday, 
Page and Company.) 98 
FROGS, TOADS, AND SALAMANDERS 
ting enough to eat—and it keeps steadily at its business as 
long as it can see at night, and in the daytime while the sun 
is not too drying on its skin. When cold weather comes 
it hides away in burrows, or under leaves and logs, becom- 
ing very cold but not freezing. 
In the spring, the warm days take the chill from their 
benumbed bodies, and they come out. Immediately all the 
toads, males and females alike, go to the ponds where we 
may hear the males making their trilling whistle when there 
are few other signs of spring. In a few days, all the females 
have laid their eggs in long, jelly-ribbons, and have left 
them in the water. From the eggs of one female, 7,000 to 
12,000 young will emerge in four days. One of the familiar 
sights of the margin of almost any pond in May and June 
is thousands of tiny black polliwogs feeding on the scum 
of submerged leaves. Shortly afterward the tadpoles have 
changed to toads very much as frog tadpoles change to 
adult frogs, but much more quickly. 
When the young toads leave the water, they hide in the 
daytime, and come out at night or during a rain. Some- 
times they seem to come down with the rain. But that is 
another myth. 
The Salamander. At the margin of the lily pads, where 
the pickerel ought to be, something will draw down your 
float feebly, and with some misgiving you will lift your line 
and find clinging to the bait one of the many hundred sala- 
manders or newts to be seen swimming lazily about the 
boat. They are nuisances under the circumstances, but 
independent of the particular circumstances they have 
their own features of attractiveness. 
Examined in your hand, a newt shows at once that its 
mode of life must be quite different from fishes. In the 
water it swims slowly along with its flattened tail waving 
from side to side. The four legs lie idle at the sides. Once THE SALAMANDER 
99 
in a while it comes to the surface, for it is an air-breather. 
After it has gobbled a mouthful of air, it goes back and 
swims about for a while, before it needs to return to the 
surface. 
These newts are about three and one-half inches in length. 
They are olive green above with a row of orange-colored 
circular spots along either side the middle of the back. The 
under surface is yellow with black dots. 
All the newts found in this stage in the water are at least 
Floating in water. (Photograph. Courtesy of American Museum of 
Natural History.) 
Fig. 50. Salamander. 
three years old. Their preliminary career is interesting. 
In early spring the females lay their eggs singly in the axils 
of the leaves of certain water plants, and inclose them in 
the branches, sealing all together with sticky slime from 
the egg glands. Little slender tadpoles with fringed gills 
emerge and grow larger through the spring, and until 
August. In the meantime, four tiny legs come out at the 
proper places, and are used by the tadpoles in crawling 
over submerged rocks in the brooks and pools. In the 
autumn of their first year they develop lungs in place of 
gills, and leave the water to live on the land. For the next 
two or more years one may see them in a Vermillion skin, 100 
FROGS, TOADS, AND SALAMANDERS 
bearing a rounded tail. After a rain while the air is still 
damp, they come out in large numbers, looking for insects. 
In the third or later year of their existence the skin 
changes to the olive-green of the adult, the tail becomes 
compressed, and they take up the final stage of life in the 
water. 
The salamander just described lives in the eastern United 
States. In the state of New York and westward to the 
Mississippi Valley there is a species of salamander, called 
the mud puppy, technically known among zoologists as 
Necturus. It is eight to twelve inches long, mottled black in 
color, and bears external gills throughout life. It also has 
lungs. 
Summary of Amphibia. The Class Amphibia is called 
by that name because the members of the Class all “live 
both” in water and on land. Frogs, toads, and salamanders 
have not only this characteristic, but also several others in 
common. For example, the young are hatched from eggs 
in ponds and brooks, with a pair of feather-like gills grow- 
ing just behind the head. The external gills in most species 
give place to internal gills, and finally to lungs. While bear- 
ing gills, the animals must live in the water; on the land they 
may have lungs. This fact gives the habit basis for the 
Class name. 
At one time or another, all the members of the Class have 
head, trunk, and tail. The adult forms of frogs and toads 
also have tails, but the organ is not visible, on account of 
the tail bone being withdrawn into the body. The skin of 
the body is without scales, being very smooth. In some 
species the skin is very thin, and is supplied with blood- 
vessels into which oxygen easily passes from the air. Glands 
that produce slime keep the skin from becoming dry, and 
in some species protect the animals against capture by the 
acrid nature of the secretion. SUMMARY OF AMPHIBIA 
101 
Typical external organs are four legs with eighteen toes 
in all. All have two eyes with eyelids, nostrils that connect 
with the lungs through the mouth cavity, and in frogs and 
toads ears that have the drum as an external part. The 
mouth is provided with teeth for holding prey. CHAPTER XI 
SNAKES AND OTHER REPTILES 
The Blacksnake. Perhaps if you got a blacksnake or 
a blue racer “in a corner” it would show fight. Of course 
it would not give a person a comfortable feeling to be jumped 
at by four feet of black, nervous wrath, notwithstanding 
one knows the animal is less harmful than a mosquito. And 
if you had not been trained all your lives to fear what has 
been feared by all the generations of human beings before 
you, a snake might even appear to be a creature with some 
rights of its own. 
In fact, even when the blacksnake is in its “corner” you 
can see that it is afraid you will do it harm—and you probably 
would. The author once came suddenly upon a blacksnake 
nearly five feet in length. It started to run toward him, 
striking with its head, and nervously waving its tail in rapid 
vibration, causing the grass to play a crackling tune. True 
to an age-long education, the author walked away as rapidly 
as seemed necessary, whereupon the snake turned and made 
off with amazing swiftness. The blacksnake is really and 
truly a “racer”. 
Most observers do not make positive recommendations 
regarding our proper altitude toward blacksnakes. It is 
generally acknowledged that they destroy a great many 
birds’ eggs and nestling birds, but they also capture and con- 
sume field mice and moles. Independent of the important 
matter of percentages of good and evil done by these snakes, 
it nevertheless should appear that any song birds destroyed 
would be a large price to pay for even a large number of 
field mice destroyed. A reduction in the number of black- 
102 THE BLACKSNAKE 
103 
snakes might help to solve the great problem of saving the 
song birds for our fellow citizens of the next, and the next, 
generations. 
The examination of the under surface of any snake reveals 
a single series of narrow, transverse plates, the front edge 
of each overlapped by the hinder edge of the one in front. 
This provides the snake with numerous sharp-edged plates 
which can be set partly on edge by muscles which control 
Fig. 51. Blacksnake. 
(Photograph. Courtesy of American Museum of Natural History.) 
them from within. By the rapid working of these muscles 
against the grass, the snakes get along very well without 
legs. 
The body of all snakes is covered with overlapping dry 
scales. Snakes breathe by means of lungs from the time 
they are born. Their eyes are not provided with lids. The 
tongue is forked, and in fear is extended and withdrawn 
with great rapidity, being used chiefly as an organ of touch. 
One of the baseless “snake stories” is that they “sting” 
with the forked tongue. Such a thing is not possible. 104 
SNAKES AND OTHER REPTILES 
Some snakes lay eggs which hatch in protected places in 
the heat of the sun; others bring forth their young alive. 
But in the latter cases the eggs are first developed to hatch- 
ing in the body of the female. 
The Rattlesnake. The rattlesnake is one of the few poison- 
ous snakes in America, and everyone of its dozen species 
is becoming exterminated rapidly. Even when they were 
numerous, it was a rare occurrence for a person to be bitten 
by one. 
When we hear a dangerous animal mentioned, most of 
Fig. 52. Rattlesnake. (From Linville and Kelly: 
General Zoology; Ginn and Company.) 
us have at least a momentary feeling of fear, forgetting that 
man himself is the most dangerous of all the animals. When 
the need arises, he can and usually does overcome his enemy 
of a lower race. All the lower animals that have some of 
man’s intelligence realize this instinctively, or learn it by 
bitter experience. The rattlesnake always tries to get away, 
but if it cannot, it coils, shakes its tail just as the black- 
snake does in its excitement, and strikes with its mouth open. THE RATTLESNAKE 
105 
The rattle, which is composed of the terminal unshed 
remnants of numerous moltings of skin, acts through its 
vibrations as a warning. There is no reason to suppose that 
this snake desires to warn its enemy. That would be ascrib- 
ing to a non-thinking animal more thought of consideration 
Above, bones of head with teeth and fangs; 
middle, showing position of fangs and poison 
glands; below, poison gland, with reserve 
fangs. (From Linville and Kelly: General 
Zoology; Ginn and Company.) 
Fig. 53. Mouth of Rattlesnake 
than human beings would show. The snake is merely ex- 
cited, and the rattling is an incident to that excitement. 
Fortunately, man and other animals profit by it, but it is 
doubtful if rattlesnakes do. Naturally, it would lead to 106 
SNAKES AND OTHER REPTILES 
their destruction by man. Deer kill snakes by stamping 
on them, as do other large animals. 
The mouth of the rattlesnake is provided with small 
teeth around the upper and lower jaws, and also with two 
poison fangs, bent scimeter-shape somewhat like the claw 
of a cat, and lying sheathed in the roof of the mouth. Near 
the tip of each fang is a small opening connected with a fine 
tube which leads to the poison glands back of each eye. 
When the fangs strike the victim, the pressure upon the 
glands forces the poison down the tube into the wound. The 
poison of the rattlesnake is fatal unless counteracted by 
medical treatment, in which permanganate of potassium 
and liquid strychnine are the principal factors. This treat- 
ment would apply in any poisonous snake bite. But let 
us not worry, for no more than two persons of the hundred 
millions in our country die from snake bites each year. 
The Box Turtle or Tortoise. Some time when you are 
not expecting it, you may be startled by the scrambling of 
a box turtle or tortoise in a pile of brush lying in the field. 
Or you may stumble upon one in the woods, and hear the 
sinking hiss made by the animal in drawing its head back 
into safety in its box. 
Box turtles wander about slowly in the woods and fields, 
and are found throughout the greater part of our country. 
They are among the oddest of animals. Perhaps they would 
seem more so, if we read about them as living in some little 
explored country. 
When the turtle withdraws into its shell, the lower section 
of the shell, called the plastront closes at the front protect- 
ing the head, and at the back protecting the tail. The 
closing is accomplished by muscles working on a hinge across 
the plastron. The upper section of the shell, called the 
carapace, is made up of plates of hard, horny material which 
enlarge around the margin of each as the animal grows and THE BOX TURTLE OR TORTOISE 
107 
requires more space. No animal but man can possibly in- 
jure the turtle when it has closed its shell. 
The shell of the turtle is considered by some casually as 
the skeleton, but the true skeleton is inside the cavity. The 
backbone lies along the middle line of the carapace, and the 
other main parts of the skeleton hinge to the backbone. The 
shell is nothing but an outer skeleton, corresponding roughly 
to the skin of other animals. 
Turtles live largely upon the larvae of insects, and upon 
(From Linville and Kelly: General Zoology; Ginn and Company.) 
Fig. 54. Box Turtle or Tortoise. 
earthworms and slugs. Turtles seem to come into slight 
relation to human beings, and for that reason we commonly 
have no fear of them. For this they should be grateful. 
Young turtles are hatched from eggs, which are laid by 
the females under leaves, or in the soft earth. When winter 
comes, the turtle burrows a foot or more into soft earth, 
and there hibernates. 
The American Chameleon. About the year 1893 it 
was a passing fashion for ladies to “wear” living chameleons. 
These tiny lizards were fastened with a gold collar and chain, 108 
SNAKES AND OTHER REPTILES 
and allowed to clamber about the shoulders of their owners. 
Since that time, many persons really interested in these 
color-changing lizards have kept them as pets, but with 
greater feeling for their animal rights. 
The chameleon is about seven inches in length. Its body 
is covered with small overlapping scales. The four legs are 
slender and strong, and the toes are provided with adhesive 
pads enabling it to run up smooth, vertical surfaces. It is 
Fig. 55. Chameleon. 
(Courtesy of American Museum of Natural History.) 
found in this country in the coast region from North Carolina 
to Texas, where it lives in trees, and feeds on insects. 
This lizard possesses to a remarkable degree a quality 
that is characteristic in some measure of several species of 
lizards in this country. Mr. R. L. Ditmars, in The Reptile 
Book gives a full and very interesting account of the color- 
changing ability of the chameleon. While sleeping, it is 
pale green above and clear white beneath. When badly 
frightened, it becomes green all over. During normal con- 
ditions in the early morning, and in the late afternoon the 
colors are slaty or yellowish. Often in the brightest sunlight 
the color is a dark, rich brown. The change of color is 
brought about principally through temperature and light, 
and by anger, fear and sleep. Surrounding colors in vegeta- THE ALLIGATOR 
109 
tion and elsewhere have no influence upon the occurrence of 
these colors, but doubtless there is considerable advantage 
to the animal in a green color during sleep as well as while 
it is being attacked by an enemy among the leaves of a 
tree. 
Changes in color are under the control of nerves which 
contract and expand masses of color pigment in the skin 
beneath the scales. These nerves can bring about a striking 
change from one color to another within three minutes. 
Mr. Ditmars recommends to persons who keep cha- 
meleons as pets that special care should be taken to sprinkle 
their box or cage inside with water, or better, to sprinkle 
leaves in the cage with water, since their own method of 
getting a drink is to lap one from the dew on leaves. They 
will capture flies for themselves about the room, or will 
take mealworms which are easily raised in the winter months 
when flies are not to be found. They will eat cockroaches 
too, which may make the presence of the lizards extremely 
welcome. 
The Alligator.- In the early geological days of our 
country, many millions of years ago, there lived a great many 
kinds of giant reptiles. They and their descendants passed 
out of existence long before man appeared upon the earth. 
The alligator, familiar to many of us from visits to zoological 
gardens, seems to us like a giant. And it is the largest of all 
that are left. However, the collection of a good museum 
that contains the fossils of extinct monsters would make the 
alligator appear small indeed. 
Alligators sometimes reach the length of twelve feet and 
the weight of over five hundred pounds. Large ones may 
be found only in the wild swamps of the southeastern coast 
states. Even there they are being rapidly exterminated by 
hunters who desire their skins for the leather market. The 
eggs are taken from the conspicuous nests of sticks and leaves 110 
SNAKES AND OTHER REPTILES 
and are sold to be eaten. Curio hunters buy from dealers in 
the South little alligators which they cannot raise, thus fur- 
ther tending to annihilate a species which is of great value. 
Although alligators are credited with being dangerous to 
man, they really are afraid of him, and will try to escape 
whenever escape is possible. However, when they are cor- 
nered or wounded and prevented from reaching their native 
element, the water, they will attack a man. With their 
powerful tail, they can knock a man down, and with their 
(From Linville and Kelly: General Zoology; Ginn and Company.) 
Fig. 56. Alligator. 
strong and merciless jaws and teeth, they would prove dan- 
gerous in the extreme. 
In the water, alligators dive and remain out of sight when 
danger threatens, or when stealing upon a swimming bird 
which they want to capture. They drag their prey be- 
neath the surface and drown it, but they must come to the 
surface to swallow it, in order to avoid strangling when the 
valve to their own lungs is opened. When they are not 
seeking food or escaping enemies, they spend much time 
basking in the sun on the banks of streams and lakes. 
With the plentiful supply of food that these regions af- 
ford, and the hot moist air of the banks, it is small wonder SUMMARY OF REPTILES 
111 
that the alligators contract the habit of sleeping long hours, 
and growing witn great rapidity. 
Summary of Reptiles. The Class Reptilia comprises 
animals of still higher development than the Amphibia. 
Some of the members of the Class live both in the water and 
on the land, but none ever breathes by gills. However, the 
undeveloped young have gill-like organs while still in the 
egg. This fact is true of still higher animals, the birds and 
the mammals, tending to show that the higher animals review 
in their development the general history of the lower forms. 
All the members of the Class have head, trunk, and tail. 
The skin of all is dry, and is covered with overlapping scales, 
or with plates. The organs of the head are eyes with lids, 
except in the snakes, with internal ears, and nostrils. The 
mouth is provided with teeth. The typical number of legs 
is four, with five toes on each foot. The snakes have only 
the rudiments of legs. 
The brain is larger in proportion to the rest of the nervous 
system than it is in the Amphibia and in the fishes. The 
heart shows the beginning of a separation into four chambers, 
whereas the Amphibia has three chambers, and the fishes 
only two. 
Most of the representatives of the Class come from eggs 
deposited by the female under ground. Tn some snakes the 
young are hatched from eggs within the body of the mother, 
and born in an active and developed condition. CHAPTER XII 
BIRDS 
The Ruffed Grouse. With the great increase in the 
population and the wealth of our cities, we have formed the 
habit of sending to distant rivers, lakes, forests, plains, and 
gardens for more and more rare and expensive foods. The 
habit of eating extravagantly has kept in touch with the 
habit of living extravagantly in other ways. Moreover, in 
the case of foods that cannot be replaced easily, the exces- 
sive eating makes the food more expensive, and in time 
tends to eliminate it altogether. 
Less than two generations ago there were in our country 
many species of game birds in large numbers. To-day sev- 
eral species are all but exterminated. The ruffed grouse 
is one of them. In that part of New York State, for example, 
included in the limits of the Cat skill range of mountains, 
it has not been many years since flocks of ruffed grouse were 
plentiful. To-day a person familiar with the woods rarely 
sees more than one or two grouse at a time, rarely coming 
upon any at all. The Catskills are all within one hundred 
fifty miles of New York City, and the “pot-hunters” range 
the mountains in the “open” season to the extent that they 
seem like a human pestilence. As Dr. William T. Hornaday, 
the author of Our Vanishing Wild Life truly says, “If 
we desire to prevent the extermination of this species, we 
must stop the killing altogether.” 
The ruffed grouse seems to be known to most persons by 
some other name. In the Catskills it is always called the 
“partridge.” In other parts of the country it is called the 
“pheasant.” Mr. Ernest Thompson Seton has helped to fix 
112 THE RUFFED GROUSE 
113 
its correct name, ruffed grouse, in the minds of nature-lovers 
in connection with the fanciful name “Redruff”; and be- 
sides, he has made its bold and dashing characteristics famil- 
iar to thousands of readers who might never have thought 
of distinguishing it from other game birds of large size. 
The chief features of the ruffed grouse are a ruffle of feath- 
ers about the neck of the 
male just in front of the 
shoulders. Both male 
and female birds have a 
topknot of feathers on 
the head. The color of 
the bird is rusty brown, 
with mottlings of black, 
gray, and white. As one 
sees the bird in the woods 
it appears to be the size 
of a nearly grown barn- 
yard chicken, but with a 
much longer tail. 
If you are afraid of hav- 
ing a palpitation of the 
heart, it might be well 
to try to see a ruffed 
grouse before one springs 
into the air a few yards 
away from you, for his 
setting off is the burr-r-r-r 
of the sudden turning of a mighty electric fan. There is a 
vigor about the sound as well as the sight. In all the quiet- 
ness of a summer morning in the woods the suggestion of 
alertness and winged power is boldly emphasized. 
Again in the springtime, the dum-dum-dum of the drum- 
ming male as he stands upon a log and signals to the female 
by beating his wings against the air (see Fig. 57), giving a 
Fig. 57. Ruffed Grouse. 
(Courtesy of National Audubon Society.) 114 
BIRDS 
sound like the boom of a distant drum,—this further gives 
us the feeling that here is the vitality of animal life per- 
sonified in a most attractive form. 
And then in August, when we suddenly come upon a 
sorely crippled hen-grouse, fluttering helplessly but with 
suspicious persistence in a given direction, we nevertheless 
follow her, wondering if we may not help the poor thing. 
Then we remember what someone has told us, or what we 
have read about the tricks of the mother-grouse and all her 
partridge tribe, and we try to find the little ones. We prob- 
ably got a glimpse of them at the flush, but the sight went 
out of our minds,—startled out. We look everywhere for 
them, but they have probably flattened their bodies against 
the soil or against the sim- 
ilarly colored leaves and 
spaces between, and we walk 
over them and miss them 
altogether. 
The Chicken Hawk. It 
is claimed by bird-lovers 
that there never was a 
greater injustice done to a 
bird than in giving to the 
red-tailed hawk its com- 
moner name of chicken hawk. 
It is not denied that this 
hawk does capture a few 
chickens, but the act is ex- 
ceptional. It is very easy for 
one to assume that any hawk 
that catches a chicken is the 
chicken hawk. But it may 
be the Cooper’s hawk, which is a real stealer of chickens, as 
well as of many other valuable birds. 
Fig. 58. Red-Tailed Hawk. 
(Courtesy of American Museum of 
Natural History.) THE WHIP-POOR-WILL 
115 
The red-tailed hawk has a rusty-brown tail. There is a 
broken, black band across the breast of the adult. Cooper’s 
hawk and the sharp-shinned hawk, both guilty of great 
interference with the welfare of man, have conspicuous 
cross-bars above and below the tail. 
In order to obtain definite knowledge of the relation birds 
bear to our economic interests, investigators have conceived 
the plan of first killing a considerable number of a given 
species. The stomachs of the birds are then examined with 
great care. After an investigation by this method, it was 
found that 85% of the food of the red-tailed hawk of 562 
specimens was made up chiefly of small destructive animals 
like field mice. 
Thus, it is apparent that without definite information as to 
the kind of hawk one sees flying about the farm, it is very 
likely that an excitable person may kill one of his best friends. 
Fig. 59. Whip-Poor-Will. 
(Courtesy of American Museum of Natural History.) 
The Whip-Poor-Will. Far off in the woods on cool 
summer evenings in June or July one may hear the whip- 
poor-will give its striking call, with the quick, snappy 
“whip,” the long, full “poor,” and the sharply accented 116 
BIRDS 
“will.” You count forty to fifty repetitions of the call, 
and sometimes you become tired of counting before the 
bird has finished its calling, and has gone off somewhere on 
the wing to open wide its cavernous mouth, scooping in the 
night-flying insects. 
A little later one hears perchance a queer “pwt” in a tree 
near at hand, and then the “whip-poor-will” call comes 
again, so strong and earsplitting as to cause you to marvel 
at what an insignificant bird can really do. Some persons 
claim that the whip-poor-wills make them nervous with 
their wild cries, keeping them awake far into the night. 
Perhaps they do; such persons should stay in the country 
longer. It may be that the elevated trains and the roar of 
other wheeled traffic, and their own feverish activities, 
gave them their “nerves.” 
A whip-poor-will may be startled by your trying to see it. 
It will fly away but you may not hear it go, for the wings 
are feathered so softly that it makes practically no sound on 
the wing. This fact may make the capture of its insect 
prey much easier. 
During the day the dull, gray color of the bird makes it 
very inconspicuous as it rests upon the ground in the woods. 
The eggs of the female are laid, two in number, upon dead 
leaves, with scarcely any appearance of a nest. 
The whip-poor-wills go south in October, not to return 
until the following April or May. 
The Crow. One of our best interpreters of bird life, 
Mr. Frank M. Chapman, author of Bird Life, says of 
the crow, “No one of our birds is better known, and still 
how ignorant we are of his ways! I am not sure that he 
does not know more about ours.” This refers of course 
to the shrewdness of the crow in understanding and antici- 
pating the acts of his arch enemy, man. It is often said by 
farmers that crows engaged in stealing in a cornfield pay THE CROW 
117 
slight attention to scarecrows, and even to a live man when 
he is armed with nothing more dangerous than a stick. They 
respect oidy a shotgun. At the same time, they appear to 
exhibit wholesome dread on account of the fate of one of 
their number whose dead body they may observe swinging 
in the wind from the top of a fence. 
Another bit of evidence of the intelligence and adaptive- 
ness of the crow is their frequent disposition to raid the 
nests of other birds that are under the direct protection of 
man. They overcome obstacles and take risks which while 
frequently turning out 
successfully for the 
time, bring down upon 
them the vengeance of 
man. This kind of 
thing, and the general 
stealing of corn, has 
tended to make the 
conviction of man cer- 
tain that the crow is a 
nuisance to be rid of. 
At the same time, we 
are forced to take the 
findings of painstaking inquiry concerning the facts. The 
United States Department of Agriculture has reported that 
the examination of nine hundred crows’ stomachs shows that 
the amount of good done by this bird in destroying grass- 
hoppers, June-bugs, cutworms, and other injurious insects 
exceeds the loss caused by the destruction of corn. 
The Department recommends that before planting corn, 
the kernels be soaked in water over night, and then dropped 
into a solution of soft tar. The coated kernels may be trans- 
ferred to wood ashes or plaster of Paris to be made fit to 
handle in planting. Crows will not touch grains of corn 
treated in this way, nor will they touch the seedlings that 
Fig. 60. Chow. 
(From Birds of New York.) 118 
BIRDS 
develop from the grains. Farmers who really make the soil 
produce its best are listening to all such suggestions that 
lead toward scientific farming. 
In the summer time, one frequently notices groups of 
three or four of these black birds sitting in a field or calling 
to one another from tree tops. The alertness of their actions 
and the vigor of their harsh caw, caw, with its manifold 
variations of emphasis make all hearers think they are hold- 
ing a council in preparation for a raid. Some old nursery 
rhymer has given us the direful song of a crow council, 
beginning: 
“There were three crows sat on a tree, 
And they were black as crows could be; 
Said one old crow unto his mate: 
‘What shall we do for meat to eat?’” 
In the winter, crows congregate in large numbers, and 
visit the tree tops of a definite set of trees throughout the 
season. In March they begin to mate, and in April they 
build large nests of sticks and bark in the forks of trees 
about thirty feet from the ground. They lay from four to 
six eggs that are bluish green in color, with dots of brown. 
The House-Wren. Perhaps every grown-up whose 
childhood was spent on a farm bears with him through life 
cheerful recollections of the family of house-wrens that 
nested and sang about the wood shed, the grape-arbor, or 
over the high cellar entrance under the wistaria vine. Their 
diminutive size, their bobbing bodies, with sprightly, up- 
turned tail, their stream of abandoned song, and their win- 
some fearlessness of man,—all appear to have met the gen- 
erous approval of everyone. 
No student of birds seems to have concerned himself with 
the question of whether wrens are economically important 
to man, or not. It appears to be sufficient that they bring THE NUTHATCH 
119 
happiness. This of course is more important than money 
saved, or money made. 
Wrens will make their own nests about the house, or they 
will build in any little box set up on a pole, or in a tree, for 
their benefit. Mr. Chap- 
man recommends that the 
hole be made no largei 
than a silver quarter of a 
dollar. Sparrows cannot 
enter the box then. Wrens 
fill the box full of twigs, ne 
matter what its size. Tlu 
nest proper they make oi 
dried grasses. Six to eight 
speckled, pinkish brown 
eggs are laid. The house- 
wren goes South in Octo- 
ber from the middle and 
northern states, and its 
place is taken through 
the winter by the wintei 
wren, that has been nesting further north. 
The Nuthatch. The White-breasted Nuthatch is a 
common bird in Eastern North America to be noticed climb- 
ing up and down, and going round and round the trunks 
of large trees. It is more skillful than any other bird in this 
sort of acrobatic food getting, and appears not to think the 
work hard, for it repeats a metallic, but not disagreeable 
note constantly while searching the bark for insect eggs, or 
larvae. It stays with us all through the year. 
Although the habit of visiting trees just described should 
be enough to enable one to recognize this bird, the black cap, 
the white sides of the head and the throat and breast, and 
the gray-blue back will make its identification doubly sure. 
Fig. 61. House-Wren. 
(Courtesy of National Audubon Society.) 120 
BIRDS 
About the twentieth of April, the female lays five to eight 
eggs. They are white in ground color and evenly and thickly 
speckled with reddish 
brown and lavender. 
The Hermit Thrush.— 
The family to which 
the hermit thrush be- 
longs contains some of 
our most famous song- 
sters, as well as birds 
less wonderful as sing- 
ers but interesting for 
other reasons. The 
great singers are the veery, the wood thrush, and the hermit 
thrush. Near kin are the ever friendly robin and the shy 
bluebird. 
It is not often a 
satisfactory way of 
giving information 
about birds to try to 
describe their way of 
singing by transposing 
into English syllables 
the notes of their 
music. It is almost 
as difficult to give an 
idea of the quality of 
a bird’s song that 
would help a person in 
recognizing the bird. 
But there is a quality 
in the song of the hermit thrush which has often been de- 
scribed as being like the rich tones of an organ, measured 
and stately. This is an accurate description, and in the great 
Fig. 62. White-Breasted Nuthatch. 
(Courtesy of American Museum of Natural 
History.) 
Fig. 63. Hermit Thrush. 
(From Chapman: Bird Life.) SUMMARY OF BIRDS 
121 
arches of the forest the wonderful, ringing notes fill the aisles 
with overpowering melody. If you hear a hermit thrush, you 
will probably never forget it. 
The hermit thrush is smaller than its relative, the robin, 
being only about seven inches long. Above, it is cinnamon 
brown. Beneath it is white with black spots in rows on the 
breast. 
The migrations of this bird extend from our northern states 
in summer time to the Gulf of Mexico in winter. While 
migrating, it travels by woodlands, but spends a great deal 
of time near the ground. The eggs resemble the robin’s 
in being bluish green. 
Summary of Birds. The Class Aves (Birds) is so dis- 
tinct from all others that anyone could give the character- 
istics. Although birds spend much of their time on land or 
in the water, they are especially adapted to life in the air, and 
on the wing. Their wings are broad and are controlled by 
very strong muscles that are able to lift the body and send 
it forward with great power. Only the lowest birds like the 
ostrich and the cassowary are unable to fly. The possession 
of feathers is indeed more characteristic of birds than is the 
ability to fly, for bats, squirrels, fishes, and insects can fly, 
but members of no other Class than birds have feathers. 
Birds have eyes with eyelids, ears with an external open- 
ing as in man, and nostrils. The mouth is without teeth; 
but as a compensating organ, there is a gizzard into which 
the food passes from the gullet to be ground up by strong 
muscles, working against pebbles and grains of sand that 
have been swallowed before the food enters. 
The brain of birds shows a still larger relative size than does 
the brain of reptiles. The heart is divided into four separate 
chambers with the result that birds have a more perfect circu- 
lation of the blood than is possible with lower animals. Con- 
nected with the perfect and complete circulation is a greater 122 
BIRDS 
oxidation, and the resulting heat in the body. The body 
temperature of birds is several degrees higher than the 
temperature of human beings. 
Most birds after the egg-laying incubate the eggs until 
the embryos have developed into fully formed young. After 
the hatching, the adults feed their young for varying periods 
of time. Thus begins in an organized manner the habit of 
caring for the young beyond the period of birth. Still greater 
development of this habit takes place in the next Class. CHAPTER XIII 
MAMMALS 
The Opossum. The most primitive animal in our 
country that suckles its young is the opossum. In a very 
definite sense it is an immature mammal, for the young are 
born in a partially undeveloped condition. They are placed 
Fig. 64. Opossum. 
(Courtesy of American Museum of Natural History.) 
when born in a pouch under the body, where they must 
remain for a time drawing nourishment from the mother 
until they are strong enough to exhibit some sign of inde- 
pendence. Not until the young are five weeks old are they 
able to venture away from the mother. 
Our species of opossum is called the Virginia opossum, 
123 124 
MAMMALS 
although it is found from New York, Michigan and Cali- 
fornia southward throughout South America. It is best 
known, however, in our southern states. 
Wherever the opossum lives its habits seem to furnish 
amusement for everyone, except the farmer whose chickens 
the vandal steals. Nearly every southern country boy has 
had his encounters with the opossum, and doubtless has 
enjoyed the experience of being occasionally outwitted by 
a creature so generally slow-witted and comical. 
The opossum is a short-legged, long-bodied, gray, bristly- 
liaired quadruped, about fifteen inches in length. The head 
is white, pointed, and set with eyes that resemble two black 
shoe buttons. The tail is about twelve inches long, and is 
without hair. 
Everything is grist that comes to the opossum’s mill. 
It feeds on fruit, vegetables, insects, eggs and birds in the 
nest, chickens, and roots. It is a night hunter, and sleeps dur- 
ing the day in hollow logs and in trees. 
While the opossum is hunting, it may also be hunted. 
Anyone can capture an opossum, for it cannot run fast, 
and will fall over “dead” at the least assault. It may then 
be picked up by the tail, and carried until you get tired and 
lay it down for a moment. When your back is turned the 
opossum will get up and slip away. Even when you bear 
it to the kitchen, it will not resist. The fact that roast 
’possum is good has taught it nothing. 
In spite of the defenseless makeup of the opossum, it is 
holding its own more successfully than are many other ani- 
mals that are preyed upon by man. Without question much 
of the success of the species depends on the fact that a great 
many young are born. The young stay with the mother 
about two months, and soon thereafter another litter is ready 
to take the places of those that have left. When we realize 
that seven to eleven young are born at a time, we under- 
stand the secret of their success as a species. THE RIGHT WHALE 
125 
The Right Whale.— —Whales are mammals. The external 
fish-like form adapts them to swimming through the water. 
The tail being placed horizontally adapts the animals to 
the constant necessity of swimming to the surface for air. 
There is no hair on the bodies of whales except for a few 
bristles about the chin. Whales are kept warm by a non- 
conducting “blubber,” a dense layer of fat immediately 
under the skin. The fore-limbs of whales, though reduced 
to mere paddles with no power of motion except at the 
shoulder joint, have all the bones, joints, and even most of 
Fig. 65. Right Whale. 
(Courtesy of American Museum of Natural History.) 
the muscles of the human arm or hand. Rudiments of the 
hind-legs are found deep in the interior of the animal. 
The Greenland or Arctic right whale (Baloena mysticetus) 
attains the length of forty-five to fifty feet. The head ex- 
ceeds one-third the entire length of the animal. The cavity 
of the mouth is greater than that of the thorax and the ab- 
domen together. The upper jaw is narrow, greatly arched 
backwards, increasing the height of the cavity and allowing 
for the great length of the whalebone blades. The floor of 
the mouth has the shape of an immense spoon. 
The blades attain the number of three hundred eighty or 
more on each side. Those in the middle are sometimes twelve 
feet long. They are black and highly elastic, and fray out 126 
MAMMALS 
at the inner edge into long delicate hairs. By this apparatus 
the right whale is enabled to capture and swallow immense 
masses of the minute Crustacea and pteropods that are abun- 
dant in the seas. The large mouth enables it to take in at 
one time a great deal of water filled with these small organ- 
isms, and the length and delicate structure of the whalebone 
provide an efficient strainer by which the water can be 
drained off. 
Whalebone is horny in character, and is very elastic. It 
is largely replaced now in commerce by steel, but it is still 
used among dressmakers and milliners, and in the brush 
trade. As much as $12,500 a ton is now paid for whalebone. 
The “blubber” of a whale supplies from two to three tons 
of fat which is stripped off after the captured whale is 
fastened to the side of the ship, or after being towed to a 
harbor. 
Whales are attacked from small boats by means of har- 
poons which are short spearheads attached to a pole and a 
long rope. They are also shot with a harpoon-gun from a 
vessel. Explosive harpoons have been used since about 1865. 
Whale-fishing is still going on in all parts of the world, but 
with very few vessels of the various nationalities. 
The Prong-Horned Antelope. In Africa there are scores 
of species of antelopes; in America we have never had more 
than one. Up to about the year 1875 our species, the prong- 
horned antelope, was abundant from Canada to Mexico 
throughout the great plains region as far west as California. 
To-day there are but a few herds in any part of its former 
range. 
The prong-horn is related to the deer and also to the 
wild goat. It is a graceful, swift-running antelope, about 
thirty-eight inches high at the shoulders. The male has 
two horns about twelve inches high, hooked at the top with 
one fork extending over the eye. The female is without THE PRONG-HORNED ANTELOPE 
127 
horns. As is the case with the deer, the horns are shed every 
year. In color the antelope is yellowish brown on the back 
and part way down the sides, and white below. The rump 
is conspicuously white. 
When the prong-horn was plentiful, great herds of them 
roamed the prairie, being successful in maintaining them- 
selves against wolves and other enemies, until the railroads 
penetrating the West 
brought man into closer 
relation with them. 
Hunters slew them for 
their valuable flesh, and 
wire fences prevented 
them from reaching 
places of shelter in the 
winter, thus causing the 
loss of thousands by cold 
and starvation. 
It would be difficult 
to find a more splendid- 
ly endowed wild creature 
than the prong-horned 
antelope, or one that has 
been pushed to the wall 
more quickly. Its great 
power of vision, superior 
to that of the deer, and 
its fleetness, also superior to the running ability of the deer, 
might have made it possible for them to persist as the deer 
tiave done. But antelopes do not breed in captivity as do 
the deer. For this reason it has not been possible to estab- 
lish herds of antelopes. 
Nevertheless, it is quite a simple matter to tame an ante- 
lope, and in a short time to make an interesting pet of one. 
The author still has tender recollections of a pet antelope 
Fig. 66. Prong-Horned Antelope. 
(Courtesy of American Museum of Natural 
History.) 128 
MAMMALS 
owned by him in his boyhood days on a Western Kansas 
ranch. He captured the little fellow, then perhaps but three 
weeks old, with the help of a dog and a cow-pony, after two 
consecutive chases of a half-mile each. During the long 
five-mile ride of boy and antelope to the ranch, it seemed 
that it would be impossible for the great, frightened eyes 
of the timid creature ever to show any sign of becoming recon- 
ciled to a human being. But that night it drank readily from 
a pan of milk, and the next day when experimented with in 
the corral, it followed its master about. After that, the pet 
followed everywhere, even when the master was on horse- 
back, dodging the curious cattle with great skill. One night 
after the antelope had been under the care of human beings 
for three weeks, a sudden storm drove it away from the 
ranch house. The next day its little body was found in a 
near-by gulch. 
Many persons have had successes with making pets of ante- 
lopes, and it appears especially unfortunate that we cannot 
save the species because of its failure to breed in captivity. 
The Chipmunk. The chipmunk is a diminutive but a 
typical representative of the group of mammals called 
the gnawers. It has the typical sharp front gnawing teeth, 
so well exemplified in the gray or red squirrel, or in the rabbit 
or the rat. And what is more important to our purpose, 
the chipmunk is accessible in a friendly way to everyone 
who cares to watch it with patience. As a matter of fact, 
one cannot help watching it. 
Whatever the species, the habits of all chipmunks are 
very much the same throughout our country, except that 
the particular environment or kind of fence may make the 
habits appear different, for a fence is just as necessary to a 
chipmunk as are the nuts it finds and the young lettuce and 
carrot leaves it steals from your garden,—which you should 
not begrudge if you can possibly spare them. Trees are used • THE CHIPMUNK 
129 
for shelter, too, but trees are not the best places for chip- 
munks, because they are not swift runners, and they cannot 
fight off hawks and crows. 
Into the crevices of rocks and under rails and boards, 
and also into burrows in the ground, the chipmunks may 
go, but not entirely free from the pursuit of their most dan- 
gerous enemy, the weasel. Chipmunks do not fight back. 
But they are able to prevent their own extermination by 
having many young, and by never going far from home. 
One other factor that operates in their favor is that their 
Fig. 67. Chipmunk. 
(Courtesy of The University Society, Inc., publishers of the 
“Nature Lovers’ Library.”) 
successful enemies, the weasels, the foxes, the mink, and 
the hawks are occupied with other matters beside. This 
fact always helps to maintain those complicated relations 
of creatures to one another which we may call the balance 
of life chances. 
As soon as the nuts and grains begin to ripen in the sum- 
mer, you may see chipmunks making many trips along the 
fences to their larders beneath. They are carrying cheek 
pouches full of the products of the country to store them up 
for the winter. They stay closer at home than ever during 130 
MAMMALS 
the stormy days that follow, but when the sun shines brightly 
they come to the light even in the winter time and enjoy 
themselves in it. 
In old stone fences one often sees hickory or butternut 
trees growing from the 
midst of the rocks, far 
from older overhanging 
trees. Doubtless most 
of these trees developed 
from nuts that were 
stored but overlooked by 
chipmunks. 
Bats. Of bats of all 
kinds it is customary for 
people to believe the 
worst. Whenever per- 
sons are ignorant of facts 
they usually do believe 
the worst. There are 
two reasons why we are 
generally ignorant of the 
facts about bats. One is 
that they are inhabitants 
of the night; the other 
is that our ancient prej- 
udices concerning any- 
thing and everything 
that we hear disagree- 
able tales about tend to 
keep us from wanting to know about bats. 
There are many kinds of bats scattered throughout the 
world in the torrid and temperate zones. Practically all 
the bats of our country belong to one family, and are spoken 
of as the common bats. They are small mammals with a 
Fig. 68. Bat. 
(From Linville and Kelly: General 
Zoology; Ginn and Company.) THE FUR SEAL 
131 
head and body two and one-half inches to three inches in 
length, and with a short tail. Their bodies are covered with 
red or gray fur. The front legs are very long, and the toes 
or fingers of this pair are extremely long and spread widely 
apart. These fingers form the framework of a naked mem- 
brane that stretches from the first finger back to the hind 
legs and even to the tail. The thumb is very short; the 
thumb-nail is hooked, and can be used for climbing and for 
supporting the body when at rest. But the customary posi- 
tion when at rest during the daytime is that of hanging by 
the hind legs, head downward. 
After sunset and until dark, many of the “birds” you 
see flying swiftly about, turning suddenly, and flopping this 
way and that, seeming a trifle awkward, but getting through 
the air and around obstructions with amazing skill, are not 
birds at all. By this time you must have guessed, they are 
bats. They are looking for insects, and they capture enor- 
mous numbers of them. They are not bearing live insects 
of unwelcome species in their fur, which may in that way 
enter your house, nor will the bats disarrange your hair. 
These bats do not interfere in the least with human welfare, 
but promote it as vigorously as toads do. 
In the daytime, bats sleep in darkened protected places, 
as of the roof of barns, or in caves, or even among the leaves 
of a chestnut tree. 
The Fur Seal. In the tragic story of the fur seal we 
learn a great deal about ourselves, how within a generation 
of men an animal little known or prized came by dint of 
“advertising” and business promotion to be considered the 
most valuable of fur animals. We also learn how the fur 
seal came to be the occasion of serious international com- 
plications. It is not the fault of the fur seal, nor of any other 
enemy than man, that within forty years the number has 
decreased from millions to limited thousands. 132 
MAMMALS 
The fur seal belongs to the group of marine mammals 
known as sea lions. They have four legs that have become 
modified into flippers adapted to rapid and skillful swim- 
ming. The front pair are triangular in form, and are without 
hair or claws. The hind pair show the toes with webs be- 
tween. The head bears small, sharp-pointed ears, and strong 
bristles about the mouth. An adult male will reach the length 
Fig. 69. Fur Seal. 
(Courtesy of American Museum of Natural History.) 
of seven feet and the weight of over four hundred pounds. 
The fur seal has its headquarters on the Pribilof Islands 
in Bering Sea. The seals live on these islands from the first 
of May to the end of November. During that time the 
young are born. When they are about six months old, they 
and all the seals of the islands “go to sea.” They migrate 
southeastward toward the coast of southern California, 
then bear north off the coast of Oregon, British Columbia, 
and Alaska, returning to the Pribilof Islands where they 
arrive again about the first of May. TIIE FUR SEAL 
133 
It is a matter of history that Alaska and the adjacent 
islands were purchased from Russia by the United States in 
1867. At that time there was practically no fur seal industry, 
but within five years the company to which the United 
States had leased the Pribilof Islands began to spend con- 
siderable sums of money to develop in London a trade in 
sealskins. In a short time the company was able to get 
good prices for the 100,000 skins of young males which the 
government had given them permission to kill on the islands. 
With the encouragement produced by wide advertising in 
the centers of fashion in Europe and America, the price went 
up, and the demand became greater than the supply of 
100,000 skins permitted by the contract. The result was 
that many independent ships from America and Canada at 
first, and from Japan and Russia later, began to kill the 
seals indiscriminately during their migration in the sea, as 
well as females that went to sea on short trips from the is- 
lands to obtain food. Naturally, many of these seals were 
females bearing unborn young. The effect of this indis- 
criminate killing was a considerable reduction in the number 
of seals that returned to the islands each May, and a gradual 
extermination by the destruction of the unborn young, as 
well as the young that had starved because their mothers 
had been slain while at sea in search of food. Our govern- 
ment seized many ships that were engaged in what was con- 
sidered illegal capture, and began negotiations with other 
governments to stop the stealing. 
Negotiations have been going on since 1887, with vary- 
ing success and loss of money in damages by our govern- 
ment, for the control of the high seas is a matter that no 
nation is willing to yield as a principle. No satisfactory 
settlement of the problem of the right to destroy the seal 
has been reached yet. Death by killing and death by disease 
has greatly reduced the ranks of the fur seal, and to-day 
it is practically doomed to extermination. 134 
MAMMALS 
The interest of the Treasury Department of our govern- 
ment has always been in the financial returns from the two 
little dots on the map of Bering Sea. Already they have 
brought us more money than the entire cost of all Alaska. 
Besides, there are millions of dollars invested in the industry, 
and thousands of men making their living by it. However, 
one phase of the whole question has been given little thought, 
and that is the extent of the real need for sealskin furs. So 
far as we can see now, no condition of human life has arisen 
since the year 1867, which seems to require that our bodies 
should be wrapped in furs that cost from $200 to $1000 a 
set. If any such condition had arisen, life would go hard 
with those who could not afford to spare, or did not even 
have, that much money. Of course, we are fully aware of 
the fact that men engaged in promoting fashions find their 
greatest opportunity to get rich in the encouragement which 
they know how to give directly or indirectly to other men 
to purchase expensive attire for their wives and daughters. 
The entire industry of seal-catching has been built up on 
the basis of advertising and human vanity,—and all to pile 
up riches. Besides, our government has been put to great 
annoyance through international complications for the 
profit of a company of seal-catchers. The men who do the 
hard work and make a poor living by the capture of seals 
get but a small part of the return. And they might be better 
employed in working to supply some real human need. 
Furthermore, there is no question about the fact that 
seal fur as worn in the women’s garments does not give any 
more protection from cold than is afforded by good wool 
garments, the manufacture of which does not involve the 
death of any animal, nor does it even involve pain. 
The Weasel. The weasel is one of the smallest flesh- 
eating mammals in our country, yet it has a look about its 
face that woidd make you stop and catch your breath, THE WEASEL 
135 
something as you do when the tiger at the “zoo” or circus 
looks at you through the bars. We do not need to consider 
what the weasel would do if it were five times as big as it 
is. For its own purposes it is large enough. With its pres- 
ent size and strength it can kill rabbits, grouse, ducks, and 
chickens, and they are each more than five times the size of 
the weasel. As already recorded in the story of the chip- 
(Mounted Specimens; Courtesy of American Museum of Natural History.) 
Fig. 70. Weasel. 
inunk, the weasel can follow a chipmunk into its burrow. 
There is thus great range to the size of the weasel’s prey, and 
abundant testimony to the persistency in its character. 
The weasel is one of the most bloodthirsty of all flesh- 
eating animals. It is said to kill sometimes simply for the 
sake of satisfying a murderous disposition. Although its 
merciless inclinations are directed often against rats and 
mice, it is a question whether the benefits from that sort 
of activity overbalance the loss sometimes resulting from 136 
MAMMALS 
the trespassing of weasels on the precincts of the hen 
roost. 
On the approach of winter, the fur of the weasel changes 
from brown to white. Doubtless, the white color helps to 
render the weasel inconspicuous to its intended victims. 
Thus, protective resemblance has its counter advantage in 
aggressive resemblance. Some animals gain advantage through 
the similarity of their color to the general surroundings by 
escaping the notice of their pursuers; the weasel and some 
others gain by the similarity in color to surroundings while 
they are pursuing. 
Summary of Mammalia. Like the birds, the mammals 
stand out clearly as a Class with definite characteristics. 
Mammals are characteristically land animals, although 
many spend some or all of their time in the water. Very 
few mammals can fly. 
The skin of mammals is covered with hair. No other 
class has this kind of covering for the body. The two pairs 
of legs have a variable number of toes. 
Mammals have eyes with lids, ears with external sound- 
collecting organs with passageways leading to the “drum,” 
and a pair of nostrils leading to the lungs. The nostrils 
carry the air over sense-organs generally very keen in the 
recognition of odors. The mouth is supplied with teeth for 
crushing and tearing the food. 
The brain of mammals shows the greatest size of any 
Class in relation to the extent of the nervous system and to 
the weight of the body. In this Class there is the highest 
development of mental capacity of any. The circulatory 
system is complete, there being four chambers in the heart, 
and a complicated set of blood-vessels carrying the blood 
away from the heart and back again. 
The highest manifestation of caring for the young is to be 
found in the mammals. The young ar<£ born i.p an active. SI MMARY OF MAMMALIA 
137 
but usually temporarily helpless condition, and are fed on 
milk produced by the mother. In many species the further 
care of the young extends over many months, while in man 
the period of care extends over many years, including as it 
does the training and the education in the period of youth. 
During the time of training and protection, the various 
species of mammals naturally impress upon the young the 
experience which the species has as part of its characteristics. 
In our own race, the better protected and trained the young 
are, the better it is for the individuals, and the better for 
the succeeding generations. CHAPTER XIV 
ANIMALS FROM THE BEGINNING OF TIME 
The Fabled and the Real. There have come down to 
us tales from mythology and from ancient natural history 
which describe animals stranger than any we have ever seen 
“in the flesh.” But the efforts of the imagination of man as 
portrayed in the fabled unicorn, or in the impossible centaur, 
are far outdone by the actualities laid before our eyes in the 
record of the rocks,—records that contain the fossil remains 
of creatures uncommon in form and gigantic in size. Im- 
pressive as is the sight of a museum full of the animals of the 
past, it is still more impressive to consider the vastness of 
the time that must have intervened since these and other 
less conspicuous animals lived and moved about on pre- 
historic land, or in sea and lake. 
The Vastness of Time. Although we may feel inclined 
to warn against the unguarded use of the imagination in deal- 
ing with facts of science, nevertheless, scientific imagination 
must be employed in the effort to encompass the well-nigh 
inconceivable features connected with the study of life upon 
our planet . We have been accustomed to dealing with years 
in measuring time; now we must begin to think of millions 
of years. The time that has elapsed since life began to exist 
upon the earth is so great that it is practically unthinkable; 
hence, the effort to measure it in terms of years is almost 
hopeless. 
Life began a long time after the planet itself was formed, 
and this early life must have been in small green plants, 
since small things logically precede large ones, and since 
138 LIFE AND THE ROCKS 
139 
green plants are able to build up their protoplasm out of in- 
organic materials, such as water, minerals in solution, and 
carbon dioxide from the air, while animals live upon the 
organic material obtained directly or indirectly from plants. 
Life and the Rocks.——Our knowledge of animal life upon 
the earth is entirely dependent upon certain facts primarily 
dealt with in the science of geology. These facts have to do 
Fig. 71. “Pocket” of Fossils. 
(Courtesy of American Museum of Natural History.) 
with the wearing down of the surface of the soil by rains and 
by the action of the water in brooks and rivers, and with 
the subsequent deposition of the fine particles in lakes, or 
in the sea at the mouths of rivers. Animals that have shells, 
like the Foramenifera (p. 9), or the clams (p. 74), or the 
lobster (p. 65) tell the story of their presence when the 
deposits become hardened into stone, and are lifted above 
the wrater by an upheaval of the surface of the earth in that 
region. Likewise, the bones of the higher animals are pre- 
served after their owners have lost their lives through the 140 
ANIMALS FROM THE BEGINNING OF TIME 
drying up of bodies of water, a catastrophe which would 
involve the destruction of fishes in the water and also of 
hordes of land animals driven there by droughts and weak- 
ened by being long deprived of water. Vast “pockets” of 
the fossils of animals have been found in solid rock in such 
condition as to lead to the supposition that catastrophes 
of this kind have happened many times; and they are still 
happening in deserts and in flooded areas. 
Another very common occurrence is the discovery of fos- 
Fig. 72. Pompeii Excavated from Stratum of Volcanic Ash. 
sils imbedded in the solidified dust of ancient volcanoes. As 
recently as the destruction of Pompeii (A. D. 79), the ash 
and cinders from Vesuvius covered and preserved entire 
the bodies of dogs and men. In Eastern Oregon a consider- 
able portion of the country is a vast stretch of volcanic dust. 
From this region many fossils have been taken. 
In all times the wind has been a very active agent in carry- 
ing dust and even sand to considerable distances, covering LIFE AND THE ROCKS 
141 
up and preserving the fossils of certain creatures. The wear- 
ing down of land masses, the deposition of the particles car- 
ried by the water, the solidifying of the soft material into 
stone, the subsequent elevation above the water by upheav- 
als, the breaking up of rocks into soil, and a renewal of the 
wearing down of the new land masses, are phenomena that 
have been going on since the beginning stages of the earth’s 
history. Depending upon the character of the minerals in- 
volved, the rocks have been limestone, sandstone, shale 
(composed of clay), or volcanic dust and lava. If a given 
portion of the earth, for example the Gulf of Mexico, remains 
undisturbed by upheavals for a long period of time the bot- 
tom of the area would come to have very great thickness. 
Layers or strata have been thus formed with a thickness of 
over ten 1 housand feet. 
We know the thickness of strata only when we see great 
rifts, like that of the Grand Canyon of the Colorado, cutting 
through one after another, or when the strata have been 
tilted slightly by an upheaval, and erosion has cut off and 
exposed a diagonal section through many strata. If all the 
strata that have been formed here and there in lake and sea 
since the beginning of this process were placed one above 
another the mass, it is estimated, would be from twenty to 
twenty-five miles thick. Although there are many regions 
where strata lie superimposed, it is very rare that more than 
one period of time can be studied at or near the surface in a 
limited area, except where there are outcroppings as in the 
deep valley or gulch of a river. 
Although many disconnected areas may have been formed 
by deposits at the same time, or may have belonged to the 
same era, it would be difficult to prove it if it were not for 
the evidence to be obtained from fossils. So important is 
this evidence that it acts as a great flood of light illuminating 
the history of the world from its beginning. In the first, 
place, the simplest forms of animal life, the invertebrates 142 
ANIMALS FROM THE BEGINNING OF TIME 
Fig. 73. Model of Grand Canyon of the Colorado River. 
(Courtesy of American Museum of Natural History.) CHANGES IN LAND AND INHABITANTS 
143 
or animals without backbones, are found in strata that from 
their position underneath others must have been formed 
first. The higher forms are found only in the upper strata. 
The most highly developed animals, the mammals, are the 
last to appear, being found only in the uppermost strata. 
Changes in the Land and its Inhabitants. It is a well- 
known fact in zoology that a given species is developed only 
where there is definite continuity within its range of dis- 
tribution. For example, the chipmunk is found in North- 
eastern United States, and nowhere else. If it were found 
separately in another part of the country, or in Europe, the 
fact would call for explanation. We have the English spar- 
row occurring in America, but we know that the species was 
imported to this country within the past century. 
Now, the rocks and soil of great stretches of territory in 
the states of California, Oregon, Montana, Wyoming, Idaho, 
and Colorado once covered in part by fresh water lakes con- 
tain the fossilized bones of lions, tigers, elephants, rhinoce- 
roses, camels, besides other animals still more familiar to us 
through daily contact. They lived in vast hordes probably 
all over America, but the conditions for the preservation of 
their bones was favorable chiefly in the region named. The 
nearest present day relatives of these prehistoric animals 
are to be found in the wild state nowhere but in Africa or 
India. Two very important conclusions can safely be drawn 
from the facts related; first, there must have been land con- 
nection between America and Europe, or between America 
and Asia, at the time these animals lived in America, and 
secondly, the climate must have been very much warmer 
then than it is to-day. There are many proofs that there 
actually were land connections of considerable width across 
the Atlantic Ocean in the region where Greenland now lies, 
and also across the Pacific Ocean at Bering Strait. In those 
far off times palms grew in Canada, for we find their trunks 144 
ANIMALS FROM THE BEGINNING OF TIME 
and leaves in the coal strata there. Strange as it must ap- 
pear, the conditions were entirely favorable for the migra- 
tion of animals from America to Europe and thence to Africa 
by way of former land connections by way of Greenland or 
across “Bering Land” (where the Sea now is). Animals 
could have migrated quite easily from those countries to 
America, and they undoubtedly did. 
Changes in Conditions and in Species. Lions, tigers, 
elephants, etc., are easily distinguishable from one another; 
and it woidd be almost as 
easy to distinguish the species 
of those eras from animals of 
the same type found to-day. 
The fact is that species have 
changed very greatly, giving 
way to others more or less 
closely related to the old. In 
not a few instances general 
kinds or types of animals 
have disappeared altogether. 
For example, we have no 
more of the gigantic lizards 
which stood on their hind 
legs, reaching a height of 
probably twenty-five feet and a length of over eighty feet. 
We have none of the old type of giant bird, and no reptile- 
like bird. In fact, vast numbers of species have gone out 
of existence, although certain species or their very near kin- 
dred still exist to-day. Some explanation of these facts is 
called for. 
It is already clear that the climate of the planet has been 
quite different from what it is now. Although Canada had 
tropical conditions of climate, it was not only once but even 
many times covered with a vast sheet of ice. Once the field 
Fig. 74. Head of Saber-Tooth 
Tiger. (Courtesy of American 
Museum of Natural History.) HOW THE NEW ARISE 
145 
of ice extended as far south as a line running from Long Is- 
land, New York, through Pennsylvania, Ohio, Indiana, Ill- 
inois, Missouri, Kansas, Colorado, Wyoming, Idaho, and 
Oregon. We know this from the occurrence of boulders 
brought down from the North in the gigantic glacier, and 
from scratches in the surface stone, and from other facts. 
Evidence also goes to show that desert conditions have 
followed eras of excessive moisture when great swamps 
covered the land. And again, the deserts gave way to moist 
conditions. 
Land was formed out of the sea and from the beds of lakes. 
Mountains were lifted out of the land by disturbances from 
within, or from the shrinking of the earth’s crust. Over a 
considerable area the climate was altered by the elevation 
of the land, or by its depression. 
The changes that occurred from era to era must have af- 
fected all animals, and all plants as well, but not all to the 
same extent or in the same way. But the food of animals 
would be changed undoubtedly by very slight changes in 
moisture and temperature. 
How the New Arise and the Old Disappear. It is a 
well-known fact of life in general that organic forms are 
showing constant change or variation in their own struc- 
tural or color features. These variations extend in many 
directions, and seem to be always fluctuating from genera- 
tion to generation, never the same, but except rarely never 
very different. The rarer but more important variations 
are called mutations, a word which means changes, but 
in a technical sense it means considerable or marked 
changes. 
In ancient as in modern times an animal that shows a 
mutation which tends to fit it more favorably for a given 
condition or activity will thereby become better fitted to 
succeed and to live to hand on down to its young the charac- 146 
ANIMALS FROM THE BEGINNING OF TIME 
teristic which aided the parent or parents to be successful. 
If the mutation is in a direction which is not favorable to 
success, or if the surroundings or environment change radi- 
cally, and the animal does not change, or manifest some abil- 
ity to adapt itself to changed conditions, the animal and its 
species will disappear. 
The most recent of all types of animals to develop 
has been the class of mammals. Mammals are more per- 
fectly organized than are the members of any other class; 
they have greater activity, they are more adaptable to 
varying conditions, they are more inventive, and perhaps 
most important of all, they show in greater measure than 
the other classes the ability which distinguishes man him- 
self, the ability to think. It has been thought by scientific 
men that the primitive mammals of predaceous type may 
have destroyed the eggs or the unprotected young of the 
great lizards. Thus, it would incidentally be apparent that 
those creatures which have a more perfect way of protect- 
ing their young, as the mammals have, woidd hold an advan- 
tage over less efficient beings. 
How Life is Classified in Time. Here and there in this 
chapter the word “era'’ has been used. We may now bring 
the term into more definite relation, and explain its connec- 
tion with strata and with the succession of animal life. A 
table is given below in which will appear some interesting 
facts. In the first column will appear the names of the Eras; 
in the second column will be the names of the Periods or 
subdivisions of the eras; in the third column will be given 
the name of the chief class or branch of animals characteris- 
tic of the time. Beginning at the bottom of the table and 
reading upward, the student may understand that the higher 
types of animals are not in existence until we approach a 
period in connection with which the species, or class, or 
branch is named. THE ORIGIN OF ANIMALS IN TIME IN NORTH AMERICA 
Era 
Period 
Chief Kinds of Animals Living 
Recent or Present 
Pleistocene 
Man 
(Glacial) 
Man, bison, horse, mastodon, impe- 
rial elephant, bears 
Cenozoic 
(Era of Newer 
Animals) 
Pliocene 
Megatherium, Glyptodon 
Miocene 
Seals, walruses, deer 
The Age of 
Mammals 
Oligocene 
Camels, titanotheres, rabbits, squir- 
rels, cat family (tigers, lions) 
Eocene 
Whales, ancestor of horse, Uintathe- 
rium, tapirs, rhinoceroses, Phen- 
acodus, dogs, bats 
Cretaceous 
Opossums, Hesperornis, Ichthyornis, 
Mosasaurus, turtles, Pteranodon, 
Triceratops 
Mesozoic 
(Era of Middle 
Animals) 
Jurassic 
Pterodactylus, Stegosaurus 
The Age of Birds 
and Reptiles 
Brontosaurus, Atlantosaurus, Ple- 
siosaurus, butterflies 
Triassic 
Ichthyosaurus, Mastodonsaurus, 
Dragon-flies, crabs 
Permian 
Pariasaurus, Sphenodon, Branchio- 
saurus, May-flies 
The Age of 
Amphibia 
Carboniferous 
Cochroaches, spiders, oysters 
Bony fishes, lung fishes, sharks, pill- 
bugs 
Palaeozoic 
(Era of Old or 
Devonian 
Ancient Animals) 
Silurian 
Armored fishes, scorpions 
Ordovician 
Barnacles, brachiopods, Bryozoa, sea 
urchins, crinoids, Foramenifera 
The Age of In- 
vertebrates 
Cambrian 
Peripatus, Eurypterida, Trilo bites, 
cephalopods, gastropods, starfishes 
Algonkian 
Coral polyps, hydroids, annelids 
Archean 
Sponges, Radiolaria 148 
ANIMALS FROM THE BEGINNING OF TIME 
Several of the names in the table above are of course un- 
familiar to the young student. In most cases they are the 
names of animals that are extinct. Some of these existed 
through an entire era; others lived through but a single pe- 
riod, which in itself might be as much as a million years. 
The study of the extinct species where their fossils are found 
in succeeding strata, shows a gradual separation from allied 
species, a slow development in some cases into a species of 
wide extent, great size of 
body, and hence of dom- 
inating importance in 
relation to other species. 
The climax is sometimes 
followed by a rapid de- 
cline and final elimina- 
tion. 
The trilobites lived 
from the Cambrian to 
the Devonian, and dis- 
appeared completely. 
But their fossils may be 
found all over the world. 
The author once col- 
lected a number on the 
upper slopes of Mount 
Stephen in the Rocky Mountains of Canada. The locality 
is about ten thousand feet above the level of the ancient 
sea, where the animals lived. The dinosaurs (meaning 
terrible lizards) are found from the Triassic to the Creta- 
ceous, within which period reptiles possessed the earth in 
the sense of dominating its organic life. The Thunder Lizard 
itself (Brontosaurus) living in the Jurassic period of the 
Rocky Mountain region was not great enough or adaptable 
enough to stem the tide of unfavorable conditions, when at 
the close of the Cretaceous period some catastrophe seems 
Fig. 75. Trilobite. 
(Courtesy of American Museum ofNatural 
History.) LIFE CLASSIFIED IN TIME 
149 
to have overcome the race of reptiles, leaving crocodiles and 
alligators to maintain feebly the reptilian age of terror. 
At some time in the Triassic period there began the class 
of mammalian animals. They were small and of a lowly 
type at first, but in the Cretaceous the number of species 
became greater, while the type resembled our opossum and 
the Australian kangaroo; they were marsupials. That is 
to say, they brought forth their young alive, but placed 
them in a pouch beneath the body to complete their forma- 
tion and to be fed from milk glands of the mother. It is 
Fig. 76. Brontosaurus. 
(Courtesy of American Museum of Natural History.) 
supposed that at this time Australia became separated from 
Asia, since the great island continent still has no native 
animals higher than the marsupials. 
But in the Eocene period mammals developed wonder- 
fully. Not only were there mammals of the perfect type 
of our most successful mammals of to-day, those that gave 
birth to perfectly formed young and nourished them and 
cared for them effectively, but there were also vast numbers 
of species of the type in existence in that day and age. How- 
ever, it is well to remember that the climax of the age of 
mammals was not to come for a long time, and that the 
existence of man himself was a matter of some millions of 
years in the future. No animal like him then existed. 150 
ANIMALS FROM THE BEGINNING OF TIME 
The horse began its long upward course of development in 
the Eocene. In that period Eohippus or the Dawn Horse 
made its appearance. This animal was between the height 
of a cat and a fox. Its head was shaped something like the 
head of a horse, except that the eyes lay about halfway be- 
tween the nose and the ears. The neck was short, the back 
was highly arched, the legs were short, and there were four 
toes on the front feet and three on the hind feet. It is 
thought that a still more primitive horse must have lived 
in the Cretaceous, and that it probably had five toes on each 
foot. The record of the Eocene rocks shows that Eohippus 
migrated from Asia, on which continent it had its beginning, 
across liering Land to western North America, where the 
long series of changes to the modern horse took place. 
Through the long Eocene the diminutive horse developed 
into a larger and larger type, an outer toe of the forefeet 
gradually becoming smaller until it was present only as a 
“splint.” In the Oligocene the race is represented by Meso- 
hippus, a horse about two feet high, with three toes on each 
foot, the side toes still touching the ground and the middle 
toe bearing a small hoof or toe-nail distinctly larger than 
those on the side toes. Merychippus appeared in the Mio- 
cene, and was three feet high. It had three toes on each 
foot, but the side toes did not touch the ground. Moreover, 
long teeth especially characteristic of horses were present, 
and the eyes had shifted back toward the ears, thus making 
room in the upper jaws for the long teeth. Finally, in the 
Pliocene the one-toed horse appeared very much as we 
know it to-day. 
In the Pleistocene period there were in North America 
as many as ten species of horses, some very small in size, 
and one larger than any horses now living. Some of these 
species became extinct; others migrated to every continent 
except Australia over the land bridges then existing. None 
was left in the Western Hemisphere. Our present day horse LIFE CLASSIFIED IN TIME 
151 
THE EVOLUTION OF THE HORSE. 
Fig. 77. Evolution of the Horse. 
(Courtesy of American Museum of Natural History.) 152 
ANIMALS FROM TIIE BEGINNING OF TIME 
belongs to a species that developed after the horses left 
America. After the horse became a domesticated animal 
in the service of man many of the species were brought over 
by the Spanish explorers. The wild horses that until recent 
years were abundant on our western plains came from bands 
that escaped from the Spanish conquerors in Mexico. 
A great deal of use has been made in this chapter of the 
common words “development,” “change,” “variation,” 
“adaptation,” “environment,” “decline,” “elimination,” 
etc. It is now time to inform you of a process in nature 
which involves all the factors described by the terms given 
here. The name of the process is Evolution. This process 
as you can see for yourselves has been going on since the 
beginning of time, but it was not until about one hundred 
years ago that scientists succeeded in formulating clear 
ideas about it. And it was not until the year 1859 that one 
of the greatest minds of all time, that of Charles Darwin, 
put the theory of Evolution on a sound philosophic basis, 
in a book which he called The Origin of Species. 
Since Darwin’s time the observations of biologists have 
resulted in some modifications of his conclusions, but the 
main principle remains unchanged. After reading about 
the rise and decline of races of animals, the appearance of 
new species and their final elimination, it may appear 
strange to you to be informed that at one time, and that 
not longer ago than the Civil War in this country, a person 
who taught that plants and animals are developed from 
other kinds somewhat different from those now living 
would encounter bitter opposition. But such is the fact. 
Darwin himself had to endure for many years the fierce criti- 
cism of the Church of England, until leaders in the Church 
came to see the truth and to acknowledge it frankly. 
In brief, Evolution explains the origin of species of animals 
and plants by bringing into organized relation these facts: 
(1) Organisms vary in every generation. Sometimes the LIFE CLASSIFIED IN TIME 
153 
variations are of considerable extent; such are called muta- 
tions. Those mutations which are of value to the organism 
in adapting it more completely to a particular condition in 
the environment tend when inherited to establish a new 
variety and finally a new species. (2) Through heredity 
the characteristics of a newly forming species are passed 
on from generation to generation as an established line 
except for the small and the large variations which continue 
as internal manifestations of the germinal substance. (3) 
The environment does not cause the variations which are 
continually appearing, but does offer to these variations 
the chance to develop under favorable conditions. (4) The 
environment which may be favorable to certain species, 
manifesting certain variations may be unfavorable to other 
species. Thus, a struggle more or less indirect may develop 
between the unsuccessful species and the organic and in- 
organic factors in its environment. Those species which 
do not become adapted to fit into some relation to organic 
and inorganic conditions, either by degenerating or by ad- 
vancing to a higher plane of organization, tend to disappear 
altogether. CHAPTER XV 
UP FROM SAVAGERY 
Man's Origin in Time. The apparently easy way in 
which the evolution of the horse lias been worked out by 
students of paleontology [Gr. palaeos, ancient (life); logos, 
science] may lead us to think that the natural interest we 
have in our own race should have inspired paleontologists 
to busy themselves with the forebears of mankind. As a 
matter of fact, prodigious efforts have been put forth for 
many years in all parts of the habitable globe to discover 
traces of prehistoric man. It is true much has been ascer- 
tained, but there are still important connections in onr line 
of progress upward from the lower animals which have not 
yet been proved. The future may hold in store for us much 
in this direction that will be interesting, but it is hardly 
likely that the main conclusions on the origin of man al- 
ready reached by science will be altered greatly. 
No one has ever discovered human bones showing that 
man existed in a period earlier than the Pleistocene, in which 
occurred the Great Ice Age or the Glacial Epoch. But 
crude man-made chips from flint rock have been discovered 
in the Pliocene of India. And there can be no doubt that 
man lived somewhere on the earth as early as the Miocene 
period, which would make the human race about one mil- 
lion years old. The evidence for this statement is somewhat 
complicated, but the main point of it is the fact that fossils 
of anthropoid apes, the nearest relatives of man, are found 
in the Miocene in central Europe. Since it is supposed from 
the evidence of bodily structure that the anthropoid apes 
and man came from a common ancestor, a creature that 
154 MAN’S RELATIVES 
155 
was more primitive than either, man must therefore havt 
existed at as early a time as the apes that were developec 
from the same stock. In the Pliocene the apes were driver 
into Africa by the increasing cold of the ante-glacial period 
We can only conjecture why no fossils of men of the Miocene 
period, or of the Pliocene period which followed immediately 
after, have ever been found. They may yet be found. 
Man’s Relatives. Although there are very many simi 
larities in bodily organ- 
ization in the apes and 
man, there is a great 
difference in the size of 
the brain of the two 
races. Nevertheless, as 
was pointed out by 
Huxley, the first great 
scientist to study this 
matter carefully, there 
is a greater difference in 
this regard between the 
lowest of the man-like 
apes and the gorilla, 
the highest, than there 
is between the size of 
the brain of the gorilla 
and the brain of the 
most primitive men. 
This should be taken 
to mean that we are 
different from the gorilla more particularly in degree than 
in kind. It has been maintained by paleontologists that 
in all the great races of animals the mutations toward a 
larger brain have been of the first importance, since through 
the brain development there would arise the ability of the 
Fig. 78. Skeleton of Gorilla. 
(Courtesy of American Museum of Natural 
History.) 156 
UP FROM SAVAGERY 
animal to adapt itself to new conditions. Thus brains have 
always been at a premium. It is believed that a consider- 
able mutation in the direction of a larger brain must have 
been the chief step of our far-off ancestors away from the 
ancient stock. 
His Birthplace and His Migrations. The birthplace 
of man is still one of the unsettled points in his history. But 
the probability is that he began his existence as a distinct 
species in or near the country now called Tibet. From 
there he migrated to all parts of Asia, to Africa, to 
Europe, and to the Americas over the land bridge connect- 
ing Europe with Iceland, Greenland and Canada, or pos- 
sibly from Asia when there was land connection to Northwest 
America. 
Undoubtedly the migrations occupied long periods of 
time. But all we are certain of is that in the early part of 
the Pleistocene period, possibly 750,000 years after man’s 
beginning, we find positive evidence of his presence in all the 
great continents. The material upon which our knowledge 
is based consists of a very few human skulls and other bones 
and of large quantities of stone implements. This material 
is found in the gravel of ancient river beds, under glacial 
drift of rock and gravel and sand, and in caves which served 
as the homes, the castles, and the stables of antiquity. From 
the stone implements we learn the occupations of our fel- 
lowmen of 100,000 to 200,000 years ago, and we learn the 
extent of their skill in making things. From the caves we 
learn their general habits of life, as well as their relations to 
the other animals of their time. From their bones we learn 
what manner of men, women and children they were in per- 
sonal appearance, for the bones are not only the framework 
of the bodies of animals, but they even offer sufficient basis 
for reconstruction drawings that show what probably were 
the external characteristics of form. THE OLD STONE AGE 
157 
The Old Stone Age. The most primitive of the ages of 
civilization of man is known as the Paleolithic aue. (Gr. 
palaeoa, ancient; lithos, stone), or 
the Old Stone Age. Sometimes 
it is spoken of as the Rough Stone 
Age. The age lasted from the 
beginning of the Pleistocene to 
something like 10,000 years ago 
in Europe. Many specimens of 
the crude, chipped, unpolished 
stone implements characteristic 
of the age have been found un- 
der the glacial drift in Minnesota, 
Ohio, Delaware, and New Jersey, 
as well as in the Pleistocene of 
South America, England, France, 
Germany, India, and Africa. These implements were arrow 
heads, spear heads, borers, and ax heads which probably 
Fig. 79. Old Stone Hammer. 
(From Evans: Ancient Stone Im- 
plements.) 
Fig. 80. Reindeer Engraved on Bone. 
(Courtesy of American Museum of Natural History.) 
were fastened to a wooden handle by throngs of leather. In 
the caves of France of the Paleolithic Age have been discov- 158 
UP FROM SAVAGERY 
ered also implements made of horn and bone, such as barbed 
spear heads, harpoon heads, and even a whistle made from 
the foot of the reindeer. 
The caves which were numerous in Western Europe of- 
fered the protection which must have been welcome to a 
species still without effective means of defense against 
stronger animals. In 
these caves families 
were reared, domesti- 
cated animals wrere 
kept, preparations for 
the chase were made 
a n d the captures 
brought back to be 
devoured, whatever 
was not devoured on 
the spot where it was 
captured. 
In the caves also the 
cave men left the evi- 
dence that they were 
as vain as savages of 
later date and other 
persons not usually 
classed as savages, for 
they painted them- 
selves with red hema- 
tite. They wore or- 
naments of snail shells, ivory plates from the tusks of 
elephants, and perforated teeth from the wv>lf, the ox, the 
ibex, the reindeer, the horse, and from other animals. But 
among the ancient savages there were artists, too, for they 
traced with a pointed flint pictures of fishes, horses, rein- 
deer, the ibex, the wild ox, and the mammoth or ancient 
elephant, on pieces of horn, bone, ivory and slate. Perhaps 
Fig. 81. Neanderthal Man. 
(From Painting by Charles R. Knight. Cour- 
tesy of American Museum of Natural 
History.) THE 0L1) STONE AGE 
159 
there is no evidence oi the antiquity oi man that we would 
be more ready to accept than this evidence that our an- 
cestors possessed artistic feeling and the self-taught skill to 
portray the things they saw and knew. 
The pictures and the bones of the animal neighbors of 
man serve to indicate that the climate of the ancient stone 
age in Europe was very cold,—much colder than it is to-dav, 
as well as to fix more ac- 
curately the time of that 
ancient era. 
Within the last cen- 
tury some bones ol 
Paleolithic man were 
discovered. Among the 
most interesting and 
instructive of these is 
the “Neanderthal Man’ 
whose skull and leg and 
arm bones were found in 
1856 in a cave in a smal 
ravine near the Rivei 
Rhine in Germany. A1 
first it was thought tha1 
the bones were those oi 
an ape, but later Huxle\ 
and other anthropolo 
gists (students of man' 
declared that they were 
the bones of Paleolithic man. In 1886 two skulls and 
other bones were found at Spy, near Namur, Belgium, 
lying near the bones of the wooley rhinoceros, the mam- 
moth, the cave bear, the hyena, etc., five of the nine species 
being extinct. Other paleolithic remains have been found 
at Heidelberg, Germany, at La Chappelle and at Dor- 
dogne, France, on the Thames in England, and in the island 
Fig. 82. The Java Man. 
(From Photograph of Model, prepared by 
Prof. J. H. McGregor. Courtesy of 
American Museum of Natural History.) 160 
UP FROM SAVAGERY 
of Java. The important features of these ancient men, as 
described by the late Professor R. Wiedersheim, of the Uni- 
versity of Freiburg, Germany, “are a low retreating and con- 
tracting forehead and an inwardly shelving occiput (back- 
head) indicative of a primitive type of brain and of powerful 
neck muscles, a high temporal ridge and an expanded palate 
(indicative of powerful jaws and jaw muscles; and further, 
the presence of ape-like 
brow ridges appears 
also to have been a ra- 
cial character.” Some 
of the ancient men were 
tall, while some were 
short and not so pow- 
erful. 
The New Stone Age.— 
Out of the Paleolithic 
Age slowly came the 
Neolithic or New Stone 
Age. Sometimes it is 
called the Polished 
Stone Age. In Europe 
the implements of the 
new stone age were 
probably made from 
5,000 to 10,000 years 
ago, in America as re- 
cently as the discovery 
of the Continent. In that time man physically was the same 
as he is today. The climate also was the same, having long 
before become milder than the great cold of palaeolithic 
times. Without doubt the more favorable climate made it 
possible for men to develop industrially and artistically more 
rapidly than they had before. 
Fig. 83. Cro-Magnon or Cave Man. 
(From Drawing by Charles It. Knight; Pho- 
tograph. Courtesy of American Museum 
of Natural History.) THE NEW STONE AGE 
161 
Before the new stone age the mammoth, the rhinoceros, 
the Irish deer, the great bear, the lion, the musk ox, the 
reindeer, the chamois, and the hyena had disappeared, some 
exterminated, and others driven away by the changing cli- 
mate. Newer forms came in and in some cases to be men- 
tioned later were domesticated by man. There are evidences 
also that man ceased to be chiefly a savage hunter, and be- 
came a tiller of the soil and a consumer of the product 
thereof. Probably he cooked his food, for his paleolithic an- 
cestors undoubtedly knew how to make fire. 
The implements which by their appearance give the name 
Fig. 84. Model of Lake Village. 
(Courtesy of American Museum of Natural History.) 
to the new stone age were ground to an edge and polished 
with great skill. There were arrow heads, knives, borers, 
scrapers, hammerstones, punches, pestles, and chisels. There 
is evidence that Neolithic men in some cases discovered im- 
plements left behind by their forefathers, and improved on 
them in accordance with the more modern methods of stone- 
craft. These implements are now often found at or near 
the surface of the Soil, or in rubbish heaps where numbers of 
fishermen collected, or near ancient lake dwellings. 
The lake dwellings or villages have been discovered in 
numerous sections of the shores of the lakes of Switzerland. 162 
UP PROM SAVAGERY 
The existence of these villages dates from the Neolithic Age, 
and continued down to the days of Rome. Thus we have 
communities living through the new stone age and into the 
subsequent ages of bronze and iron. The lake dwellers were 
skillful workers in stone, horn, bone, and wrood. The making 
of pottery was also general in the new stone age, but was 
unknown in the earlier age of man. By building their houses 
on piles the lake dwellers were able to avoid animal enemies 
and unfriendly beings of their own race, at the same time 
Druid Monuments in England. (Courtesy of American Museum of 
Natural History.) 
Fig. 85. Stonehenge. 
being near an inexhaustible food supply,—the fishes in the 
lakes. 
Among the most interesting and enduring records of the 
existence of men of the Neolithic age in Europe are gigantic 
blocks of stone still standing, notably near Stonehenge, Eng- 
land, and at Carnac, in Western France. These stones in 
accordance with their number and grouping are called men- 
hirs, dolmens, and cromlechs. The menhirs are single stones 
standing as a column; the dolmens consist in their simplest THE FOUR RACES OF MEN 
163 
forms of three stones, two standing on end and one lying 
across like the top of a table; cromlechs are vast open-air 
temples marked off in rectangular form by enormous stones 
standing upright into aisles and spaces for great numbers of 
people. The cromlechs were probably primitive places of 
worship. The dolmens are supposed to have been places 
for the burial of the dead, and also shrines to be visited by 
those who might desire to pray to the spirits of the dead. 
The menhirs were probably set up as monuments. 
An eminent ethnologist (student of the culture of the hu- 
man race), Professor A. D. Haddon, of the University of 
Cambridge, England, gives it as his conviction that “the 
distribution of the racial elements in the population of Europe 
is very similar to that of late Neolithic times.” Although 
the movements of peoples from one country to another have 
increased within historical periods, and especially since the 
means of communication have developed, the men of pre- 
historic times were themselves great travelers. This matter 
is of especial consequence when we come to consider the races 
of mankind and their origin. 
The Four Races of Men. As we know there are now 
four races of men, white, yellow, brown, and black, and many 
subdivisions of these. All of them belong to the same 
species, Homo sapiens (man wise). There is evidence to 
show that Paleolithic man and his ancestors were com- 
prised of several species, but only one has come down to the 
present geologic era. How and when in the distant past 
the four present-day varieties of men branched off from a 
common stock of course we do not know. One thing we 
are certain of, however, is that, the heat of the torrid zone 
had nothing to do with making men black, for many black 
men lived for long periods in South Africa in a climate quite 
as temperate as our own. Besides, there are other races liv- 
ing in the torrid zone that are not black. To be sure the fa- 164 
UP FROM SAVAGERY 
cial and skin color differences between the races may seem 
considerable, but the technical methods of study of the an- 
thropologists go deeper than these 
differences, and bring to light still 
other differences which in some 
measure overlap the differences 
we would notice, thus drawing 
the races into one great group. 
Some of these technical points 
we can appreciate easily. Fe>r 
example, we all know persons 
who have heads that appear 
much longer than they are wide; 
such are the long-headed types, 
called dolichocephalic. Others 
are more round-headed. The 
latter are called short-headed 
or hr achy cephalic. Long-headed 
types are found in the white race from the North of Europe 
(from which region most of us in 
America have come). They are 
also found as the regular form of 
head of the American Indian, the 
Negroes, the primitive Austra- 
lian, and the Esquimaux. Short- 
headed types are general among 
the dark-featured people of the 
white race in France, Italy, Ger- 
many, Austria, Greece, Russia, 
and among the yellow race of 
China and Japan. 
Other interesting details of 
value in measuring mankind for 
classification are the prominence 
of the cheek bones, the length of the lower jaw, the width 
Fig. 86. Dolichocephalic 
(Long) Head. 
(Courtesy of American Museum 
of Natural History.) 
Fig. 87. Brachycephalic 
(Round) Head. 
(Courtesy of American Museum 
of Natural History.) TIIE CONTINUANCE OF MUTATIONS 
165 
and prominence of the nose, the slope of the forehead, and 
the height of the skull above the ears. It is interesting to 
note that all these characters are intimately associated with 
that part of the body in which is located the brain, that 
splendid organ which sets us off as superior to all other species. 
The Continuance of Mutations. You have already 
learned that man as a species first must have made his ap- 
pearance through the same tendency to vary that charac- 
terizes other species of animals, and that the particular vari- 
ation or mutation which gave man his start was the sudden 
appearance of a larger brain than his ancestors had. As- 
sociated with the developing brain must have been the grad- 
ual assumption of the erect posture. In the long ages that 
followed man’s first appearance, and his migrations here and 
there, other mutations as they appeared would meet vary- 
ing degrees of encouragement or discouragement in the en- 
vironment. Considerable differences gradually developed 
and became permanent, and different species were estab- 
lished. The Neanderthal man was one of these. But his 
species as well as others related to him were finally exter- 
minated for reasons which we cannot guess (possibly our 
own species had something to do with it), and the one species 
to which we belong became the sole human species. It is 
certain that the differences between races of mankind to-day 
which seem considerable to us are slight indeed in compari- 
son with the many differences between any of us and the 
Neanderthal man. 
Prince Kropotkin, a Russian scientist and publicist, has 
called attention to a factor in evolution which he claims is 
of vast help to every species which lives in groups. For 
example, a herd of deer, a drove of wild horses, a band of 
wolves, aid one another by being together. Likewise, man 
must have found the companionship of his fellowmen not 
only agreeable as he does to-day, but he must also have 166 
IT FROM SAVAGERY 
found it advantageous both for purposes of offense and 
defense. In this way we can see how tribes would be formed, 
why caves would be used, why crude encampments should 
be made, why villages should be established, why these 
should be provided with means of defense, and finally why 
nations of people should develop. 
The Relation of Progress to Food Supply. Professor 
Haddon has called attention to the fact that when a nation 
Fig. 88. Immigrants Entering America. 
(© Keystone View Co., Inc., New York.) 
becomes numerous its food supply tends to run short. This 
must have happened very often with prehistoric peoples, 
because they had no commerce by means of which they 
might have exchanged things they had in abundance for 
the things they needed more. You may recall that in the 
chapter on the grasshopper it was stated that the fields of 
Kansas and other western states were overrun by these 
insects because there wrere too many grasshoppers at home 
for the food in existence there. Numerous interesting paral- UP AND DOWN PHASES IN CIVILIZATION 
167 
lels are to be found in the history of man himself, not only 
in the migrations of men in prehistoric times, but even to 
recent times when the impoverished immigrants from Europe 
and Asia flocked to America in millions every decade. 
The Up and Down Phases in Civilization. One important 
difference to be noted in the comparison of insects and man 
in their relation to the rest of the world is that when man 
pours into an alien land he may temporarily destroy the 
evidences of civilization; but if he remains he appears not 
only to revive the stock of a declining race, but he even civil- 
izes himself, no matter whether his motive in coming was 
to obtain food or merely to rob. To be sure, the nation may 
fall ultimately, as was the fate of Greece and Rome. But 
such catastrophes are merely the outcome of experiments 
in race development which did not succeed; they do not 
affect the physical character of the people. The brain which 
made man different from other animals makes it possible for 
him to experiment, and through experimenting to learn. 
Bees have a more exact industrial system and form of govern- 
ment than we do, but they do not experiment, and hence 
do not learn. 
As thinking animals, constantly trying new things and 
remembering what succeeds and what does not, our race 
has learned much and has built up a marvelously complex 
civilization, part of which occasionally we have to tear 
down and rebuild because of new things we have learned. 
If sometimes men fear to tear down for lack of knowing 
what to build instead, it may indicate that the race needs 
a more far-seeing brain. 
From the years 1914 to 1918 the world passed through 
the fearful experience of a universal war. War, indeed, is 
so common in animal life that heretofore it has appeared 
to man to be a necessity in his own affairs. Nations have 
been built because of war; they have also fallen because 168 
UP FROM SAVAGERY 
of it. But the strong have given the needed new life. Strong 
men have risen to control their fellows, and to organize the 
general energy of nations and to make them productive 
in every line of human activity. Some of the strong men 
have become the kings of governments; others have become 
kings of industry, or kings of wealth. The world is organ- 
ized and is producing as never before. The World War was 
a well-nigh irresistible effort to still further organize and 
control the energies of men. 
But while the great experiment in energy-control of the 
race has been going on, new ideas have been growing and 
making ready to burst forth from the pulsing brain of man. 
The essence of one of the most important of these ideas is 
that Mankind must be freed from the domination of the 
strong, for nothing is clearer than that the strong are lead- 
ing on to destruction, probaby to self-destruction. Gradu- 
ally we are coming to see that the factor of mutual aid which 
was pointed out by Prince Kropotkin has not been allowed 
to act for the human race as a whole, but only for a limited 
portion of it. 
If, as one of the results of the World War the kings of the 
earth are compelled to release their hold on the rest of man- 
kind, we may look forward to the era when not only the 
physical energies of man shall be free, but their minds as 
well shall be free. 
The Human Brain, the Leader and the Hinderer. 
Scientific students of human culture (ethnology) generally 
agree that the human brain considered simply as an effec- 
tive organ has not improved within historic times, probably 
not since Neolithic times. This statement at first may 
seem unbelievable, for is not our entire social system, es- 
pecially that part of it connected with education, based on 
the understanding that the brain is improved by studying 
and by knowing? “Surely,” we say, ‘“history is the record THE HUMAN BRAIN 
169 
of the increasing power of the mind of man.’” It is true 
that man has made marvelous strides. He has gone into 
the unexplored parts of the world, conquered the savage 
peoples, and made the new countries yield their resources 
to the betterment of the more powerful people, though in 
doing so he has destroyed the former possessors and lost 
many of the best men of the superior race. Man has met 
the needs of commercial expansion by inventing efficient 
means of transportation and communication, ships, engines, 
railroads, automobiles, airplanes, the telegraph, the tele- 
phone; but he has also invented implements of warfare and 
death-dealing munitions, partly to defend the wealth he has 
already amassed through commerce and industry, and it is 
to be feared sometimes to extend the range of his commer- 
cial and industrial supremacy to lands controlled by other 
peoples, strangely considered his enemies. 
Man has applied the scientific discoveries of his own 
mind until he seems only at the beginning of wThat he may 
do in commanding the resources of nature. The mountains 
and the streams have been made to give up their wealth of 
metal and precious stones with ease and profit. Knowl- 
edge of the chemistry of the soil has made it possible to 
obtain greater and greater yields of plant products, and 
the food of the world has grown in quantity and has im- 
proved in quality. The desert itself has been watered and 
made to produce through engineering feats in irrigation. 
The animal life of the world has been levied upon to yield 
food, clothing, and the luxuries of ornamentation. Inven- 
tions in industry have lead to the construction of millions 
of factories, the like of which did not exist even a century 
ago. In some of these factories the crude materials of food 
are prepared for the markets of the world. In others the 
materials for clothing are manufactured. In still others, 
the machinery is produced to be used to produce more min- 
eral wealth, more plants from the soil, more food from plant 170 
UP FROM SAVAGERY 
and animal products, besides all the machinery needed to 
transport and to dispose of the countless products of man’s 
industry. Yet with all our industry, many of those who 
help to carry it on have little enough to eat and to wear, 
and young children are compelled to labor in the factories 
and in the mines. 
“But certainly,” we might say,” “the artistic, literary, 
and the scientific products of the mind of man should be 
abundant proof that his brain has improved.” Although 
our paleolithic forefathers left the evidence that some of 
them knew how to draw and to paint, it is true they do not 
seem to have left a literature, or many traces of having 
made scientific discoveries. But perhaps we have already 
done the best we could with the brains we have in painting, 
sculpture, poetry, and story. There are many wise persons 
in the world to-day who think so. On the other hand, we 
seem still to be going ahead in scientific discovery. But 
whether we have a growing mind for continuing to do it 
is another question. 
How the World Grows Better. Ethnologists have a 
way of explaining the situation created by the growth of 
human achievements by human beings who themselves 
show few signs of improvement. Whatever one generation 
accomplishes is passed down to the next, not through the 
physical inheritance of persons, but by word of mouth, by 
written or printed records, by pictures, by statuary, by 
buildings, by machinery, by countless inventions and con- 
trivances for doing things. In the course of centuries the 
things our race has learned how to do and to pass on, the 
ideas our experience has developed, the ideals toward which 
we may be striving, all form portions of a very complex 
civilization. The next generation of Americans, as wrell as 
the next generation of all other nationalities, may learn 
what has been done by the usual method,—communication. BETTER BRAINS OUR GREAT NEED 
171 
There is no evidence of a scientific nature showing that 
because our ancestors for a great many generations have 
known how to walk that we learn to walk any earlier or any 
more easily. Neither does talking come any easier by reason 
of the experience of those who have done it before us. 
Another way of considering civilization in relation to the 
matter of inheritance is to regard it as part of our environ- 
ment,—that portion which has been created by human effort 
and set about us just as definitely as we surround ourselves 
with plants and animals, food, clothing, and other factors 
which affect us materially. The human being of a new gener- 
ation simply finds himself in the midst of all these things. 
In some measure he may learn how to relate himself to many 
of them a little more satisfactorily than did his ancestors; 
if so, then we can say that our methods of teaching the 
young have improved. Let us hope they have. 
Civilization and Education.——It is through education, 
by the way, that either in school or out of it in the school 
of life, we bring the accomplishments of civilization to the 
minds of the young. Practically the race derives a great 
deal of benefit from the academic and apprentice education 
of the young, first because the continuous growth of civiliza- 
tion is thus insured, and second, because the individual 
development of the learner to the full extent of his inherited 
qualities is provided for. In these two directions we have 
abundant reason for education, and also for improving edu- 
cation. But we cannot make better brains by that method. 
Better Brains Our Great Need. Perhaps it did not 
occur to our ancestors that the human race is in need of 
more perfect brains, as it occurs to us to-day. The reasons 
for our greater interest in the matter may be explained by 
our coming to realize that man has built up a civilization 
that is almost too complex for him to comprehend, a eivili- 172 
UP FROM SAVAGERY 
zation involving incidentally some elements of injustice 
and self-destruction, and almost too big and overwhelming 
for him to direct into lines of profitable development. When 
our leading thinkers came to realize this, they began to 
analyze the factors in our civilization to see where we stand. 
It will be worth our while to go over the points briefly here. 
(1) As soon as civilization began, we started to put a 
check on the operation of natural selection which in a state 
of nature allows the weakest to be destroyed. This check 
was necessary in a measure, for it was a part of our develop- 
ing moral sense. The race did not know how to avoid lower- 
ing its quality, if indeed, it knew anything about quality 
at that time. It was interested in making war and in over- 
coming other groups of the species. 
(2) No species has ever shown the ferocity in making 
war upon itself that ours has shown. Long and frequent 
wars take heavy toll from the best manhood of the nations, 
and tend to destroy the stock from which the best manhood 
comes. The weak are never destroyed by war, for they 
are not picked to fight. 
(3) The strong members of our species have long taken 
advantage of their opportunities to control the energies 
of their fellowmen, and to gain enormous fortunes by virtue 
of that control. An important result has been that many 
millions of persons have had too little to eat, and too few 
of the conditions of environment that would have developed 
their minds and their bodies to their full capacities. 
(4) Conditions of luxury as well as conditions of poverty, 
both the results of our present day civilization, have weak- 
ened the natural bodily resistance of man, and offered lurk- 
ing places to disease and death. 
(5) There are fewer and fewer children born into families 
where the parents are intelligent and physically strong, 
partly because of the increasing cost of living, and partly 
because of numerous social exactions. MENDING THE RACE 
173 
(6) Because of ignorance, or because of indifference to 
the economic responsibility involved, there is constantly 
a large number of children born into families where the par- 
ents are poverty-stricken, or mentally enfeebled. The 
result is an increasing pre- 
ponderance of persons liv- 
ing in bad conditions, as 
well as of persons mentally 
unfit. 
(7) A great number of 
mentally well-endowed per- 
sons in the professions do 
not marry and become par- 
ents because of officially- 
imposed, or of self-imposed, 
restrictions upon marriage. 
Our Crude Beginnings in 
Mending the Race. 
Long before the factors 
here indicated had been 
considered by anyone, so- 
ciety was attempting by 
one means or another to 
correct the ills it knew to 
be in existence. We have 
had charity always, and 
within the present genera- 
tion many organizations 
that have given out food, 
clothing, and money in a 
systematic fashion. But 
many of those benefited belong to the mentally defective 
class, and would never learn to be self-dependent. 
For a still longer time than we have had charity organi- 
Fig. 89. A Feeble-Minded Man. 
Type of feeble-minded person called a 
“cretin.” Age, 31; height 4' 4”; 
weight 139 pounds; mental age 7 
years; able to read and write a little. 
Inmate of Rome State School (N. 
Y.). (Courtesy of Dr. Charles Bern- 
stein, Superintendent, Rome State 
School.) 174 
UP FROM SAVAGERY 
zations we have liad insane asylums. In these institutions 
hundreds of unfortunates are confined temporarily or per- 
manently in every state in the Union. In some of the states 
there are special asylums for the feeble-minded, where the 
attempt is made to have the inmates do simple work, per- 
manently separated from society. But there are thousands 
of feeble-minded persons going about freely, never being put 
under control until they commit a crime. If the crime is 
serious, they are sent to the penitentiary for a term, and at 
the end of it turned loose to commit other crimes, later re- 
turning to prison again. 
A very large percentage of the inmates of states’ prisons 
are really feeble-minded. Hence these unfortunates are 
not responsible for their acts. In our crude methods of ad- 
ministering justice we take revenge on these irresponsible 
criminals, and after the punishment turn them loose possibly 
to become the parents of still other irresponsible beings. 
Through education society has been trying to meet and 
solve the problems connected with the preparation of the 
young for life. Possibly in some respects we may have ex- 
pected more from education than it could accomplish. We 
have expected it to improve the stock of the race, when that 
is not possible. We have tried to give everyone the same 
preparation for life by having them study the same things, 
but we have found that method to be limited in its usefulness. 
A New Ideal for the Future.——One of the most important 
ideals now in the minds of the leading scientists, philoso- 
phers and statesmen of the enlightened countries of the world 
is the ideal of Social Control. The conviction is spreading 
that we have allowed our social matters to “go at loose ends” 
long enough, and now we should take hold and manage them 
and turn them in the proper direction. In 1875 Sir Francis 
Galton proposed the name of a new science called Eugen- 
ics which means “relating to being well-born.” As the A NEW IDEAL FOR THE FUTURE 
175 
direct result of the studies Galton made and published 
the new science attracted many students. So important 
did the subject-matter of Eugenics appear to the leading 
men of England that organizations were formed to promote 
further study and observation, and later to make the facts 
known generally throughout the United Kingdom. States- 
men knew that the quality of the English people was in dan- 
ger of deteriorating, be- 
cause of the rapid in- 
crease of the mentally 
unfit — a very serious 
matter to a nation 
threatened continually 
with international trou- 
ble. When the final ac- 
counting was made of 
the losses of the World 
War, England and all 
other nations involved in 
the struggle realized that 
serious inroads had been 
made upon the most 
valuable resource they 
possess — their young 
manhood. But their 
mentally unfit are still 
with them. The revita- 
lizing of the people of the warring nations is a far more se- 
rious problem than is the recovery from financial losses. A 
young man dead is gone forever, and with him the possibil- 
ity of future men and women as descendants. But ten thou- 
sand dollars, which has been estimated to be the liberal 
money equivalent of a human life, may be earned back with 
comparative ease millions of times over by a working nation. 
With us in America the problem of guarding and improv- 
Fig. 90. A Young Soldier. 
(Courtesy of Wide World Photos.) 176 
UP FROM SAVAGERY 
ing the quality of our racial 
inheritance is not yet recog- 
nized generally by our citi- 
zens as being serious. At the 
same time we have organiza- 
tions of scientists that are 
engaged in the collection ol 
data and the dissemination 
of information through pub- 
lications of various kinds. II 
you watch the magazines and 
in the magazine sections ol 
great newspapers you will see 
that the intelligent portion ol 
our country’s citizens are be- 
ing supplied with the facts concerning heredity and with 
suggestions for future application to situations that exist 
everywhere in our land. 
At Cold Spring Harbor, 
Long Island, New York, there 
is a laboratory for the exclu- 
sive study of Eugenics. In- 
vestigators are sent out to 
study the history of families 
in which defective traits, as 
well as those of excellent 
quality, are made available 
for examination. Some of 
these families possessing de- 
fective traits have been found 
to have numerous members 
in public institutions, such 
as asylums, poor houses, and 
prisons. Other families possessing excellent traits have had 
representatives occupying many positions of honor and 
Fig. 91. Jonathan Edwards. 
(From a Print.) 
Fig. 92. John Adams. 
(From a Print.) A NEW IDEAL FOR THE FUTURE 
177 
trust. We have many families in America who claim that 
their ancestors “came over in the Mayflower” just as in 
England large numbers “came over with William, the Con- 
queror.” Perhaps it would be of more consequence if they 
could boast that “our family came over with physically 
strong and morally clean bodies, and with a superior quality 
of brains in our heads.” 
Two valuable and well-known families in America are those 
of the great preacher, Jonathan Edwards, and of the second 
President of the country, John Adams. On the other hand, 
we have the unfortunate “Jukes” family, that in several 
generations has supplied the penal institutions of the State 
of New York with many of their inmates, and the “Kallikak” 
family, the history of which has been studied scientifically 
at the institution for the feeble-minded at Vineland, New 
Jersey. In the Catskill Mountains where this chapter is 
being written, the author knows of several “native” fami- 
lies whose members are known as being “a little off in the 
head.” Some have been away in prison for stealing; a con- 
siderable number have been taken to the asylum; many 
are shiftless and irresponsible. But most of them have chil- 
dren who in accordance with findings based on similar cases 
studied at the Eugenics Laboratory at Cold Spring Har- 
bor are absolutely certain either to show the defective 
characters themselves, or to carry them on to their descend- 
ants, or to show defective characters as well as to transmit 
them. 
The laws of inheritance have been quite elaborately 
worked out. The observations upon which they are based 
were made upon plants and upon several species of animals, 
among them insects, birds, and mammals. The most impor- 
tant of these laws is called Mendel’s Law, which was discov- 
ered by an Austrian Monk, Gregor Mendel, about 1865. The 
observations referred to very briefly here will be explained 
in the next chapter, in connection with the account of domes- 178 
UP FROM SAVAGERY 
ticated animals. Reference will then be made to the light 
Mendel’s Law throws on inheritance in man. 
Social Control of Inheritance. Enough is clear now, 
however, to show why our interest in inheritance should 
carry us to the point of deciding on some protective meas- 
ures. In other words, society must soon begin to exercise 
some form of Social Control over inheritance. 
We have long had laws forbidding the marriage of im- 
becile-minded persons, but imbeciles have no regard for law, 
and often become the parents of children out of wedlock. 
The only effective measure which is also humane is to limit 
the freedom of persons in whose blood there is proven to be 
the strain of inherited insanity or feeble-mindedness, and 
to permit them to work in small, controlled communities 
where they may be as happy and as useful as possible, but 
to prevent them absolutely from having offspring. We now 
have many laws designed to carry out this purpose, but they 
are not yet working effectively; and until they do work on 
a large scale they and our immigration laws, which touch 
the same problem, will not bring about the end desired. 
When we get rid of our injurious strains of humanity, 
they will no longer dominate the healthy strains as they do 
invariably when feeble-minded persons marry into normal 
families. And the normal persons and the possessors of 
unusual traits will be free to show whatever favorable mu- 
tations appear in them. 
Social Control Over Conditions. Just as we learned 
in considering the outcome of mutations among the lower 
animals, so in man there must be an environment favorable 
to a mutation. Otherwise discouragement and final elimima- 
tion are liable to result. For that reason it becomes a mat- 
ter of much practical importance to see to it that our own 
species exercises the necessary social control to create the SOCIAL CONTROL OVER CONDITIONS 
179 
favoring environment. When we come to think of it, we are 
more fortunately situated in this regard than is any other 
species, for we have the intelligence and the power to really 
make our surroundings what we want them to be, not each 
person for himself, of course, but the race of civilized man- 
kind for every individual member of the race. We can do 
it if we will. The leaders who have been working along the 
line of eugenics have kept this point in mind, and in sympa- 
thy with others vitally interested in the welfare of man have 
developed a sister science called Euthenics. This is the 
science of “being well-cared for.” 
When we get well under way in acting in accordance with 
the principles of Euthenics, our customs of dealing with 
ourselves and with other persons will show extensive modi- 
fications. We shall no longer slay one another in battle. We 
shall no longer grab the lion’s share of every commercial or 
industrial opportunity, or if we do, there will be enough 
others who care for the rights of all to make us drop it. We 
shall no longer deprive those who work of their share of the 
results of their own efforts, and we shall make it a crime to 
force or to permit the children to work to make up for what 
their parents do not get. 
We shall know the causes of disease and other factors 
that operate to weaken and destroy the bodies of our people, 
and then we shall eliminate the causes, and give the opportu- 
nity to bodies and minds to produce their best. We shall 
know the normal processes by which the organs of the hu- 
man body do their work, and the food and other conditions 
that keep them in health and effectiveness. 
We shall learn to care for the children from birth, for in 
them is the great hope of the future. We shall learn to save 
their lives, knowing that we have permitted only the best 
to come into existence at all. 
Finally, we shall gradually revise our system of education, 
and with intelligence really prepare the young for happy 180 
UP FROM SAVAGERY 
and efficient living by finding out what manner of mind na- 
ture has given each, and training them accordingly. We 
shall not try to make them equal by presenting to their minds 
the same ideas and the same experience, for the children 
themselves are not equal. But we shall adapt our presenta- 
tion of experiences and ideas to their capacities to under- 
stand and to enjoy, for there shall be equal opportunity, 
not equal power, for all to understand and to enjoy the heri- 
tage of the race. CHAPTER XVI 
DOMESTICATED ANIMALS; AND MENDEL’S LAW 
OF HEREDITY 
Introduction. Certainly since the early Neolithic Age, 
and possibly since the late Paleolithic Age, man has asso- 
ciated with himself various species of animals. Probably 
the dog was the first of these. But it was not as companion, 
but rather as reserve food supply, that the dog and other 
species were held by their master, man. The cave men would 
have the greater facilities for holding their captive animals 
than would those who lived in primitive shelters in the open. 
We can easily picture to ourselves those early experiments 
in capturing and holding for use the members of the species 
that were small enough to be captured by the means then 
available, and tractable enough to be kept and made to obey 
the will of man. 
Whatever species man may have tried to dominate, it is 
interesting to note that the species that have yielded domes- 
ticated animals permanently are limited practically to two 
zoological classes, the mammals and the birds. On the score 
of intelligence and adaptability to altered circumstances the 
mammals are, of course, superior to any other class. But it 
does not follow that the most intelligent of the mammals 
would prove to be the best domesticated animals. In fact, 
horses, cattle and pigs are not noted for their intelligence, 
though they are among the most valuable of our domesti- 
cated species. And the wolves, remarkable for their intelli- 
gence, cannot be domesticated at all. The birds would not be 
considered intelligent as a class, or by single species; but they 
are more intelligent than the next class below, the reptiles. 
181 182 
DOMESTICATED ANIMALS 
Darwin called attention to the great differences between 
the various kinds of pigeons, and said that if pigeons were 
found living in a state of nature, they would most certainly 
be thought to belong to different species. As a matter of 
fact, all pigeons belong to one species, and are technically 
called varieties of the common rock dove, a European species. 
The same explanation applies to all our domesticated ani- 
mals, with the possible exception of the dog. The ancestry 
of the dog is still an unsolved problem. 
The Horse. At the close of the detailed history of the 
evolution of the horse given in Chapter XIV it was stated 
that our present-day domesticated horses belong to one 
species. However, there appears to be at least one other 
species of horse living wild to-day whose line of traceable 
ancestry runs back practically unbroken into the Paleo- 
lithic Age; for, sketches in the caves have been found show- 
ing a horse closely allied to the wild tarpan which now lives 
in Western Mongolia. The tarpan is a small horse, practi- 
cally a pony, with a big head and relatively slender legs. 
It is four feet (twelve hands) high, with a short erect mane, is 
dun in color, with a narrow stripe down the spine, a verti- 
cal stripe running down each shoulder and faint bars across 
the upper part of each leg. The colts can be captured and 
tamed, but the adults are untamable. 
The several varities or breeds of our domestic horse seem 
more closely allied to a certain wild horse ranging the forests 
of Russia, Poland, Germany, and France until quite late in 
the Christian Era. These wild horses were mouse-colored, 
with a dark streak along the spine, and with dark mane and 
tail. The description exactly coincides with the so-called mus- 
tang of Texas, an American wild horse. The European wild 
horse was untamable, except as a colt. This horse was 
hunted for its flesh and for the skins. 
The picture of the skeleton of the horse given in Figure 93 THE HORSE 
183 
is meant to serve the double purpose of showing the frame- 
work of the present day horse and of offering the oppor- 
Fig. 93. Skeletons of Horse and Man. 
(Courtesy of American Museum of Natural History.) 
tunity for a comparison with the skeleton of man. The 
fore-legs of the horse correspond to the arms of man. The 184 
DOMESTICATED ANIMALS 
upper arm bone in the horse is short, and lies close against 
the body; the elbow lies about even with the under surface 
of its body. The two fore-arm bones are differently formed 
from the same bones in man, but their relative position is 
the same. The most striking difference is in the region 
corresponding to our wrist. In the horse the wrist begins 
at the so-called “knee” and extends to the fetlock. The 
main bone there is the heavy “cannon-bone”; it is borne 
company by the two “splint” bones, which are the relics 
of the bones that were connected with the ancestral toes. 
The remainder of the fore-legs are the single series of toe 
bones and the toe-nail or the hoof. 
The modification of structure that occurred in the wrist 
of the fore-leg takes place in the ankle of the hind legs; 
but the high-standing “hock” (the heel) is more conspicu- 
ous than the corresponding point in the fore-legs. The real 
knee of the horse is much higher relatively than in man; 
it occurs in the flank of the horse. The comparison of the 
other bones of the horse and of man may be made easily, 
region by region. 
Horses like persons, and most other mammals as well, 
have two sets of teeth, a baby or milk set and a permanent 
set. By the time the young horse is three years old its baby 
teeth begin to be replaced with permanent teeth which are 
larger. The substitution begins with the front teeth, called 
first incisors, and proceeds backward. At three and one- 
half years to four years the second pair of incisors in upper 
and lower jaws have pushed out their milk teeth, and at 
five years the third and last pair of incisors come in. At 
about the age of four or four and one-half in the stallion or 
male four tusks or canine teeth appear above and below in 
the long space between the incisors and the cheek teeth. 
The incisors have curious pits or “marks” three-quarters 
of an inch deep from the top of the crown when these teeth 
are first protruded. As the teeth wear down, the pits dis- THE HORSE 
185 
appear and incidentally aid in giving indication of the age 
of the horse. The pit disappears in the first or front pair 
of lower incisors when the horse is six years old; at seven 
the pit in the second pair of lower incisors disappears; at 
eight, in the third pair of lower incisors. In the correspond- 
ing upper teeth the pits remain about two years longer in 
each case. Thus, a horse that has no hollow depressions 
at all in the crowns of its incisors, either above or below, 
is very probably over ten years old. How much older it 
may be can only be guessed, unless the teeth are worn down 
nearly to the gums, in which case the animal would be from 
twenty to forty years of age. Forty years is an extreme 
age for horses. 
The cheek teeth are six in number on each side in each 
jaw. The first three on each side in each jaw, called pre- 
molars, have milk predecessors, but the molar teeth have 
not. This is exactly the history of our own teeth, except 
that we have but two premolars for the three in the horse. 
The enamel in the teeth of horses runs in convolutions through 
the softer dentine, instead of lying outside as with our teeth. 
The exterior of the horse’s body is quite well known to 
everyone, except possibly the significance of the “chest- 
nuts” or hard wart-like growths on the fore-legs and the 
hind legs. These are supposed to be degenerate scent glands, 
the like of which are found in many other gregarious mam- 
mals, as for example in the deer family. These scent glands 
in nature yield a secretion which has a strong odor that is 
carried a long distance on the wind, serving the species by 
enabling individuals to find one another. The fetlocks of 
a horse, the thick tufts of hair near the hoof, surround a re- 
minder of the evolution of the race. This is the “ergot”, 
a small hairless pad wdiich is the ancestral sole of the foot. 
We have in America several breeds or varieties of horses. 
Ail of them were developed in Europe, or in Asia, except 
the American wild horse. And that is the descendant of 186 
DOMESTICATED ANIMALS 
European horses brought over by the Spanish conquer- 
ors, from whom its ancestors escaped nearly four hundred 
years ago. One type of our wild horse is the mustang, 
mentioned in a previous paragraph; the other is a larger 
and more tractable type generally of bay color that until 
about the year 1880 roamed our Western Plains in large 
numbers. The breed has been nearly exterminated by cap- 
ture. The adults were captured in bands by a small group 
of men driving domesticated horses hitched to “buck- 
boards” or other light and strong vehicles. When a band 
was first discovered, it made off at great speed, under the 
leadership of the master of the band, a stallion that had won 
his place as master by conquest over other stallions. After 
reaching a distant eminence the band would turn and watch 
its pursuers with curiosity. The hunters would follow 
leisurely but persistently for a week, if necessary, camping 
whenever they themselves desired, but gradually wearing 
down the resistance and taming the wild nature of the band 
by being continually near them. At length the captives 
could be driven in the direction of a distant corral, where 
skillful cowboys, armed with lassoes completed the capture. 
The “breaking” of a wild horse to the saddle is an event 
that tries the nerves and the skill of the bravest. But when 
conquered by one ride administered by an artist in the pro- 
fession of Western horsemanship, the wild horse looks and 
acts like any other, unless it belongs to the tricky breed of 
mustang. The author in his boyhood in Western Kansas 
was the happy possessor of a wild stallion that had re- 
ceived his baptism of man-power from some one else. For 
several years this splendid creature gave daily proof by en- 
during long rides over the plains that he had won his right 
in nature to the leadership among his fellows,—a leadership 
from which only man had the intelligence and the skill to 
displace him. 
For some years it has seemed to be only a question of THE MULE 
187 
time when the automobile would eliminate the occupation 
of raising horses. No doubt the increase in the number 
of motor trucks decreases the number of Percheron or Nor- 
man horses that will be demanded as draft horses. Lim- 
ousines displace the handsome carriage horses of the city 
streets and the country estates; and the farmer’s steam- 
plows and steam threshers may mean smaller stable room 
for the horses he has left. But the uses for horses are still 
numerous, and the prices of horses are still high, which is a 
good commercial indication of their continued usefulness. 
The police department of New York City cannot obtain a 
horse suited to the needs of mounted patrol service for less 
than $375.00. Farm horses also are very expensive. There 
is every prospect that our horses will be needed for a long 
time to come, and that the breeds will be still further im- 
proved, even for racing, in spite of the fact that the pros- 
pective elimination of betting in horse-racing may seem to 
some persons to carry with it a decrease in interest in that 
branch of horse raising. 
The Mule. Mules are the progeny of a sire or father 
that is a domesticated African ass and a dam or mother 
that is a horse. The two parent animals belong to different 
species, and their progeny are called “hybrids,” the tech- 
nical term given to animals or plants that result from the 
crossing of members of different species. Sometimes hybrids 
give rise to a line of generations like themselves, but a few, 
like the mule, do not bear young. 
Mules make extremely valuable draft animals where 
heavy loads have to be taken over slippery hills or up rough 
mountain sides. They are very “sure-footed.” They appear 
to stand the rough treatment incident to work in the moun- 
tains much better than do more highly bred horses. Mules 
are not so liable to become ill from indifferent feeding, or 
to mind going long without food or water, while horses must 188 
D(IMESTIC ATED ANIMAI,S 
be fed at least three times a day, and do better with four or 
five feedings. 
Mules are supposed to be very quick-witted and tricky, 
besides being able and 
even anxious to use their 
heels to play against the 
bodies of their enemies, 
who may be any other 
creatures near at hand. 
There is very little doubt 
that mules live up to 
their reputation. For 
that reason they are less 
available for general use 
than horses are. But 
the men who manage 
mules are willing to 
match their wits against 
them, and are not averse to emphasizing their superiority 
with not a little mistreatment. 
The Ox. The technical common name for cattle is oxen. 
The two names will be used here interchangeably. 
There are no fossils of the direct ancestors of the ox in 
America, but fossil bones of the race are found in the Plio- 
cene of Asia and in the Pleistocene of Europe. According 
to the authorities on the development of the ox, the long- 
horned ox, Bos longifrons, migrated westward in Europe 
in the domesticated state with Neolithic man. The bones 
of this species are found from the polished or new stone age 
down to historic times in such places as to lead to the con- 
viction that this species is the origin of our domesticated 
type. But when descendants of the species first came to 
America they were divided into the many varieties that had 
developed under the control of the breeders. 
Fig. 94. Mule. 
(Courtesy of American Museum of Nat- 
ural History.) THE OX 
189 
As the direct result of accepting and isolating the muta- 
tions that appeared in herds of cattle, breeders in Europe 
have obtained such distinct varieties as those represented 
by the red, short-horned Durham, the red and white Here- 
ford, both famous as beef cattle, and the Alderney, and the 
Jersey, both remarkable for their milk- and butter-producing 
qualities, and also the curious hornless, Polled Angus breed. 
Fig. 95. Ancient Long-Horned Ox. 
(From Kobelt: Die Verbreitung der Tierwelt.) 
The Polled Angus began its career as a striking mutation, 
an animal being born that did not later have horns. Ex- 
perimental breeding showed that when either parent was 
hornless the offspring would also be hornless, no matter 
what might be the length of the horns of either parent. 
The characteristic of hornlessness is thus described as 
“dominant,” and the horned condition as “recessive.” 
For if the progeny of horned and hornless parents be bred 190 
DOMESTICATED ANIMALS 
together the average result of many experiments will be 
that one-fourth of the succeeding generation will have horns, 
showing that the character of having horns had not been 
eliminated but had merely receded into the background, 
so to speak; hence, the term recessive. 
If the remaining three-fourths are bred for another genera- 
tion experiments show that one-fourth on the average will 
produce hornless progeny, and so on continually. One 
fourth of each generation will have horns. If horned animals 
are bred together none but horned appear. Two-fourths 
of each generation in these experiments are hornless, but 
in them there is always a mixture of the two characters. 
These characters always separate in the next generation 
into one-fourth horned, one-fourth hornless, and two-fourths 
hornless but with mixed characters again. When a charac- 
ter is retained through an indefinite number of generations, 
the individuals possessing it are said to breed true in respect 
to that character; that is, to constitute a “pure line.” 
Thus, horned cattle always constitute a pure line, but horn- 
less cattle may be representatives of a pure line, or a mixture 
of two lines, a dominant hornless line and a recessive horned 
one. It is impossible to say in the case of any individual 
hornless ox whether it is pure or mixed, until an experiment 
in breeding from it is carried out. 
This brief account of the way the character of hornless- 
ness works out in the breeding of cattle is intended to intro- 
duce the student to an elementary understanding of the op- 
eration of Mendel’s Law of Heredity. A more complete ac- 
count will follow in a later section of this chapter, and also 
an explanation of the application of the law to inheritance 
in man. The fact that the Austrian monk, Gregor Mendel, 
first discovered the working of the law while carrying out 
experiments on the breeding of the common garden pea will 
give a suggestion of the wide range of life to which the law 
has been found to apply. THE OX 
191 
In concluding this section of the chapter the student per- 
haps does not need to be reminded of the vast economic im- 
portance of cattle to man. The beef and the leather of which 
enormous quantities are used make one of our greatest 
sources of wealth. Cattle are still raised on the plains of the 
great West, where in former times the unclaimed stretches 
of land formed the “range” over which cattle wandered and 
fed from “water hole to water hole,” being “rounded up” 
every spring for the purpose of branding the calves. Brand- 
ing the flank of a calf with a red-hot iron was the only sat- 
isfactory way of indicating the ownership of a “critter” 
(creature) after it reached the age of independence of its 
mother (at about one year or less). Every owner had his 
peculiar brand, consisting of a letter or a symbol formed out 
of iron and adjusted at the end of a rod of iron. For example, 
one mentioned in a fascinating story of the West written by 
Stewart Edward White was a capital “Y” lying on its side, 
thus, i-n . It was appropriately called the “Lazy Y” Brand, 
and so was everything connected with the ranch ownership 
of the great property of which the brand was the symbol. 
In the fall the larger animals were rounded up and usually 
shipped to some of the middle western states to be fattened 
for the market. Nowadays the range-produced cattle are 
becoming fewer on account of the range land being taken 
up in numerous small tracts by home-builders. This fact 
makes the raising of cattle for the market a more expensive 
proceeding, and doubtless has much to do with the increase 
in the cost of meat. 
Again, if you have ever watched a long milk train starting 
out late at night for a distant city, and have realized that 
many other similar trains are hurrying to cities all over the 
country, you can build up in the imagination the extent of the 
milk industry. The milk and the butter and the cheese are 
also sources of vast wealth, for the reason that they are among 
the most valuable sources of human energy when used as food. 192 
DOMESTICATED ANIMALS 
The Sheep. The sheep has no fossil remains in America, 
having made its way here only since the Pleistocene. Its 
ancestry dates back to the Miocene. 
Sheep belong to the group of ruminants with the ox and 
the deer. They are given this name on account of the pos- 
session of four sections of the stomach, one of which is called 
the rumen. The process of chewing the food until it is partly 
ground up, swallowing it, and later “unswallowing” it as 
far as the mouth to be rechewed as the “cud” is characteris- 
Fig. 96. A Valuable Wool Producer. 
(From Lydekker: The Sheep and Its Cousins.) 
tic of the sheep as it is of the ox. The number and arrange- 
ment of the teeth is exactly the same as it is in the ox, there 
being no upper incisors in either species. The skeleton is 
much the same in both. 
Sheep raising is one of the most productive industries we 
have in this country, and one in which a farmer or stock 
raiser may engage with a small capital. It should be added 
that it is also an industry in which the inexperienced may lose 
more quickly than in any other of the kind, for sheep are 
delicate animals, and also very stupid. They have little THE PIG 
193 
sense about running to shelter on the approach of a storm, 
and permit themselves to be driven away from safety and 
chilled to death in a cold rain that would not seriously af- 
fect cattle or horses. A sheep raiser to be successful must 
practically live with the animals, and must be ready on the 
earliest sign of a storm to go out and drive the herd to shel- 
ter. 
The factors that make sheep raising profitable, supposing 
that losses from storms and from diseases have been kept 
down by extraordinary care, are the facts that each ewe or 
female on maturity will have usually two lambs, and that 
each sheep yields a valuable fleece each year. As a source 
of meat supply sheep and lambs bring good prices. In primi- 
tive sheep-raising districts young men frequently make rec- 
ords of shearing eighty or more sheep in a day. 
In regions where a sheep range and a cattle range lie ad- 
jacent sheep may wander beyond their territory. If that 
happens the range is liable to be spoiled for cattle, for sheep 
feed so closely to the ground that cattle will starve if they 
depend on what the sheep leave. 
The future of sheep raising in America is secure, al- 
though not nearly so many persons raise sheep as formerly 
did. The industry is carried on by men who control large 
herds, and the production of the wool is more carefully man- 
aged than it was at one time. There is no question that man 
is able to manufacture warmer clothing from wool than he 
can make from any other raw material. The more expensive 
furs cannot compare with woolen garments in serviceable- 
ness and cleanliness. 
The Pig. The ancestry of the true pigs may be traced 
back to the Miocene period in Europe and Asia. But none 
ever visited America until after its discovery by Columbus, 
and then they were brought over. 
The ancestor of our pig is undoubtedly the wild boar of 194 
DOMESTICATED ANIMALS 
Europe, an animal that even to-day roams the forests of Ger- 
many, and was once hunted by royalty and others, not be- 
cause it is a dangerous animal (except when wounded) to be 
exterminated, but for the “sport” his pursuit afforded. 
Breeding has resulted in the production of varieties which 
reach maturity in two years, and often weigh several hundred 
pounds. 
The production of meat by way of the pig is a remarkably 
quick way of getting a supply. It has been estimated that 
Cave-Man drawing. (Courtesy of Ameriean Museum 
of Natural History.) 
Fig. 97. Wild Boar. 
within eighteen months a quantity of meat may he doubled 
by feeding pigs food that for the most part is the waste of 
the household. Although pigs may be fattened on garbage, 
it is certain that the quality of the pork may be improved by 
feeding corn or other grains. Pork is the flesh food which 
practically every farmer is able to produce for himself, and 
by “curing” keep a supply through the winter and until the 
fall, when a fresh supply is ready. However, pork is too fat 
for general use in summer weather, except as food for a man 
wTho is doing very hard work requiring a large supply of heat- THE DOC, 
195 
energy, which pork readily supplies. But it is certainly not 
suitable for young children, except in the form of thin bacon. 
The manners of pigs are proverbially bad, especially their 
table manners, which are characterized by gulping and the 
vulgar smacking of lips. These habits of pigs are objected to 
by all human beings, although imitated by some. Besides, 
pigs are not cleanly. In this particular, however, the Euro- 
pean farmers frequently seem to assume that the pig is not 
untidy because it likes it, but probably because it cannot 
help it in its customary narrow quarters. Hence, they very 
generally keep the pig pens clean and the pigs supplied with 
straw. Some of them go so far as actually to scrub the pigs 
with a scrub brush, soap and water. 
The Dog. The ancestry of the dog is known to be 
extremely ancient, extending into the dim Eocene period, 
where it developed from a stock that produced the now ex- 
tinct bear-dogs, the hyena-dogs, fox-dogs, and many others. 
More recently true types of dogs, foxes, hyenas, bears, and 
wolves developed from the complex stock. Some authori- 
ties believe that our many varieties of dog originated from 
wolves in different parts of the world. Others claim that the 
immediate wild ancestor of the dog is extinct. There seems 
to be considerable justification for the latter point of view, 
which was held by the late Professor Shaler, of Harvard 
University, an authority on dogs as well as a great lover of 
them. Two bits of evidence important in this connection 
are the facts that dogs have never been known to revert to 
the wild state, showing that their captivity must be very 
ancient, and wolves have never been domesticated. 
There is good reason to believe that dogs were the first 
domesticated animals of man. At first, however, they served 
the function of a reserve food supply. But man must soon 
have made use of their racial capacity to hunt, run down and 
capture prey. Very likely the dogs had to be trained per- 196 
DOMESTICATED ANIMALS 
petually to “retrieve” or to return to the master the prey they 
had captured, for that quality needs to be emphasized in the 
training of dogs even to this day, except in certain remark- 
able cases where, as in the shepherd dog, retrieving sheep 
and returning them unharmed to the master lias become in- 
grained in the breed. 
Somewhere in the development of dogs from their wild 
ancestors they became the companions of man in a more 
intimate way than have any other species. Professor Shaler 
thinks man’s first use of the dog was as a companion, but 
this seems hardly likely, since companionship comes usually 
after intimate acquaintance. At whatever time the tendency 
to friendliness and loyalty to a master developed as a mu- 
tation, certainly the selective breeding carried on has fixed the 
characters indelibly as a part of the emotional nature of dogs. 
In the early history of the breeding of dogs, we may easily 
suppose that an important purpose must have been the use 
of the animals as aids in hunting. Besides loyalty and faith- 
fulness the owners must have realized the need of a certain 
amount of intelligence in dogs. Mutations in this direction 
would be seized upon and emphasized in the breeding. Thus 
acts which at first would be original and unusual, by selec- 
tive breeding would become fixed, if the character were of a 
dominant type. Inherited tendencies to act in a given way 
are called instinctive. 
In the early days of the study of animal psychology it was 
customary to assert that the animals lower than man do not 
manifest intelligence, but acted always from instinct, that 
is, without understanding and without reason. We now 
realize that instinctive acts must have arisen as original ex- 
periences from mental mutations of as definite a character 
as the mutations of structure or of color of hair or skin. The 
real distinction between the mentality of an animal lower 
than man and man himself is more accurately made by call- 
ing the difference one of degree rather than one of kind. That THE DOG 
197 
is to say, the range of ability to think, to reason what should 
be done in a given situation of a new or unusual nature is 
much lower than it is in man. However, if we were entirely 
without prejudice we might be willing to grant the possi- 
bility that some dogs really think effectively under unusual 
circumstances, if we should see one tuffffins at the coat of 
his master and indicating 
by short excursions in a 
given direction that some 
unseen person is in dan- 
ger. And if on reaching 
the bank of the river we 
observe a person stand- 
ing there wringing his or 
her hands helplessly while 
looking at a friend strug- 
gling in the water, we 
might be forced to ac- 
knowledge considerable 
overlapping in the range 
of intelligence of four- 
legged and two-legged 
animals. But we must 
retain our loyalty to our 
own species (and also to 
our intelligence) to the 
extent of recognizing the 
fact that the height to 
which our thinking may 
attain is never approached by animals lower than man. We 
can be sure of this in spite of the fact that we understand 
little of the language of the lower animals, and we know it 
from the tangible results which our eyes can see. 
Interesting as dogs are to most persons, and willing as 
we might be that the frequent loneliness of a man or a woman 
These dogs help to distribute milk and 
other food in Belgium and Holland. 
(© Press Illustrating Service, New York.) 
Fig. 98. Dutch Dog in Harness. 198 
DOMESTICATED ANIMALS 
shall be lightened and cheered by at least one creature 
friendly to him or her, we cannot but resent the insult to our 
kind, and to dogs as well, that is implied in the nauseating 
custom of misguided persons who prefer to fondle a toy 
spaniel to holding a baby of their own. Dog dinners, dog 
birthday celebrations, and dog funerals conducted by grown 
men and women are unmistakable signs of degeneration,— 
of the persons and of the dogs. 
The Cat. The Oligoeene period in North America saw 
the beginning of the great family to which our domestic 
cat belongs. The most ferocious and terrible of them, one 
with upper canine teeth eight inches long, migrated to 
Europe and became extinct in the Pleistocene period. Most 
of the existing species of the eat family are now living in 
Africa. From one of these the domestic cat arose. The 
wild ancestor is probably the Egyptian cat, which was 
domesticated in Egypt at least 1300 years before Christ. 
Professor Mivart, of England, says, “The cat in Egypt 
was an object of religious worship, and the venerated in- 
mate of certain temples. Pasht, the Goddess of cats, was 
represented in Egypt under the Roman Empire with a cat’s 
head. Cats were embalmed and made into mummies on 
death. The cat was an emblem of the sun to the Egyptians. 
Its eyes were supposed to vary in appearance with the course 
of that luminary, and also to change with the moon; hence, 
it was also sacred to the moon.” 
In modern times there are two kinds of persons who have 
opinions about cats,—those who like them and those who 
do not. Professor Mivart, although writing a very techni- 
cal treatise on the anatomy of cats, gives them an excellent 
character. He says cats display a high order of intelligence, 
meeting new problems with considerable skill. They are 
very emotional and very expressive of their feelings by 
sounds and by gestures as well. Some other persons claim THE CHICKEN 
199 
that cats are extremely selfish, being absolutely without 
feeling except those of cruelty and a desire for a warm spot 
to comfort their lazy bodies. A few persons have such 
hatred of cats that they refuse to enter a room where one 
is suspected of being. 
Without betraying a sympathy for either side of the con- 
troversy, perhaps we may recall a few facts about cats which 
will not arouse opposition. You may carry a cat away from 
its home in a basket without its being able to see where it 
is going, and it will return to its home, which may be many 
miles distant. Cats capture mice, rats, young rabbits, 
and also birds, the latter not from sheer cruelty, but because 
the act is in accordance with their instinct to capture to 
meet their need for something to eat. Cats and dogs are 
hereditary enemies. It has been suggested that the reason 
for this is the fact that both come from families of car- 
nivorous or flesh-eating animals that lived in the same an- 
cient environment, and found themselves in sharp com- 
petition with one another. We are reasonably sure they 
did compete for a common prize, for the fossil bones of 
wolves and other dog-like creatures and tigers have been 
found near the bones of elephants, and all were trapped 
together in great tarpools where California now lies. Doubt- 
less, there are other cases of species that are hereditary 
foes for economic reasons, but we happen not to have them 
as domesticated animals. 
The Chicken. It is generally agreed that the ancestor 
of our common barnyard fowl is the wild Gallus bankiva 
of East India. The East Indian fowl is an existing species, 
and specimens of it may be seen at many zoological gardens. 
The domesticated game fowl, sometimes kept by chicken 
fanciers, and by traveling bands of gypsies as a means to 
gambling at cock-fighting, is thought to be the breed nearest 
to the wild ancestor. Fig. 99. Original Jungle Fowls and Some Descendants. THE CHICKEN 
201 
The breeding of chickens has resulted in the production 
of striking differences from the little wild game fowl. Do- 
mestic fowls may be eight to ten times heavier than their an- 
cestor, and generally lay far more eggs. The length and 
strength of the wings have not developed well; hence, 
chickens fly laboriously and with little success. The latter 
fact explains why chickens never go far from home. Al- 
though our neighbor’s chickens may fly well enough to 
enter our gardens occasionally, we may be sure their “hom- 
ing” instinct is sufficiently strong to lead them back 
where they belong, even if they do not remain there per- 
manently. 
Chicken-farming is a favorite branch of stock-raising 
with more persons who have not had previous experience 
in it than is any other branch. Although many fail at it, 
the apparent profits and the small capital necessary to make 
a start influence the inexperienced to keep on trying. The 
most general complaint heard from those who do not succeed 
at this industry is that they never thought chickens could 
eat so much. To use the common expression, “Chickens 
eat their heads off.” It is necessary therefore to reduce the 
cost of the food supplied to them. This can be done most 
satisfactorily by the chicken farmer raising it himself, thus 
saving the profit that would go otherwise to one or two 
“middlemen” who grow rich out of the needs of others. 
It is a common saying with farmers generally that the way 
to make profit out of raising grain is to feed it to hogs or to 
other animals right on the farm. This is the same as say- 
ing that the way to make money in raising farm stock 
is to reduce to the minimum the number of business 
dealings involved in producing the animals and getting 
them to the consumers. It is an important incident that 
the same policy if pursued generally would reduce the cost 
of food to the consumers themselves, and that means to 
all of us. 202 
DOMESTICATED ANIMALS 
Possible Additions to the Kinds of Domesticated Ani- 
mals. We have other birds than the chicken that have 
been brought to a state of domestication within compara- 
tively recent times, the turkey, the duck, and the goose. 
This suggests a point made by Professor Shaler in his book, 
Domesticated Animals. He calls attention to the fact that 
certain of our wild species of animals are in danger of 
being exterminated through slaughter by man, and suggests 
(Courtesy of American Museum of Natural History.) 
Fig. 100. The American Bison. 
that experiments be made in domesticating valuable wild 
species to save them from destruction. The American 
Bison, for example, might be one of these. It appears to 
be difficult to domesticate the members of this species, but 
hybrids with domestic cattle make good beef. Deer also 
might be domesticated on a larger scale than they are, and 
removed from the danger zone. The antelope referred to on 
page 126 could be domesticated without much doubt, but it 
does not breed in captivity. MENDELIAN INHERITANCE IN MAN 
203 
Among the game birds, the ruffed grouse or “red ruff” 
of literary fame might be domesticated, along with the 
several species of its near relatives now fast disappearing. 
The movement of the Audubon societies relative to pro- 
tecting the song birds is now on a sound basis. Nearly all 
intelligent persons know the economic reasons for saving 
the song birds (see p. 117). 
Mendelian Inheritance in Man. Professor Edwin G. 
Conklin, in his book, Heredity and Environment in the 
Development of Man, calls attention to the fact that the 
study of inheritance in man must always be less satisfactory 
than it is in the cases of many lower animals. This, he 
says, is because we must obtain our data by observation 
and by the tedious collection of statistics alone, whereas 
Professor Jennings, of Johns Hopkins University, can in 
two months carry an experimental lot of Paramecia (see 
p. 6) through as many generations as there have been of 
human beings in all the Christian era, which is about fifty- 
seven, counting thirty-three years as a generation. Besides, 
the number of children in a human family is so few that it 
is difficult to determine what the hereditary possibilities 
are. However, Professors Davenport and Plate have pub- 
lished data covering about sixty human traits which seem 
to be inherited according to the Mendelian principle. 
Curly hair is dominant over straight hair, in the white 
race as well as in hybrids of black and white races. Dark 
hair is dominant over light to red hair. This means that 
if either parent has curly hair or dark hair, all the children 
will have hair of the same nature. But it also means that 
on the average one-fourth of the grandchildren of curly 
and straight haired persons will have straight hair, although 
both parents will have curly hair. Similarly, one-fourth 
of the grandchildren of dark and light haired persons will 
be light haired although both parents have dark hair. If 204 
DOMESTICATED ANIMALS 
the straight haired children and the light haired children 
severally marry persons with the same kind of hair, the 
recessive straight and light hair appear in the children for as 
many generations as the line remains pure; that is, so long 
as no marriages with curly or dark haired persons take place. 
A dark skin is dominant over a light skin, and a skin of 
normal color, light or dark, is dominant over the character 
of albinism. As you may know, once in awhile a child with 
white hair and pink eyes, like those of the white rabbit, 
will be born into a family where the parents both have skin 
and eyes apparently of the normal appearance. This means 
that both parents have in their bodies the character of albin- 
ism as a recessive character. The children received albinism 
as their share of the algebraic formula given in Chapter 
XXXIX. Of the remaining children of such marriages one- 
third on the average (one-fourth of the entire number) are of 
normal color and always have children of the normal color, 
and two-thirds (two fourths of the entire number) will appear 
to be normal but in reality are mixed dominant and recessive 
with reference to the character of albinism. But it is impos- 
sible to tell which are pure and which are mixed until their 
children are born. When born, their children separate into 
the same classes as the preceding generation of mixed lines. 
A nervous temperament is dominant over a phlegmatic 
temperament. The character of average intellectual ca- 
pacity is dominant over the character of very great intellec- 
tual capacity and also over the character of very small in- 
tellectual capacity. Thus if a person of average intellectual 
capacity had married into the family of Jonathan Edwards 
(p. 177) that would have tended to establish a branch of 
the family that would be permanently average in intellect 
(one-fourth of the descendants), double the number who 
themselves would be average but capable of having one- 
fourth of their children of great intellectual capacity (see 
Table, p. 205, and finally, one-fourth who might reestab- MENDELIAN INHERITANCE IN MAN 
205 
TABLE OF INHERITED QUALITIES 
Mendelian Inheritance in Man 
Dominant 
Hair 
Curly 
Dark 
Eye Color 
Brown 
Skin Color 
Dark 
Normal Pigmentation 
Countenance 
Hapsburg Type (thick lower lip 
and prominent chin) 
German Type 
Temperament 
Nervous 
Intellectual Capacity 
Average 
Average 
Normal Characters 
Recessive 
Straight 
Light to red 
Blue 
Light 
Albinism (absence of pigment) 
Normal 
Jewish Type 
Phlegmatic 
Very great 
Very small 
Nervous System 
Normal Condition 
Pathological Characters 
Hereditary Epilepsy 
Heredity Feeble-mindedness 
Hereditary Insanity 
Hereditary Alcoholism 
Hereditary Criminality 
Hereditary Hysteria 
St. Vitus’ Dance 
Deaf-mutism 
Normal 
Normal 
Ears 
Normal 
Eyes 
Hereditary Cataract 
Pigmentary Degeneration 
lish after the second generation a line of persons of great 
intellect. 
There are many abnormal characters which operate in 
inheritance according to the Mendelian principle. These 206 
DOMESTICATED ANIMALS 
characters are easily followed because of their unusual 
nature. For example, there are persons who lack one joint 
in each finger and toe. This character of short-fingeredness 
is dominant over the normal hand. Webbed fingers will 
tend to obliterate the normal separateness of fingers, and 
persons with six fingers and six toes tend to increase the 
proportions of persons in a given community who have the 
abnormal number. Such a community has actually been 
discovered. 
Various hereditary diseases of the nervous system have 
been found to be recessive with respect to the character. 
Among these are epilepsy, feeble-mindedness, insanity, 
alcoholism, criminality, hysteria, and St. Vitus’ Dance. 
It is the knowledge of the way Mendel’s Law operates in 
the cases of these diseases that gives to individuals and to 
states the basis for any course of action they may decide 
to take. Mental heredity has always been considered the 
most elusive, as well as the most important to be considered, 
although certain hereditary diseases of the eyes like cata- 
ract become important in that they are transmitted as 
dominant characters. 
The nervous abnormalities, though recessive, involve 
the race in untold but avoidable miseries. A conscientious 
person who finds himself or herself in love with a person 
in whose family there is a strain of insanity will face the 
situation calmly, and calculate the chances from marriage. 
Such a person will see after studying the data contained 
in the Table that a young man or woman may be mentally 
normal to all appearances and still carry germ cells in which 
reside the recessive character of insanity, provided of course, 
one of the parents has been afflicted with hereditary insanity. 
Insanity that results from mental stress in a single genera- 
tion is not inherited. The mathematical chances with refer- 
ence to the children of parents of whom one has hereditary 
insanity, not showing, are different from those cases in which MENDELIAN INHERITANCE IN MAN 
207 
both parents are descended from strains bearing insanity. 
According to the rule as worked out by Mendel and others 
none of the children in the former case would be insane. 
But the fact that the insane strain is still present is shown 
by the formula: 
Male germ cells Healthy Healthy 
I \ / I 
XXX 
I / \ I 
Female germ cells Healthy Insane 
The possible combinations would give two healthy children 
and two healthy (insane) children. That is to say, in a 
large number of such cases all the children would apparently 
be healthy, but one-half of them would bear the strain of 
insanity in them. If children of such parentage always 
married into families free from the diseased strain, insanity 
would never make its appearance there. But if one bear- 
ing the recessive strain of insanity should marry a person 
who also bore the insane character in recessive form, one- 
fourth of their children on the average would surely be in- 
sane, and one-half would bear the insane strain in recessive 
form. Only one-fourth would be free from the dread catas- 
trophe. 
If you consider these matters thoughtfully when you are 
young you will be surer of the happiness of adult life that 
is due you. CHAPTER XVII 
THE ENVIRONMENT OF PLANTS AND ANIMALS 
Man and other animals go about in their environment 
drawing from it their supplies for existence. Those more 
familiar to us breathe the air, they drink the water, they re- 
main near home in bad weather, and go farther afield in good 
weather. The common activities of animals are related to 
the problems of securing food and avoiding enemies. 
Plants appear to have habits contrary to those of animals. 
This appearance is due to the stationary position of the large 
well-known plants. A more complete comparison of plants 
and animals will appear in later chapters than is necessary" 
in a preliminary discussion. The more obvious facts can be 
given here. 
Plants and animals are invariably associated; that is to 
say, neither plants nor animals exist alone. Sometimes we 
are able to discover some helpful relation between the two, 
but more often a great many kinds of animals live in a given 
environment in company with a great many kinds of plants, 
and in relations that are vague and seemingly unimportant. 
This appearance of vagueness of relation is in part due to 
the fact that many species of plants and animals actually do 
occupy little “corners of existence,’’ so to speak, having 
slight concern with other creatures. In large part the 
familiar species of plants and animals distribute their de- 
pendence among a multitude of incidents in nature. But any 
of us may come into contact with definite examples of de- 
pendencies or interrelations. 
Let us first realize that all living things breathe. One of 
the essential facts in the process of breathing is that air is 
drawn into the body of the plant or animal, and the oxygen 
208 ENVIRONMENT OF PLANTS AND ANIMALS 
209 
retained; the other essential fact is that an approximately 
equal quantity of carbon-dioxide is sent out from the body 
through the breathing organs. Whether we are discussing 
plants or animals, the facts are the same. Thus, all organ- 
isms breathe. The ocean of air, therefore, is an essential 
factor in the environment of every living thing. 
Now, many plants exhibit a special relation to air. These 
are the green plants. Green plants contain in their leaves and 
other young surface parts a granular substance called chloro- 
phyll, which is from the Greek for “leaf-color.” Through the 
agency of chlorophyll the leaf, or other green organ, has the 
power of combining carbon-dioxide drawn from the air with 
water from the soil, and producing a carbohydrate (starch 
or sugar), a simple form of food. In this process of food build- 
ing, characteristic of no organisms but green plants, there is 
an excess of oxygen. This oxygen is sent out into the air. 
Oxygen is thus kept abundant in the air, providing for re- 
newed quantities for breathing. 
The noting of green plants as a group suggests plants that 
are not green. There are such plants and they are sometimes 
called non-green plants or fungi (sing, fungus). Examples of 
non-green plants are mushrooms, molds, yeast, and bacteria. 
None of these have chlorophyll, and hence have no capacity 
to create food. On the contrary', they break down the food 
compounds which they use, causing such disintegrations of 
food as are characteristic of animals. 
The non-green plants are dependent for the food they use 
on living plants or animals, or on the dead food produced by 
plants or directly traceable to animals. If the non-green 
plants obtain their food by consuming juices from other 
plants or from animals, they are called parasites (Lat. 
parasitus, a person who obtains his living by the work of 
another). Examples are all the disease bacteria and many 
plant diseases such as wheat rust, leaf blights, etc. If the non- 
green plants live in the decayed or dead tissue of plants or ani- 210 
ENVIRONMENT OE PLANTS AND ANIMALS 
mals they are called saprophytes (Greek, for “rotten plant”). 
Examples of this type are the mushrooms, that exist on the 
partially decayed vegetation in the soil, or molds, or yeast. 
It is important to note that the green plants reach out to 
the air, the water and the soil, and construct living material 
from what is not alive. On the other hand, animals and the 
non-green plants, whether they subsist upon the tissue of 
animals or of plants, tend to consume, break down chem- 
ically, and to disintegrate the organic substances built up by 
green plants. One group of bacteria plays a very important 
role in entering and causing the decay and disintegration of 
all plants and animals at death. When disintegration is 
complete, the gases, the water and the minerals in solution 
are on their way to being restored to inorganic nature. 
Through this great cycle the elements are in constant process 
of change, and a certain balance in nature is maintained. 
Thus, the interrelations of organisms, although seemingly 
vague and lost in a maze of countless incidents exhibit de- 
pendence that is undeniable. If we realize that green plants 
are the only organisms that have the power to create organic 
food from inorganic materials, the carbon-dioxide of the air, 
the water and the soluble minerals in the soil, we then 
see that green plants must have been the pioneers in organic 
existence upon the earth. As such they doubtless started as 
small and inconspicuous things, and through the process of 
evolution became different from one another, and at the same 
time increased in complication of structure. 
Once we begin to seek examples of dependencies in nature 
we find them in multitudes, and they to assume im- 
portance in the scheme of nature. One of the most obvious 
examples is that of the relations between insects and flowers. 
On p. 41 the activities of the honey-bee are described, and 
on p. 55, those of the butterflies. A great variety of insects 
visit flowers for the purpose of securing food in the form of 
nectar, a sweet sap formed by flowers. ENVIRONMENT OF PLANTS AND ANIMALS 
211 
In the process of evolution both insects and flowers have 
become adapted to one another in form and structure. In 
some species this mutual adaptation has extended to the 
point where flowers, as among certain orchids, cannot “set 
seed” unless the flowers are visited by a certain species of 
insect. 
The parts of a typical flower are shown in Fig. 101. The 
two essential organs are called the stamens and the pistil. 
(Courtesy of the American Museum of Natural History.) 
Fig. 101. Diagram of a Flower. 
The anther of the stamen contains a yellow or orange powder 
called 'pollen. When this pollen falls upon the stigma or top 
of the pistil it completes a process called pollination, and 
starts the process of fertilization or seed production. 
There are two common ways in which pollen is carried 
from stamens which produce it to pistils (on other flowers of 
the same species) which receive it. The wind carries the 
pollen in many species. Insects carry the pollen in many 
more. Wind-pollinated flowers are open, inconspicuously 212 
ENVIRONMENT OF PLANTS AND ANIMALS 
colored, and without odor. Insect-pollinated flowers are 
sometimes open, but always conspicuously colored, with 
odor, and yielding nectar. Often the form of the tube of the 
flower, or the position of the stamens, are adapted to the 
form or habits of movement of a few species of insects, and 
often to only one species of insect. Orchids are among the 
most highly specialized flowers in form. The insects them- 
selves are similarly modified in form of body, covering of 
body, or length or form of mouth-parts that are used in reach- 
ing the nectar. Thus, the interrelations and dependencies 
existing between insects and the flowers of plants are numer- 
ous and far-reaching. 
One of the most dramatic stories of biological dependencies 
was told first by Darwin, and interestingly retold by Prof. J. 
Arthur Thomson in the “The Outline of Science.” It has 
been aptly called the “cats and clover” story. Darwin tested 
the importance of the visits of insects to the red clover by 
covering a hundred heads of that plant with muslin bags so 
that air and sunlight reached the flowers, but no insects. 
From the hundred covered heads not a single seed was ob- 
tained. But one hundred uncovered red clover heads yielded 
27,000 seeds. The uncovered heads had been visited by 
bumble bees, the tongues of which can reach the nectar at 
the bottom of the slender flower tubes. The backs of these 
insects are covered with a thick growth of bristly hair in 
which pollen grains could be entangled. 
Now, bumble bees live in nests in the ground in the fields 
of clover, where the young grubs of the bees are preyed upon 
by field mice. The more field mice that prey upon the nests 
of bumble bees, the fewer bumble bees come to maturity, 
and, in consequence, the smaller the clover crop. 
In districts where cats are plentiful, as near towns and 
villages, the fewer field mice there will be, and the more 
abundant the supply of bumble bees. Finally, under these 
conditions there will be a better crop of clover. ENVIRONMENT OF PLANTS AND ANIMALS 
213 
The more clover there is, the more food there will be for 
cattle, and, indeed, the richer the soil will be, for clover im- 
proves the soil by carrying with it certain soil bacteria which 
combine nitrogen with other elements creating nitrates in 
the soil. Darwin also called attention to the probability that 
with a large number of kindly old ladies in a village there 
Fig. 102. Pollination of Flowers by Insects. 
A, B, Self-pollination possible; C, D, self-pollination impossible, ex- 
cept by the agency of insects; E, F, G, II, self-pollination impossi- 
ble because stamens and stigma ripen at different times; insects re- 
ceive pollen from ripe stamens and visit flower with stigma ready to 
receive pollen. (Courtesy of American Museum of Natural History.) 
would be a correspondingly large number of cats. This again 
would favor the clover. 
It is obvious that the environment of plants and animals, 
though serene and vague in appearance, is full of intense 
activity and meaning. CHAPTER XVIII 
GREEN PLANTS 
Pleurococcus. There ought to be a good common name 
for the plant which makes up the green patches on the shaded 
surfaces of trees, fences and rocks. The common name is 
green slime. It is not a good name, for these green plants are 
not slimy. The presence of green slime on the north side of 
trees, which is usually the shaded or less illuminated surface, 
has given rise to the suggestion that probably the Indians 
used this fact in stormy weather to 
find their way. They might have 
done so. Although the Pleurococcus 
as a green plant requires light, it 
apparently prefers less than the full 
light and heat of the sun. It may 
also find useful the larger amount of 
moisture probably present on the 
shaded surfaces. 
Pleurococcus vulgaris is a one-cell 
plant of microscopic size. But as 
shown in Pig. 103 the single cell 
may be associated with another cell, 
and sometimes with three or more 
additional cells. This grouping of 
cells results from the multiplication of cells by the process of 
fission or division and a subsequent clinging together, thus 
giving the appearance of a many-cell plant. 
The same parts of a cell are found in Pleurococcus as in the 
Amoeba or Paramoecium (Chapter II). There are the cell 
wall, the cytoplasm and the nucleus. In addition, there is the 
Fig. 103. Pleurococcus. 
(From Gager: Fundamentals 
of Botany; P. Blakiston's 
Son & Co., Philadelphia.) 
214 SPIROGYRA 
215 
material which especially characterizes green plants, the 
chlorophyll. In Pleurococcus the chlorophyll is present as a 
single body which nearly fills the whole cell. 
Pleurococcus is an interesting type of the simplest possible 
form of a living thing. It is just as much a plant as an oak 
tree is, for it lives as a complete being. It absorbs water in- 
cluding minerals in solution and carbon-dioxide. It makes its 
own food, digests it, uses it for energy and for the making of 
protoplasm, and it disposes of its own waste. 
When one of these one-cell plants grows to its full size, it 
begins to divide into two, half of each organ of the cell passing 
into each smaller cell. Immediately each small cell begins to 
grow. When the full size characteristic of the cell is attained, 
division takes place again. Thus, the process of reproduction 
by division is in reality connected with the process of growth. 
When a one-cell organism reaches its full size after taking in 
food material for growth, its surface is not capable of taking 
in enough material to supply the need of a larger volume of 
protoplasm. Reproduction in the plant then results in the 
creation of two cells each of which is taking in all the food 
material needed, and growing on it. Reproduction also pro- 
vides for the continuance of the kind or species. 
Spirogyra. Another green plant not so common as Pleu- 
rococcus is Spirogyra (from the Greek, meaning “spiral 
rings”). In the warm months of the year it is found in pools 
of fresh water fed by springs. It appears as slimy mats of light 
green threads a few inches below the surface, clinging to 
submerged twigs and the roots or branches of grasses. Some- 
times, especially on sunny days, the whole mat is apparently 
lifted to the surface of the water by great bubbles of gas. 
We have reason to believe that these bubbles are the oxygen 
which the spirogyra gives off as waste incident to the process 
of the rapid manufacture of carbohydrate (starch and sugar) 
from carbon-dioxide and water. The strong sunlight increases 216 
GREEN PLANTS 
the activity of this process of photosynthesis (Greek for 
putting together by light). 
A few threads of Spirogyra may be placed in a drop of 
water on a glass slide, covered with a thin piece of glass and 
Fig. 104. Spirogyra. 
Above, several filaments, low magnification; 
below, much enlarged study of filaments. Ad- 
jacent filaments in conjugation. (Courtesy 
of American Museum of Natural History.) 
prepared for examination. The compound microscope shows 
clear-walled threads composed of a series of cylindrical cells 
attached end to end. Each cell contains within it symmetri- 
cally arranged spiral bands of green extending the length of 
the cells. There are one, two or more of these spiral bands of SPIROGYRA 
217 
chlorophyll in each cell, depending on the species. Here and 
there in the chlorophyll bands are starch-forming bodies, 
called pyrenoids. 
At the center of each cell is a nucleus with radiating strands 
of cytoplasm extending to the cell walls. The space within 
the cells not occupied by chlorophyll bands, nucleus and 
cytoplasm is a clear area containing cell sap. This cell sap is 
composed of water, sugar in solution, mineral substances 
brought in with the water and probably some wastes. 
Like Pleurococcus, Spirogyra absorbs carbon-dioxide and 
water. Both these materials are abundant and easily secured 
by this plant. The carbon-dioxide, always present in air, is 
available to Spirogyra through the air which is mixed with 
the water. But a great deal of carbon-dioxide is being formed 
all the time in the decay of plant and animal substance in 
pond water. The chlorophyll in the presence of sunlight 
combines the carbon-dioxide and water into a carbohydrate, 
probably first as sugar. Later the sugar is changed to starch 
by the pyrenoids. The oxygen which comes off as a waste is 
left over from the process of photosynthesis as in Pleuro- 
coccus. 
The plant continues its process of food manufacture, 
creating oils and finally protein. Out of protein the plant 
creates its own protoplasm. Protoplasm added to protoplasm 
results in growth. 
When the cells attain their full size they divide by form- 
ing a wall across the middle of the cylinder. The nucleus, the 
chlorophyll bands and cytoplasm divide, and half goes into 
either cell. The growth of the cell is in length only, which 
thus increases the length of the thread. The thread separates 
into parts of variable length, and each part constitutes a 
colony. Sometimes a single cell separates from all others, and 
then is the entire plant, since it is able to carry on all the 
processes of living by itself. 
Spirogyra is an important plant type on account of the 218 
GREEN PLANTS 
fact that it demonstrates the beginning of the sexual process 
of reproduction. For a long time after Spirogyra became 
known to botanists there seemed to be no difference between 
the two threads of the plant as they were observed to take 
part in this process of reproduction. But now it is known 
that there are enough differences to justify designating one 
the receiving or female plant, and the other the supplying or 
male plant. 
In the process of conjugation the two threads adjacent to 
one another begin to form at opposite points extensions in 
the cell walls. They extend toward one another until they 
touch, and a passageway forms. This is called the conjuga- 
tion-tube. The contents of the opposite cells begin to con- 
dense and round up. The contents of the male or supplying 
cells then flow through the conjugation-tube and unite with 
the contents of the female or receiving cells. The united cell 
contents thus form a single body with fused cytoplasm and 
nucleus. The chlorophyll bands of the male cell disappear, 
and on further development the chlorophyll band of the 
female cell becomes the chlorophyll of the new plant. This 
new plant exists for some time in a resting stage. When 
formed it sinks to the bottom and remains there perhaps 
from Autumn till Spring, when it germinates by bursting the 
inclosing wall. The fused cell contents elongate, reproduce 
by division repeatedly until a new thread is formed. 
The Rockweed. A plant very well named because of its 
well-nigh sole possession of sea-worn rock promontories 
between high and low tides is the brown rockweed (see Fig. 10) 
of the North Atlantic Coast, for example. The scientific 
name of a well-known species is Fucus vesiculosus. 
Rockweeds maintain their hold on the rocks by producing 
from the base of the flattened stem a series of short clinging 
branches that inclose a large pebble or insert themselves into 
crevices in the rock mass. These root-like organs are called THE ROCKWEED 
219 
“hold-fasts.” They are not true roots. But they are strong 
enough to keep the little plant in position as long as the rock 
holds. 
Rockweeds are less than one foot in length. One cannot 
speak of the height of this plant, since it is not able to stand 
alone. There are few wood-fibers in the tissue, and nothing 
to hold it up. Hence, as the waves dash against the rocks 
the flat branches are swept up the rocks, and as the waves 
Fig. 105. Conceptacle of Rockweed. 
Several egg-cases borne on stalks containing eight egg-cells. 
(From Kerner & Oliver: The Natural History of Plants; Henry 
Holt and Company.) 
fall back the rockweeds sag in masses to their length and lie 
prone upon the rocks. Numerous bladder-like vesicles or 
cavities in the branches help support the plants in the water. 
The branches of the rockweed are swollen at the tips into 
numerous pit-like organs. These cavities become flask- 
shaped beneath the surface and contain the reproductive 
organs. In some species of rockweed the male and female 
reproductive cells are produced in the same cavity or con- 
ceptucle, while in other species the male and female cells are 220 
GREEN PLANTS 
formed in conceptacles of different plants, or even on differ- 
ent branches of the same plants. 
The advance in the specialization of the reproductive cells 
in the rockweed over the same cells in Spirogyra is consider- 
able. In the rockweed the microscopic female reproductive 
cells or egg-cells are contained in a case borne on a short 
Fig. 106. Egg-Cell and Sperm-Cells of Rock- 
weed. (From Kerner & Oliver: The Natural 
History of Plants; Henry Holt and Company.) 
stalk. There are eight of these egg-cells. When they are 
mature they burst from the egg-case, and escape from the 
opening of the conceptacle and float, about in the water. 
The male or sperm-cells are formed in cases on branched 
stalks from the wall of the conceptacles. When the sperm- 
cells are mature they escape from the conceptacles to the 
water. The sperms are extremely small in comparison with 
the eggs. By virtue of two thread-like lashes the sperms THE ROCKWEED 
221 
under the influence of the chemical attraction of the eggs 
for the sperms make their way to the eggs, and swim about 
them in large numbers. At length one of the sperm cells 
penetrates the wall of the egg-cell. The sperm migrates 
through the egg cytoplasm until it comes into contact with 
the egg-nucleus, when fusion or the union of the two is com- 
pleted. This is called the process of fertilization, a general 
process in all but the lowest plants and animals. The fer- 
tilized eggs of the rockweed when they reach favorable places 
start to grow at once and develop into young rockweeds. 
Although the rockweed is brown, the color only masks 
the chlorophyll which is abundant throughout the plant. 
Through the activity of the chlorophyll in the presence of 
sunlight rockweed carries on photosynthesis just as do fresh- 
water green plants. CHAPTER XIX 
NON-GREEN PLANTS 
Bacteria. Everyone knows about bacteria under the 
name of “germs.” But germs is not a good name, since it is 
also applied to an essential organ in seeds. 
A jar of rotting hay, such as was described in Chapter II 
in connection with the life-history of the Slipper-Animalcule, 
shows countless millions of extremely minute clear, rod- 
shaped particles, occurring singly or in chains. These are the 
bacteria that cause decay. A tiny drop of water from this 
source placed on a glass slide and covered with a thin bit 
of cover glass, if examined under the high power of the 
compound microscope, will be found to contain swarms of 
bacteria. No one ever saw a Bacterium except with the aid of 
such a microscope. They are the smallest organisms known. 
Each of the minute bodies is a cell, a complete organism. 
They move in a rambling, quivering fashion by means of 
numerous thread-like extensions of the cell protoplasm. The 
vibrating threads serve to give the bacteria very slight in- 
dependence, however, since they are carried by currents in 
liquids, by air to some extent, and are attracted or repelled by 
chemical or physical conditions in their environment. 
All bacteria are without chlorophyll. This makes it im- 
possible for them to manufacture their food. Thus, they 
occupy the same chemical position in nature that animals do. 
They break up food compounds; they do not build. The food 
compounds existing in bacteria are only transferred from 
living or dead organisms. 
As stated in Chapter XVII, the non-green plants are 
either parasites or saprophytes. The difference is easily 
222 BACTERIA 
223 
noted in bacteria. Bacteria that live in the bodies of living 
plants or animals are parasites. Examples are the disease 
bacteria of typhoid fever, tuberculosis, etc. Bacteria that 
live upon dead organic matter are saprophytes. Examples 
are the bacteria that live in dead or decaying organic matter 
of all kinds, vegetables, meat, fruits, etc. 
Bacteria are unable to take in particles of food. Beside 
A, Pneumonia; B, Diphtheria; C, Typhoid Fever; D, Blood- 
poisoning. (Courtesy of American Museum of Natural History.) 
Fig. 107. Types of Disease Bacteria. 
the difficulty of finding space within their bodies for even 
the smallest observable particles, bacteria have no mouths. 
Furthermore, the cell wall is not flexible or permeable to 
foreign particles, as is the case with Amoeba (Chapter II). 
Therefore, bacteria must dissolve their food outside their 
own bodies. This is done by the secretion of a chemical 
compound with a digestive function. It is one of a class of 
similar compounds found in all organisms that are called 224 
NON-GREEN PLANTS 
enzymes. Under the action of an enzyme the solid organic 
matter in a mixture in the presence of water gradually be- 
comes liquified. The bacteria absorb the digested product, 
transform it into protoplasm of its own, or oxidize it to pro- 
duce energy for growth, for activity, or for reproduction. 
Reproduction in bacteria consists in the crosswise division 
of the cell. Some kinds of bacteria have been observed divid- 
ing about every half-hour. At that rate, it has been esti- 
mated that if nothing interferes one cell would give rise in 
ten hours to 1,048,576 cells. In twenty-four hours the num- 
ber of bacteria produced would be well-nigh incalculably 
great. Thus the fact that bacteria fill all the nooks and 
crannies of nature is accounted for. The reasons that bac- 
teria are prevented from overrunning and exterminating 
everything else are numerous. No living thing can exist with- 
out food. The moment bacteria, or in fact any organism, be- 
comes so abundant that its customary food is relatively 
scarce, a natural cheek is applied to the increase in numbers 
of the species. There are other factors that tend to hinder 
the increase of bacteria. Heat, cold, dryness, and the prev- 
alence of microscopic animal enemies make terrific inroads 
on their number. In the bodies of the living bacterial hosts, 
which means possibly all organisms above the one-cell forms, 
there are chemical and tissue conditions that hinder still 
more the rapid increase in the number of bacteria. 
Sometimes the other forces in nature threaten to become 
too strong for aggregations of bacteria. Then it is that these 
tiny beings have recourse to a capacity to cease all functional 
activity for a short or a long time. In many species, when it 
threatens to become too dry for them, for example, the con- 
tents of the cells condense and becomes inclosed in a new, 
thicker cell wall. This resting stage is called a spore. In 
this condition it may lie attached to other matter, such 
as dried grass, until the grass may be subjected to immer- 
sion in water as in the hay culture described in Chapter II. BACTERIA 
225 
Thereupon, the bacteria will absorb the thick spore cases 
and resume business in the accustomed fashion. Possibly 
the only condition in which bacteria are carried far in the 
air is in this dry resting stage. Most of the species or kinds 
of disease bacteria, however, do not form spores, a fact 
which we may well appreciate in view of the very great 
difficulty we have already in fighting the ravages of com- 
municable diseases. 
On account of the fact that the word bacteria, or its com- 
mon equivalent “germs,” is known best in connection with 
diseases, these organisms have a bad name. But by far the 
greater number of species of bacteria are useful directly or 
indirectly to man, and in fact to all organic nature. The 
knowledge existing to-day about bacteria has brought about 
immense changes not only in the science of medicine, but 
also in such industries as relate to the production and care of 
food, in maintaining the fertility of soil, and in disposing of 
the wastes of municipalities, and of getting rid of all dead 
organic matter. The understanding of all that may happen 
through the agency of bacteria would be equivalent to having 
a pretty good grip on the comprehension of nature itself. 
Something is said of the bacteria of certain diseases in Chap- 
ters XXXIX and XL. Those bacteria which cause decay in 
dead organisms are useful to all nature in causing the chem- 
ical break-up and the consequent return to earth, water and air 
of elements and compounds that have served their purposes 
in bodies the lives of which have closed. Our imagination can 
picture the condition of the surface of the earth if organisms 
that die fail to decay. It can also enable us to realize the 
fact that the elements and compounds in the earth, water and 
the air that pass into and become part of living things must 
be replenished. There is no other source of supply than the 
organisms which have taken them awray. 
Naturally, many of the bacteria that cause decay or putre- 
faction are found in the soil. But associated with them are 226 
XOX-GREEX PLAXTS 
other soil bacteria which have the opposite effect on sur- 
rounding substances. While the decaying bacteria tear down 
essential chemical compounds, another type, called nitrifying 
bacteria, change some of the products of decay called am- 
monia compounds into nitrates by causing the combination of 
ammonia and nitrogen. On the addition of more oxygen the 
nitrites become nitrates, which may be absorbed by the roots 
of plants. Nitrogen, as we 
know, makes up four-fifths 
of the air, the remainder 
being mostly oxygen. Since 
air permeates the soil, nitro- 
gen is there too. Free ni- 
trogen cannot be used by 
plants. The significance in 
agriculture and in nature 
generally of the presence of 
nitrifying bacteria in the 
soil is apparent when we 
realize that nitrogen is an 
essential element in proto- 
plasm. 
Certain of the nitrifying 
bacteria have been discov- 
ered in small knots or swell- 
ings on the roots of clover, 
peas, beans, alfalfa and re- 
lated plants. These bacteria 
are not parasitic on these larger plants, but are rather part- 
ners in a very important business. In poor soil the clover or 
alfalfa without the cooperation of the bacteria would make 
rather small growth, but with the bacteria, which are some- 
times introduced in cultures, or even occur naturally in most 
places, the growth is very great. It is known that the nitro- 
gen-fixing bacteria after they have taken up and combined the 
Fig. 108. Roots of Clover with 
Tubercles of N itrogen-Fixlvg 
Bacteria. (Courtesy of Brooklyn 
Botanical Garden.) YEAST 
227 
nitrogen, die in great numbers and give up the nitrates to the 
host plant which combines them in its own tissues. When t he 
stubble of the crop is plowed under the soil is thereby en- 
riched. Even before the life-history of these nitrogen-fixing 
bacteria was known, farmers had long alternated clover 
crops with other crops in order to restore soils to their normal 
fertility. 
In Chapter XXVI are recorded other important facts 
about useful bacteria, such as those in milk. 
Yeast. Yeast plants are larger than bacteria and a little 
more highly organized. They are composed of one cell to 
Fig. 109. Group of Yeast Plants. 
At left, active budding cells; at right, cell contents 
changed to spores. (Drawn by Maud II. Purdy.) 
which may be found attached one or more still smaller cells 
in the process of being separated from the parent cell. The 
cells are egg-shaped, surrounded by a wall. The nucleus is 
clearly seen in specimens that are prepared by killing and 
staining. In active specimens a large clear vacuole is visible. 
This vacuole contains water and various substances, possibly 
wastes in solution. 
Yeast plants have in several respects the same life-history 
that bacteria have. This is due to the fact that chlorophyll 
is lacking. There is no mouth or place where food may enter, 228 
NON-GREEN PLANTS 
except by passing into the cell in solution. Enzymes digest 
external food and prepare it for absorption. 
The most characteristic activity of yeast is the process of 
fermentation. This may be observed by stirring a piece of 
yeast cake (cooked potato and yeast) in a mixture of molasses 
and water. In a short time bubbles begin to rise. These have 
been found to be composed of carbon-dioxide. One of the 
enzymes produced by the cells acts on glucose sugar, dividing 
it up into carbon-dioxide and alcohol. Yeast keeps on grow- 
ing in molasses for a considerable time. It causes fermenta- 
tion, and at the same time absorbs some of the sugar which it 
uses as a source of energy by oxidation. The molasses con- 
tains also some minerals in solution and some protein. On 
these the yeast thrives and increases the number of individual 
plants. 
To the plant itself fermentation is probably useful as a 
source of energy for growth and reproduction. In the place 
of oxygen, which ordinarily makes possible a supply of energy 
through oxidation, fermentation appears to give this energy. 
Man has employed fermentation in the making of brew and 
in producing fermented beverages for thousands of years. 
In the making of bread, yeast obtained usually from the 
prepared yeast cakes is mixed with dough. The yeast pro- 
duces an enzyme which transforms starch in the dough to 
sugar. Sugar is then split up chemically into carbon-dioxide 
and alcohol. The yeast uses some of the sugar to develop 
energy, but it feeds on the protein in the bread. 
The carbon-dioxide in rising to escape carries along the 
sticky, glutinous dough, creating spaces in large numbers 
here and there. When the bread is placed in the oven the 
heat still further expands the gas and enlarges the cavities. 
At length the carbon-dioxide and the alcohol as well are 
driven off by the heat. 
All fermented beverages are produced by particular species 
of yeast plants growing in the mixtures from which the bever- BREAD MOLD 
229 
age is obtained. The yeasts that produce the varieties of 
wines are called “wild ” yeasts because they live on the soil of 
vineyards and blow in the dust to the skins of the grapes. 
Cider is fermented into vinegar by a wild yeast that grows 
on the soil under apple trees. 
Yeasts are reproduced by a type of division. But instead 
of equal division, a bud forms at one end of a full-grown cell. 
The nucleus divides equally. The bud formation may go on 
At left, old plant; at right, young plant developed from a 
branch of old. (Drawn by Maud H. Purdy.) 
Fig. 110. Bread Mold. 
until there are several cells clinging together in various stages 
of development. 
Under conditions of extreme dryness or other unfavorable 
circumstances, the contents of a cell will divide into four cells 
with thick walls around each. This is the resting stage com- 
parable to the resting stage of bacteria. As in bacteria it is a 
protection against extermination. 
Pasteur’s great scientific work was on bacteria and yeasts. 
Accounts are given of this work in Chapter XXXIX. 
Bread Mold. Bacteria, yeasts and molds and other non- 
green plants are often classed together as Fungi. They are 
also often found living together where food is stored at 230 
NON-GREEN PLANTS 
ordinary temperatures. Uncover a jar of jelly that has not 
been sealed well, or examine the bottom of a barrel of apples 
that has not been well culled, and you will observe masses of 
green and gray molds and a slimy substance resulting from 
the action of bacteria. There will also be noticeable the sour 
odor that comes from the action of yeasts. 
When bread is left in a moist place for several days a 
special type of mold begins to appear on the surface. This is 
likely to be the species known as Rhizopus nigricans. As the 
mold spreads by lateral branches over the loaf, vertical 
stalks appear over the root-like structures that extend into 
the bread. On the tops of these vertical stalks, actually very 
short, appear minute black specks. These black specks are 
the cases which contain the hundreds of one-cell spores, the 
non-sexual reproductive bodies. Y\ hen the spores are ripe, 
the spore-cases burst and the spores are scattered, and begin 
new plants on the same piece of bread, or lie in the container 
ready to begin active growth when favorable conditions exist. 
Sexual reproduction in this mold is similar to that of the 
Spirogyra. Adjacent branches of separate plants extend 
short branches toward one another. When the short branches 
touch, cells are cut off the tips of either branch, and the con- 
tents of both cells unite after the separating walls are dis- 
solved. The cell resulting from the fusion of the two cells is 
called a zygote. It enlarges and becomes surrounded by a 
thick wall. In that condition it may become a resting cell 
for a long time. At length under favorable conditions the 
zygote bursts and a small sprout emerges. This sprout grows 
upward as a stalk, on the top of which is formed a spore-case 
containing many spores. In this way the sexual reproduction 
of the bread mold actually brings about a large increase in 
the number of plants. 
Ordinarily the effect of the growth of molds on foods is 
destructive. Foods that are attacked by molds are in general 
rendered unpalatable, even if the mold is apparently removed. THE WHEAT RUST 
231 
But Rocquefort cheese is ripened in part by an internal 
greenish mold which gives the cheese its characteristic tang 
or flavor. Camembert cheese also is usually covered with 
mold. The combined effect of the mold and the bacteria 
within the cheese give it a flavor appreciated by many. 
The Wheat Rust. A parasitic fungus disease that does a 
great deal of damage to wheat crops is the Wheat Rust. It 
consists of small red patches scattered over the blades of the 
wheat plant. Their presence in large numbers tends to pre- 
vent the plants from reaching maturity and producing a 
normal yield. 
The wheat rust is an example of a plant parasite that re- 
quires two “hosts” to complete its life cycle. In the early 
spring spores of the parasite infect the leaves of barberry, 
and in the young stems. Thread-like branches of the rust 
grow generally between the cells of the barberry. But short 
branches penetrate the cells and live on the food and proto- 
plasm of the host. Later there are formed on the under sur- 
face of the barberry leaves small “cluster cups” which con- 
tain what are called spring spores. These spores result from 
the division of a zygote by the union of two branch cells in the 
bottom of the cluster cup. 
By this time the wheat plant is large enough to offer space 
for catching the spring spores as they are blown from the 
barberry. The spore germinates on the leaf of the wheat 
plant and sends a fine sprout through a stoma or air-pore of 
the leaf. After this numerous branches are formed and the 
second stage of the life-history is entered upon. 
In a little while the fungus has established itself in the 
wheat plant. It then begins to grow to the surface where 
summer spores are formed. These spores are spread to other 
plants and before long an entire field of wheat may be in- 
fected. Toward the end of the growing season winter spores 
are formed in the same clusters that have formed summer 232 
NON-GREEN PLANTS 
spores. The winter spores consist each of two cells borne on 
a minute slender stalk. 
The winter spores are inclosed in thick walls capable of 
protecting the minute bits of protoplasm contained in them 
from drying. These spores remain on the ground or on the 
stubble until spring returns. Each cell of the winter spore 
then germinates and produces a little plant of four cells. 
From this plant a special type of spore is produced. It is 
called a sporidium. These sporidia are carried in some way 
to the leaf, stem or flower of a barberry where they are liable 
to germinate, thus making the cycle of their life-history 
complete. 
The barberry is usually a host of this parasite. But wheat 
rust is common even where no barberries have been known to 
exist. Wherever rust has been found it has done great dam- 
age. Eradication of the disease by direct methods has not 
proved successful. The most hopeful method of saving the 
wheat crop in some sections of the country seems to be the 
cultivating of hybrid or crossed varieties of wheat. A rust- 
resistant variety brought from the Mediterranean countries 
is being crossed with varieties in this country to produce a 
variety that is rust proof, and has other desirable qualities. 
Mushrooms. The best known fungus is the mushroom. 
This is because some species of mushrooms are edible, and 
some are poisonous. The poisonous ones are often called 
toadstools. Every summer the newspapers contain stories of 
whole families being poisoned, often fatally, from eating 
poisonous mushrooms. There is no positive way of dis- 
tinguishing an edible variety from a poisonous one. The only 
safe practice to pursue, especially when one is collecting 
mushrooms in the woods, is to take only the varieties abso- 
lutely known to be safe. If one becomes expert he may 
gradually extend his collections to those which other ex- 
perienced persons have found to be good. Anyway, no MUSHROOMS 
233 
matter how palatable some mushrooms arc, none is very 
valuable as a substantial article of food. 
The best known mushroom is the field mushroom, Agaricus 
(Psalliota) campestris. This is edible. It may be collected in 
the open fields. But it is cultivated in dark rich beds of soil 
and decaying organic matter maintained in underground 
“root houses” or in barns. Another edible mushroom that 
grows in the decaying leaf-mold about the bases of trees is 
Fig. 111. Field Mushroom. 
(Photograph by Dr. Wm. A. Murrill.) 
the “ shaggy-mane ” mushroom. The name “inky-cap” 
is also given to this and two allied species. Young puff-balls 
are also edible. 
The visible portion of a mushroom consists of a stalk bear- 
ing an umbrella-shaped cap. Under the cap are a great 
number of radially placed thin plates or “gills.” At the top 
of the narrow spaces between these gills are situated the 
spores or the reproductive cells. These are borne four in a 
group on stalks that emerge from the mass of tangled threads 
or strands of which the whole mushroom is composed. When 
the spores are ripe they fall beyond the lower margins of the 
protecting gills, where they are likely to be caught on cur- 
rents of air and carried to other places where they may 234 
NON-GREEN PLANTS 
germinate. No indication of a sexual method of reproduction 
has been discovered. 
Certain species closely related to the mushrooms grow on 
living trees, as well as on rotting logs. One of these is the 
“bracket fungus.” In its method of extending from the 
Fig. 112. Bracket Fungus. 
(Photograph by Dr. Wm. A. Murrill.) 
trunk of a tree, it resembles a shelf. The flat portion of the 
shelf, however, is beneath. This under surface is covered with 
minute holes in the upper ends of which the spores are pro- 
duced. 
The substance of the bracket fungus is added to in plates 
beneath year by year. The root-like base extends into the 
bark and growing tissue of the tree, and in time will destroy 
the tree. CHAPTER XX 
MOSSES AND FERNS 
A Moss. Mosses are always small plants. Some species 
live in swampy places. Among these is Sphagnum, a moss 
that is sometimes collected, dried and used as packing mate- 
rial by nursery men and florists. This species extends from 
the temperate zone far to the North in the Arctic region, 
where it serves as food for reindeer. Other mosses live on 
thin gravelly soil in the woods, on rocks and on bark where a 
small quantity of soil has collected. Thus, they are obliged 
to survive periods of considerable dryness. 
Mosses are true green plants. They contain chlorophyll, 
and are able to create their own food, drawing water and 
minerals in solution from the soil, and obtaining carbon- 
dioxide from the air. Many organisms are called moss that 
are not moss at all. Among these incorrectly so called are 
Pleurococcus described in Chapter XVIII and many species 
of the gray-green lichens that grow on rocks and fences. 
Lichens are in reality two plants living in a partnership rela- 
tion, a one-cell alga and a many-cell fungus. 
One of the best known mosses is the hair-cap moss, Poly- 
trichum commune. This species is from two to three inches 
high. This moss, as well as others, exhibits two distinguish- 
able forms. One is the form which in this species gives the 
basis for the name hair-cap, the other is without the fringed 
cap at the top of a slender stalk that extends beyond the 
leaves, and shows instead a shallow, flaring top at the end 
of the slender cluster of leaves. The hair-cap form bears at 
the top a capsule containing many spores. This is called the 
female plant for a reason that will appear presently. The 
235 236 
MOSSES AND FERNS 
other form is the male plant. The top of the male plant 
resembles a tiny flower in shape and appearance. At the 
center are slender spindle-shaped organs called antheridia. 
These antheridia produce antherozoids or sperm-cells. Before 
the female plant produces its stalk and cap it has a top 
similar to that of the male plant. But instead of producing 
antheridia, it has at the center of the “flower” a group of 
flask-shaped organs called arehegonia. In the bottom of each 
archegonium is an egg cell. 
Fig. 113. Life-History of a Moss. 
Male and female plants at left, flowers at top; top middle, section showing 
three arehegonia; bottom middle, section showing three antheridia; adjacent 
at right, archegonium and (below) antheridium with escaping sperm- 
cells; at right, asexual stage. (Courtesy of American Museum of Natural 
History.) 
The arehegonia and the antheridia complete their develop- 
ment at a time when free water is available about them. At 
such a time the sperm-cells escape from the antheridia and 
make their way by means of vibratile or waving lashes to the 
arehegonia. They pass down the neck of an archegonium. A MOSS 
237 
The first sperm to reach the egg-cell begins to fuse or unite 
with it. The remaining sperm-cells die. 
The union of the sperm-cell and the egg-cell is the same 
process of sexual reproduction we discussed in connection 
with Spirogyra, the bread mold, and the rockweed. In the 
moss, however, the two sex cells are more highly specialized. 
One of the archegonia and its contents begin to manifest 
signs of activity. All other archegonia in the same plant die 
whether their egg-cells are fertilized or not. This chief egg- 
cell divides into numerous cells most of which gradually 
transforms into a spore case with spores. A stalk begins to 
form beneath and the top part of the archegonium is torn 
from the branch portion to be carried upward as a cap on top 
the spore case. 
When the spores are ripe they are thrown out. They 
eventually germinate, and if the situation is favorable a veiy 
fine thread of a few cells is formed, called the protonema 
(meaning first thread). From this protonema a small moss 
plant begins to grow. From that time it is merely a con- 
tinuance of development until the two male and female 
plants are produced. Thus, it is that one may begin any- 
where and by tracing the changes in a moss plant come back 
to the same point. In other words, the life-history of moss 
is a cycle, invariably the same for each species. Further- 
more, there is an alternation of generations or a change from a 
sexual generation to a non-sexual or asexual generation, and 
from asexual to sexual. The sexual generation in the moss 
begins with the germination or sprouting of the spore. It 
includes the protonema, the formation of male and female 
plants and the fertilization of the egg-cell in the archegonium, 
and ends with the resulting zygote or fertilized cell. This 
fertilized cell constitutes the beginning of the embryo, as well 
as the beginning of the asexual generation. In the moss the 
asexual generation is relatively short and simple. As already 
described it consists of the dividing of the embryo and its 238 
MOSSES AND FERNS 
development into the spore-case, the spores and the support- 
ing stalk. 
A Fern. Ferns are among the most beautiful of our native 
plants. In the woods they seek the moist, shady spaces, and 
give to pleasure-hunters in nature some of their most gratify- 
ing experiences. Who has not seen a massive cinnamon fern 
with its enormous spreading fronds or leaves surrounding 
several sturdy shafts of brown spore-bearing stalks? Then 
there are the masses of 
rock-ferns. Polypodium, 
skirting the margins of a 
cliff, or the dainty maiden- 
hair ferns clinging to the 
moss-covered dripping 
sides of a shaded crag. 
Some of these species and 
others are capable of be- 
ing adapted to house con- 
finement and cultivation. 
Some like the Boston fern, 
Nephrolepis, grow well, 
but occupy a great deal 
of space. The maiden- 
hair is often used for dinner table decoration, but is difficult 
to rear. 
The botanist has a double satisfaction in his knowledge of 
ferns. If he is artistic he will appreciate their beauty. If 
he is scientific he will appreciate the clear manifestation of 
life phenomena in the wonderful series of changes in form in 
the life history of ferns. 
Many species of ferns bear on the under surface of the 
fronds black or brown regularly arranged dots smaller than 
a pin head. These are called sori (sing, sorus). The covering 
of the sorus conceals a large number of sporangia or spore- 
Fig. 114. Cinnamon Fern. 
(Courtesy of Brooklyn Botanical Garden.) A FERN 
239 
cases borne on slender stalks. Within the sporangia are 
numerous spores. Estimates have been made of the number 
of spores a single plant may produce. In one species the esti- 
mate is 50 millions. When the sorus covering breaks the 
sporangia pop open, and throw the spores considerable dis- 
tances from the parent plant. The spores do not all germi- 
nate, of course, on account of the lack of space for so great a 
Fig. 115. Archegonia of a Fern. 
A, young archegonium; B, mature stage; C, top view and canal. 
(From Gager; Fundamentals of Botany; P. Blakiston’s Son and 
Co., Philadelphia.) 
number of plants adjacent to the parent plants, and also on 
account of some spores falling in unfavorable localities. 
The first result of the bursting of a spore wall is the exten- 
sion of a minute rhizoid or root-like organ to the soil. Then a 
few cells form the protonema or first thread, comparable to 
the protonema in mosses. But the fern protonema adds more 
cells and grows into a delicate flat, plant, a fraction of an inch 
across, usually with a heart-shaped outline. These heart- 
shaped plants lie flat against the ground, but are seldom seen 
in nature. They may be seen, however, in a greenhouse 240 
MOSSES AND FERNS 
where they attach themselves by a small tuft of roots to 
flower pots and to moist frames. Thus, with the flat green 
heart-shaped leaf exposed to the light and the rootlets grow- 
ing into a few tiny particles of soil, this small plant is able 
to maintain itself while it performs its important function. 
This stage of the fern is called the prothallus (meaning, 
first plant). The prothallus is a sexual organism, for on the 
Fig. 116. Fern Prothallus. 
Above, cross-section showing antheridia and 
archegonia; below, enlarged antheridium and 
(sp) sperm-cell; rh, rhizoids,root-like organs. 
(From Gager: Fundamentals of Botany; 
P. Blakiston’s Son & Co., Philadelphia.) 
under surface near the middle there is a set of archegonia 
containing egg-cells, and near by among the rhizoids (mean- 
ing, root-like organs) there are several antheridia, containing, 
antherozoids or sperm-cells. 
When the prothallus has reached its complete develop- 
ment, it is ready for rainy weather. In the presence of free A FERN 
241 
water the terminal cells of the arehegonia and the antheridia 
swell and break. The neck-canal of the archegonium is thus 
open to the entrance of sperms that have been swimming 
through the water to the opening of the neck-canal. 
Many sperms enter from the same prothallus or from 
others. But the first sperm to reach the egg-cell in the bot- 
tom of the archegonium unites with it, and thus accomplishes 
the process of fertilization. This completes the sexual genera- 
Fig. 117. Development of Asexual Generation of Fern from Pro- 
thallus. 1, prothallus without asexual generation; 2, 3, 4, 5, 
prothalli with asexual generation developing. (From Gager: Funda- 
mentals of Botany; P. Blakiston’s Son and Co., Philadelphia.) 
tion which began with the germination of the spore. The 
asexual generation begins with the fertilized egg. This is 
called the zygote or sometimes the oosperm, which name 
indicates a structure composed of the egg and sperm. It is 
also the embryo. The embryo now begins to divide in the 
bottom of the archegonium that has got the start of the 
other archegonia on the prothallus. After many cells in the 
embryo have formed by the process of dividing, the cells 
begin to group themselves into a root, a stem, a leaf and a 242 
MOSSES AND FERNS 
“foot.” The foot is the organ which establishes a connection 
between the embryo and the prothallus. The importance of 
this root is that it enables the young embryo to draw food 
from the prothallus until such time as the new7 root system, 
the stem and the leaves of the asexual generation can begin 
to create its own food, and take care of itself. 
The asexual generation begins with the fertilized egg and 
ends with the spore that has been produced under the frond. 
In the era of the world’s history, many million years ago 
when the vegetation lived that subsequently formed the 
great mass of our coal, ferns were the highest type of plant in 
existence. There w7ere many species, some of them growing 
as large trees. CHAPTER XXI 
THE INDIAN CORN 
The Indian corn plant is the first in importance among 
food plants in the United States. The census of 1900 showed 
that one-third of all the land under cultivation in the United 
States was planted to corn. We produce over three billion 
bushels of corn annually. But relatively few people in the 
great cities seem to eat corn bread. However, in country 
districts and especially in the South corn bread is popular. 
By far the largest quantity of corn is used to fatten pigs and 
cattle. In fact, there have been times, especially in years of a 
heavy yield of corn when it did not pay the farmers to sell 
corn at the low prices prevailing. Corn raising was profitable 
then when the food thus created could be transformed into 
pork or beef. At any price for corn it is more advantageous 
thus to transform the corn food into animal food. 
Although three-quarters of the total quantity of corn pro- 
duced in the world each year is produced in the United States, 
the grain is grown in all the temperate regions on all con- 
tinents both north and south of the Equator. The early 
explorers found the American Indians raising some of the 
same varieties of Indian corn known to-day. Like the 
tobacco plant, which is a native plant in America, Indian 
corn was early exported to Europe for experimental growth. 
The ancestral species of all varieties of Indian corn is 
thought to have existed in Mexico, since the closest known 
relative of Indian corn grows there now. Indian corn is 
supposed to have developed from this relative, possibly 
thousands of years ago. 
Under the care and intelligent selection of varieties by 
243 244 
THE INDIAN CORN 
the white settlers Indian corn increased in importance as 
a food for man. The experienced farmers and the agricul- 
tural experimenters of later years still further improved the 
species, which is known to scientists as Zea mays. We now 
have over five hundred varieties of 
this species classed under the com- 
mon terms, pop corns, flint corns, 
Dent corns, soft corns and sweet 
corns. 
The flint, and the few varieties of 
soft corn are called “field” corn. All 
of these produce corn meal and hom- 
iny, or are used as food for animals. 
Under improved cultivation and the 
proper selection of seed for planting, 
the chief varieties produce fine large 
“ears” of corn with numerous grains 
set in rows. A good ear is shown in 
Fig. 118. 
One, two or three ears of corn grow’ 
on a single stalk. Fig. 119 shows 
one ear with the husk and “silk” 
partly removed. The plants grow 
from seeds planted in rows about 3 
feet 4 inches apart, and separated 
from 12 to 20 inches in the rows. 
The height of corn plants may be as 
great as ten feet, but better yields 
may be expected of shorter plants. 
Throughout the country the yield 
of corn is about 28 bushels of dry, 
shelled grains per acre. But in nearly every section of 
the United States more than 100 bushels per acre have 
been produced. Under especially favorable conditions good 
land has yielded 200 bushels of dry, shelled corn per acre. 
Fig. 118. Eak of Corn 
Showing Cob. (Photo- 
graph, U. S. Dept, of Agri- 
culture.) THE INDIAN CORN 
245 
The best results have been obtained 
by boys who belonged to corn clubs. 
The increase in yield obtained by in- 
tensive cultivation of small plots of 
ground has helped to set high the 
standard of corn production for the 
whole country’. Scientific experi- 
menters working at state and na- 
tional experiment stations have also 
helped to show the general farmer 
how to make his land yield more 
abundantly. 
Certain factors are taken into con- 
sideration always when increased 
yields in corn are being sought. 
Among these factors are, 
1. The selection of the most per- 
fect seed ears. 
2. Preparing the seed for plant- 
ing by sorting for perfect 
grains and for germinating 
capacity. 
3. The selection and preparation 
of fertile,deeply plowed soil. 
4. Liberal supply of soil water and 
well-decomposed manure. 
5. Protection against crows and 
cutworms. 
Scientific farming is gradually be- 
coming general owing to the farmers’ 
bulletins that are issued by the U. S. 
Department of Agriculture. The suc- 
cessors of the old time farmers who 
used to express contempt for the 
Fig. 119. Cornstalk with 
Ears. (U. S. Dept. Ag.) 246 
THE INDIAN CORN 
“college fellows” who gave advice about crops are now send- 
ing their boys to college. And because the colleges arc 
keeping more and more in touch with real farm life, their 
contributions to the success of organized food production 
have been very great. 
ROOTS 
The Indian corn plant is a member of the grass family. 
Although the plant is annual, the stem is strong enough to 
bear the weight of the one to several ears of corn, as well as 
to withstand the pres- 
sure of a strong wind 
against the broad leaves 
and the speading tassel 
at the top. Apparently 
as a preventive against 
the accident of a corn 
plant being uprooted a 
few circles of prop-roots 
or brace-roots grow out 
from low joints of the 
stem, and sink into the 
soil. Very early in the 
development of the root 
system from the seed the 
lowermost joints in the 
young stem give rise 
to numerous finely 
branched roots which 
together with the first 
or primary root consti- 
tute the extensive root system. 
Throughout the five months of life of the plant the root 
system is carrying upward great quantities of soil-water in 
which there is dissolved such soluble minerals as are charac- 
Fig. 120. Root-Hairs. 
At right, root-hairs on corn rootlet, root-cap 
at end; left, single root-hair of wheat 
shown as part of a cell, soil particles 
clinging. (Courtesy of American Museum 
of Natural History.) THE INDIAN CORN 
247 
teristic of the soil. Near the tips of the finest root divisions 
the surface is covered with a fine white velvet-like mat of 
root-hairs. These root-hairs consist of single cells, with very 
thin walls, within which is protoplasm and a cell-nucleus. 
It is only through these root-hairs that soil-water may enter 
the roots at all. 
THE STEM 
The stem of the corn 
olant extends as a single 
italic from the roots to 
:he tassel with only the 
ihort stems of the ears as 
tranches. The stem is 
round except for a flat or 
shallow-grooved vertical 
region above each leaf. 
\s the leaves change posi- 
tion, so these grooved re- 
gions appear first on one 
side of the stem and then 
on another. 
A cross section of a 
stem shows the ar- 
rangement of cells as they 
appear in older stems, 
rhe mass of the interior 
tissue, or groups of similar 
cells, is pith. The surface 
of the well grown stem is 
covered with a tough rind 
which adds greatly to the 
strength of the stem. The 
microscope shows the pith to be made up of numerous thin 
walled, loosely packed cells. Scattered here and there within 
the pith are what are called fibro-vascular bundles. These 
Fig. 121. Cross-Section of Corn Stem. 
Showing external “rind,” thin wall pith 
cells, and dense fibrovaseular bundles. 248 
THE INDIAN CORN 
bundles consist of numerous slender wood and bast fibers and 
a few tubes (vasculce) extending lengthwise of the stem. 
The water and dissolved mineral substances absorbed by 
the root hairs are carried up the roots to the base of the stem. 
There the incoming water or sap passes up the stem and out 
the leaves by way of the wood fibers and such ducts or tubes 
as are included in the wood tissue. 
On the return journey the sap 
comes down the bast fibers and 
tubes. 
The statement has been made 
that the water and minerals in solu- 
tion or the soil-water enters the 
root-hairs and passes up to the 
leaves. We all know this must 
take place, but perhaps it may not 
occur to us to inquire how it is 
done. It is, indeed, remarkable 
that water is carried upward in a 
tall tree apparently with no effort, 
when it would be impossible for 
the most powerful fire engines to 
force water directly to the upper 
stories of our very high buildings. 
The explanation we are seeking 
may be prepared for by studying 
the behavior of solutions. 
If we take a tube, and tie closely 
over the open end a slender sac of 
softened parchment or animal 
membrane like a section of an in- 
testine, oiling the crevices to make the connections water- 
tight, we have an apparatus that will represent a plant cell. 
Into the small end of the tube we pour a dense solution of 
sugar, filling up the sac and a portion of the tube. The 
Fig. 122. Osmosis Experi- 
ment. Showing sac con- 
taining sugar solution; 
water penetrating mem- 
brane rises in tube against 
force of gravity. (Drawn 
by Maud II. Purdy.) THE INDIAN CORN 
249 
tube is then adjusted in a tumbler of water and clamped in 
position. 
In a few hours the solution has risen in the tube, and over 
night it may rise twelve inches or more. To understand this 
you may recall having noticed that a lump of sugar, a pinch 
of salt, or a spoonful of medicine in a glass of water will dis- 
tribute through the water in a short time. This distribution, 
or diffusion, as it is called, keeps up until the whole solution 
is equally dense. The reason diffusion continues until com- 
pleted is that the molecules (smallest particles) of water and 
the molecules of substance being dissolved have a strong 
attraction for one another. 
In our experiment the dense solution of sugar and the 
water of the tumbler containing no sugar are separated by a 
membrane. But observation has shown that water may 
pass through the membrane, although the membrane does 
not leak. If we taste the water of the tumbler we find 
that a little sugar has passed through the membrane, but 
not much. The explanation of this condition is that even 
when separated sugar-water and water will continue to at- 
tract one another and seek to mingle. The water is able to 
pass through the membrane spaces, because the water mole- 
cules are small. The sugar molecules are larger, and have 
difficulty in getting through. Thus comes the high level of 
water in the tube. Let us apply this principle to the cells of 
the plant. 
The cells of plants contain sugar, chiefly glucose. Soil 
water contains no sugar. The membrane of every one of the 
millions of root hairs are permeable (may be penetrated) to 
the soil-water. Thus soil-water comes into the root-hairs, 
but no sugar passes out. In each set of cells with which 
the incoming water comes in contact there is less water than 
can be used in a solution of sugar. And the reason there is 
always less water is because it is being given off constantly 
through the air-pores of the leaves. Thus, from cell to cell, 250 
THE INDIAN CORN 
from root to stem, from stem to branch, and from branch 
to leaf, the procession of countless molecules of water marches 
upward. 
THE LEAVES AND THEIR WORK 
The leaves of the corn plant join the stem at joints singly. 
The leaf clasps about the stem in sheath fashion. Leaves 
are long and slender, and the midrib and veins run parallel 
lengthwise of the stem. The midrib and veins are composed 
of fibrovascular bundles and are directly connected with 
these structures in the stem. 
Photosynthesis.—-—One of the most important functions of 
the leaf is the creation of food. What happens is exactly 
what happens in all green plants. Carbon-dioxide from the 
air and water from the soil are the raw food materials which 
meet in the leaves and are combined in the process of photo- 
synthesis (putting together by light). The thinness of leaves 
permits light to penetrate all their tissues, and to stimulate 
the protoplasm and chlorophyll (leaf-color) to complete the 
steps necessary to carbohydrate formation. Incidental to 
the process of photosynthesis, oxygen is present in excess, 
and thus is considered a waste. 
As already stated on p. 217, the first product of photo- 
synthesis is a form of sugar. Under certain conditions this 
sugar is changed to starch. In daylight the carbohydrate is 
formed rapidly. A leaf cut from a plant toward the close of 
day, and subjected to chemical treatment to remove the 
chlorophyll, will, on the application of a food test, show large 
quantities of starch. But in the night all this starch is acted 
upon by an enzyme (digestive chemical in plants) and changed 
to sugar again. There are twro reasons wrhy the action of the 
enzyme is necessary; first, it is necessary to remove all starch 
to give space for more, secondly, the molecules of starch will 
not pass through a cell wall. The molecules of sugar will. RESPIRATION 
251 
Sugar is the form in which food is carried about the plant 
to serve as material for oxidation, and as the basis for the 
more elaborate protein compound. 
Transpiration. An active plant absorbs through the 
root hairs a great quantity of soil-water. The soluble mineral 
portion of this water is used in part by plants in the formation 
of protein. But it requires a large quantity of water to dis- 
solve a small quantity of mineral compounds. Thus, when 
the minerals in solution are used up by the plant cells, the 
water comes to the leaves free of all dissolved substances. 
Some of it is employed in photosynthesis, but the greater 
portion is no longer needed, and is waste. It passes out 
through the air-pores (stomata, Greek for little mouths) in 
the form of vapor. This process of sending out excess water 
is called transpiration. 
Respiration. Confusion is likely to arise in our minds with 
regard to respiration or breathing in plants. This is because 
of the emphasis naturally placed on the fact that the leaves 
absorb through the air-pores or stomata a large quantity of 
carbon-dioxide for photosynthesis. As a matter of fact, 
plants and animals are forced to breathe for exactly the same 
reason. Both require free oxygen to combine with food thus 
yielding the energy necessary to carry on the work of the 
organism. The chief form of energy characteristic of plants 
is the chemical energy necessary to food formation and 
growth. 
Although the air-pores take in oxygen along with the 
carbon-dioxide, the plant employs in the process of respira- 
tion or breathing some oxygen that is released in the process 
of photosynthesis. In fact, the probability is that wherever 
oxygen occurs free in the plant there it is used to release 
energy by combining with carbon or with hydrogen in its 
own food compounds. We understand respiration to mean 252 
THE INDIAN CORN 
the taking in or securing of oxygen 
and the formation and setting free 
of carbon-dioxide. The beginning 
and end of this process is what is 
especially considered respiration in 
man. Wherever and however the 
same events occur, the process is 
called respiration. 
In July the flowers of the corn 
plant begin to develop. They first 
appear at the top of the plant. These 
are called the st a minute flowers, be- 
cause they contain the pollen-bearing 
stamens only. The cluster is called 
the tassel. A single flower (Fig. 123) 
contains three stamens surrounded 
by a number of dry, husk-like bracts. 
When the tassel is well formed, one 
may discern extending upward from 
the angle between the stem and a 
leaf a small tuft of delicate silk from 
a budding ear of corn. The ear, 
when its form becomes fully appar- 
ent, is made up of a central core 
called a cob, on which are set in 
rows running longitudinally numer- 
ous pistillate flowers. These flowers 
consist of two minute scale-like 
bracts, an ovary containing the germ 
of the seed, and a long, silken style. 
Surrounding the ear are husks which 
consist of enormous bracts extending 
from the base of the ears beyond 
the tips of the ear. 
In the latter part of July, usually, the staminate and the 
Fig. 123. Pistillate and 
Staminate Flowers of 
Indian Corn. Young 
ear showing styles or silk 
extending from pistillate 
flowers to tip of husk; at 
left, pollen dusting on tip 
of stigma. (Drawn by 
Maud 11. Purdy.) RESPIRATION 
253 
pistillate flowers are mature. The pollen of the stamens then 
breaks from its covering, and being light and dust-like, is 
caught up and blown away by the wind. Vast quantities of 
pollen are carried across a corn field, much of it falling on the 
ground between the rows, or beyond the field altogether. 
When pollen falls upon the end of the silken styles of an ear 
of corn, whether from the same plant or from a distant one, 
pollen grain forms a fine tube still more slender than the style. 
This pollen tube grows down the length of the style to the 
ovule in the ovary itself. There the 
tube penetrates an opening in the 
ovule. 
Then from the pollen grain still 
attached to the top or stigma of the 
style there passes down the tube a cell 
called the sperm-nucleus. This cell 
finally comes to rest adjacent to an 
egg-nucleus in the ovule. The sperm- 
nucleus and the egg-nucleus unite to 
form what corresponds to the zygote 
of the lower forms described in Chap- 
ters XIX, XX. The zygote gives 
rise to the embryo. 
The embryo is the essential part of 
the young plant which is contained in 
all seeds. The parts of the embryo in 
the corn grain are the plumule from which may be traced 
stem and the leaves and certain of the roots. From the 
radicle comes the primary root. The remainder of the em- 
bryo is the seed leaf. 
Packed about the embryo, but not inclosing it, is the horny 
and starchy endosperm. The endosperm is the food material 
of the young plant, a fact clearly shown by the gradual 
absorption of that part of the grain when the corn seedling is 
developing. 
Pig. 124. Longitudinal 
Section of Corn 
Grain. En, endo- 
sperm; cot, cotyledon; 
pi, plumule; r, radicle 
or root; em, embryo. 
(Drawn by Maud H. 
Purdy.) 254 
THE INDIAN CORN 
There are four kinds of food substances in the com grain 
available to the germinating plant or to man who makes his 
levy upon nature after having stimulated nature to develop 
the bountiful supply from small beginnings. These four food 
substances are, first, starch, obvious in the chalk-like masses 
in the grain. There is sugar in the endosperm and in the em- 
bryo especially during germination. There is fat or oil mainly 
in the embryo, and protein throughout the grain. 
THE PRODUCTS OF CORN 
Corn Meal. Until near the time of the Civil War it was 
common merely to grind up the grains of corn between the 
old-fashioned mill stones, to bolt or sift the meal by hand, 
and then to prepare it for the “hoe” cake, johnny cake, 
“hasty pudding,” or Boston brown bread. It is now the 
custom to kiln-dry the corn, remove the outer skin and also 
the embryo, leaving only the endosperm. Then the meal is 
bolted or sifted through great cylinders of fine silk cloth. 
Drying the grains and removing the embryo with its con- 
tained oil improves the keeping qualities of the meal. 
Samp and Hominy. Samp and hominy are prepared as 
corn meal is. The outer skin is removed by softening and 
the embryo is taken out. But the endosperm is broken into 
large pieces. In samp the pieces are very large, and in 
hominy the pieces are not larger than a pin head. But in 
some sections of the country the name samp is applied to the 
small pieces and hominy to the large pieces. 
The old-fashioned way to prepare hominy was to soak the 
grains in lye obtained from water and wood ashes. The lye 
softened the grains and loosened the skin of the grain. By 
stirring the grains the skins were removed. And by soaking 
the grains in clean water afterward the lye was removed from 
the grains. The grains were then soft, and after cooking by 
boiling were very palatable. A popular Southern food com- CORN OIL 
255 
biiiation used to be “hog and hominy,” and is still in country 
districts. 
As cereals, samp and hominy require long cooking, but 
when thoroughly cooked are excellent for anyone. 
Corn Starch. A grain of corn broken into a few large pieces 
shows near the center a region of chalk-like whiteness. This 
is nearly pure starch. It can be separated from the re- 
mainder of the grain by certain processes. It is then called 
corn starch. Corn starch is used a great deal for thickening 
sauces, ami as the basis of puddings. 
Glucose. Reference has been made before in this chapter 
to the fact that starch may be changed to sugar in the plant. 
The sugar to which starch is changed is glucose. This change 
may be induced artificially for commercial purposes by boil- 
ing corn starch with hydrochloric acid, and refining and 
evaporating the material produced. 
Glucose products, both liquid and solid, are now used with 
success in making candy. Glucose hardens and crystallizes 
as easily as cane sugar. It is quite possible that another 
fact receives some consideration by candy manufacturers. 
And that is the fact that glucose is less sweet than cane 
sugar is. As every' one knows it is not possible to consume 
as much home-made candy, which is customarily made of 
cane sugar, as one can eat of “store” candy. Besides, glucose 
is cheaper than cane sugar is. 
Corn Oil. We have already noted the fact that the em- 
bryo of the corn grain is removed before the grain is ground 
up for corn meal. However, the embryo is not wasted. It is 
used as a food in fattening live stock, pigs especially. It is also 
used in increasing quantities every year to produce salad oils 
and cooking oil. There are trade names for the products, and 
the oil products give complete satisfaction, besides being less 
expensive than olive oil. They are more digestible than lard. CHAPTER XXII 
THE BEAN 
In the states of New York, Michigan, California, Wiscon- 
sin, Maine and Florida, the growing of beans in field and 
garden has become one of the best paying enterprises a 
farmer or gardener may engage in. In fact, beans have dis- 
placed wheat in some areas, owing to decreasing fertility of 
the soil for wheat, as well as to the better economic return 
from the production of beans. 
Beans are valuable as food, being especially rich in protein 
(Chapter XXVIII). In countries where meat is expensive, 
beans are eaten in great quantities by those who cannot 
afford to buy meat often, and by many who can. In every 
language one may find the word for “bean,” which fact in- 
dicates the wide use of the plant throughout the world. 
Aside from the fact of producing a valuable food in the 
seeds and green pods of the plant, beans belong to a family of 
plants that performs an extraordinarily valuable biological 
service. This service consists of renovating or rejuvenating 
the soil through the activity of nitrogen-fixing or nitrifying 
bacteria. It was related in Chapter XIX how the bacteria 
grow in small knots or tubercles on the roots of beans, peas, 
alfalfa, clover and other members of the pulse or pea family, 
and cause free nitrogen of the air lying between particles of 
soil to combine with free oxygen in the soil. While the field 
and garden beans are not so active in the production of nitro- 
gen compounds as are the important forage plants, such as 
soy beans and cowpeas, nevertheless they do combine nitro- 
gen and oxygen to such an extent that the land is improved. 
This makes the growth of beans a doubly valuable soil product. 
In Chapter XXIX you will find green beans mentioned 
256 THE BEAN 
257 
among the green vegetables that supply iron, an important 
need of our blood. Of late years green beans have been 
available all year round. The Southern states, especially 
Florida, in the w'inter time grow' and ship vast quantities of 
green beans, as well as other fresh green vegetables, to the 
Northern markets. The cost is two and three times what it 
is in the Northern summer time, but the body’s need must 
be supplied. 
THE WHOLE PLANT 
There are two types of bean plants, one that grows as a 
low bush-like annual plant, the other that climbs a slender 
support by twining the stem about it 
Thus, they are called bush beans am 
pole beans. The well-known Lim; 
beans are usually pole beans. Some 
of the common kidney beans are bus! 
beans and some are pole beans. Or 
account of the great richness anc 
palatableness of Lima beans they arc 
grown in large quantities, but othei 
beans grown are mostly bush beans 
on account of the greater ease with 
which bush beans are cultivated anc] 
harvested. 
Like other green plants bean plant- 
create their own food from the water and minerals obtained 
in solution from the soil and from the carbon-dioxide in the 
air. They grow rapidly, and even in soil of ordinary fertility 
will produce edible pods of green beans in six weeks from the 
time of planting. A professional gardener may thus have a 
garden in New Jersey, another in Virginia or in the Carolinas, 
and another in Florida, and he may move from one to an- 
other, keeping busy all the year round. Some gardeners 
actually do this. 
Fig. 125. Bean Seed 
Opened. Interior of 
seed-leaves exposed; 
plumule above, and 
rod-shape radicle. 
(Drawn by Maud H. 
Purdy.) 258 
THE BEAN 
The life history of the bean 
may be said to begin with the 
germination of the seed. This 
takes place in the soil a few 
days after the planting of the 
seeds one and one-half to two 
inches deep. A cluster of roots 
soon forms from the free tip of 
the radicle in the seed. The 
roots give attachment to the 
soil. Covering the surface of 
the roots is the thick mat of 
root hairs. These root-hairs 
as in corn are thin-walled cells 
capable of absorbing water with minerals in solution. 
The remainder of the radicle begins 
to grow longer, thicker and stronger. 
The result is that the thick seed-leaves, 
their covering and the plumule are 
pushed above the surface of the ground. 
In a little while the seed-leaves spread 
and the plumule opens out, grows larger, 
takes on the green color of leaves, and 
becomes established as the first pair of 
permanent leaves of the plant. The 
seed-leaves at first are swollen beyond 
their normal size in the seed by having- 
taken in water, but soon shrinking is 
evident in the wrinkles that appear on 
the surface. Eventually, the seed-leaves 
dry and fall off as withered remnants, 
having given up their rich nourish- 
ment to the young plant. Seeds of all 
the seed-bearing plants contain food 
GEHMINATION 
Fig. 126. Cross-Section of Stem 
of Bean Seedling. Pyramid- 
shaped fibrovascular bundles form- 
ing at cambium layer; pith cells 
at middle; bark outside f. v. bun- 
dles. (Drawn by Maud H. Purdy.) 
Fig. 127. Demonstra- 
tion of Path of Sap 
Circulation. (Cour- 
tesy of American Mu- 
seum of Natural His- 
tory.) THE BEAN 
259 
that the “mother-plant” produced and stored there. Out of 
this food the young plant makes roots, stem and leaves suffi- 
cient in number and size to enable the young plant to take 
care of itself. This pro- 
vision for a new genera- 
tion reminds us of what is 
noticeable in the eggs of 
animals. The germ of the 
animal in the egg is very 
small. The remainder of 
the egg is food for the new 
creature, and is all used 
before the hatching takes 
place. 
THE STEM 
The stem of the bean, 
like the stem of all plants, 
serves the function of 
holding the leaves up to 
the light and air and of 
serving as the pathway 
by which water and min- 
erals are carried up and 
dissolved food is brought 
down from the leaves. In 
the corn plant we discov- 
ered a type of stem struc- 
ture and arrangement ol 
tissue that is character- 
istic of all flowering 
plants that have one leaf 
or cotyledon in their seeds. The corn plant represents 
the monocotyledons (plants with one seed-leaf). The 
bean, as you know, has two seed-leaves. It is, there- 
Fig. 128. Cross-Section Diagram of 
Typical Dicotyledonous Stem. 
1, lenticels (breathing pores); 2, outer 
bark; 3, inner bark; 4, fibrovascular 
bundles; 5, medullary rays; 6, 7, wood 
ducts; 8, wood fibers; 9, sieve tubes; 
10, bast fibers; 11, pith cells; 12, med- 
ullary plates. (Courtesy of American 
Museum of Natural History.) 260 
THE BEAN 
fore, a dicotyledon. Most of our flowering plants are dicoty- 
ledons. 
The arrangement of the tissues in the stem of any dicotyle- 
donous plant is the same as it is in the bean stem; and the 
manner of growth is the same. A tissue is a group of cells 
similar in structure and in function. Beginning at the surface, 
the order of tissues in the bean stem are the epidermis, the 
cortex or corky layer, the bast fibers, cambium (the region 
where growing occurs), wood fibers, pith. These tissues lie in 
rings one within another, except that the pith occupies all 
the central region of the stem. At an early stage in the 
growth of the stem there are present small masses of wood 
fibers, cambium, and bast fibers. These are called fibro- 
vascular bundles. When more wood is added it is formed in 
the inside of the ring of cambium. When bast or cortex is 
added it is formed on the outside of the cambium. All 
the water passes up the stem in the wood tissue. All 
the liquid food created in the leaves and carried down- 
ward for use by the plant is carried in the cortex or bark 
region. 
THE LEAVES 
The leaves of the bean plant are compound leaves of three 
leaflets each. The compound leaves occur in pairs alternating 
by pairs up the stem. The fibrovascular bundles of the stem 
extend through the leaves. Their presence is visible as the 
midrib and veins. 
Characteristic tissues of the leaf are the upper and lower 
epidermis and a layer of narrow cells set on end (called pali- 
sade cells). There are loosely connected rounded green cells, 
and air-pores, connecting the interior spaces with the out- 
side air. Here, as in the leaf of com and in other green 
leaves, the chlorophyll-bearing leaves produce the carbo- 
hydrate. THE BEAN 
261 
THE FLOWER 
The flowers of the bean plant develop from clusters of 
buds. The parts of the flower from the margin to the center 
are, the calyx, the corolla, the stamens, and the pistil. The 
calyx is made up of fine leaf-like sepals. This set of organs 
remains on the flower stalk while the fruit is developing. The 
corolla is made up of five petals. The petals are of three 
shapes. A large petal is expanded into a “standard” or 
“banner.” At its base, and cupped toward the standard on 
Fig. 129. Diagram Showing Direction of Flow of 
Liquids and Gases in Photosynthesis. 
(Courtesy of American Museum of Natural History.) 
the opposite side of the stamens and pistil, are two petals 
joined together at their margins to resemble the keel of a 
boat. This keel incloses and conceals the stamens and pistil. 
At either side of the keel, but in the circle of parts of the 
corolla, are two petals resembling “wings.” There are five 
sepals and five petals. 
The stamens are ten in number. Nine of the stamens are 
joined by their stalks or filaments the greater part of their 
length, forming a sheath or trough in which is inclosed the 262 
THE BEAN 
most of the long flattened boomerang-shaped pistil. The 
tenth stamen is free to its base, but lies in the narrow crevice 
formed by the edges of the trough. The basal portion of the 
pistil is the flattened ovary, containing four to ten ovules 
which later develop into seeds. Above the ovary is the 
style, bent over toward the standard at nearly right angles. 
Near the top on the in- 
ner side is the stigma. 
The stigma is rough 
and is covered with a 
slightly gummy sub- 
stance. All over the 
pistil is a covering of 
short plant hairs. 
The flower precedes 
the formation of the 
fruit or bean pod. In 
fact, we have already 
noted the similarity in 
shape and internal 
structure between the 
bean pod and the pistil. 
It is clear that the 
meaning of the flower is 
as a producer of the 
fruit. But in a sense 
all the organs contrib- 
ute their part to the creation of the fruit. 
In Chapter XVII reference was made to the importance of 
the relation between the flowers of plants and certain species 
of insects. So general are the manifestations of adaptations 
of the form and color of the parts of flowers to the activities 
of insects that we may be sure that any flower with a con- 
spicuous corolla is visited by insects. Bumble bees visit 
bean blossoms as well as many other species. When a bee 
Fig. 130. Flower of Bean Plant. 
Section through middle of flower showing 
calyx, corolla, stamens, and ovary. (Drawn 
by Maud H. Purdy.) THE BEAN 
263 
alights upon the wing of a bean blossom the trough of sta- 
mens spreads slightly from the single stamen. The proboscis 
or “tongue” of the bee is then thrust into the trough between 
the ovary and the stamens where nectar has been formed. 
The tongue and the bristle-covered head and back of the 
bee comes into contact with the pollen of the stamens, and is 
entangled there. The next flower visited by the bee is likely 
to receive on its stigma a few grains of pollen from an en- 
Fig. 131. Diagrammatic Section of Flower to Show Fertilization. 
(Courtesy of American Museum of Natural History.) 
tirely different bean blossom. The process by which pollen 
is transferred from the stamens to the pistil of the same 
species of plant is called pollination. 
It is very probable that pollination in many bean blossoms 
occurs without transfer of pollen out of the blossom. That is 
to say, self-pollination takes place. But this is not easy, 
since the stigma of the pistil is beyond the reach of the an- 
thers where the pollen is produced. Better seeds and hence 264 
THE BEAN 
better plants are produced when cross-pollination occurs, 
that is, the transfer of pollen from one flower to the stigma of 
another flower. When one or more grains of pollen are de- 
posited on a stigma that is ready to receive them, the process 
of pollination is said to be complete. The process of fertiliza- 
tion or the production of seed then begins. 
Pollen grains are inclosed in heavy walls with thin places, 
germ-pores, through which the contents of the pollen grain 
may emerge in the process of germination. The germination 
of a pollen grain consists in the vegetative or growing cell in the 
pollen grain pushing out through one of the germ-pores, and 
forming the pollen tube. The pollen tube grows down the 
canal of the style. The generative cell of the pollen grain 
follows into the pollen tube and divides into two male gametes. 
The pollen tube grows down into the ovary until it reaches 
the ovules. There might be many more pollen tubes growing 
into the ovary than there are ovules, but when one pollen 
tube reaches one ovule no more can take part in the fertiliza- 
tion of that particular ovule. 
When the pollen tube reaches the center of the ovule where 
the female plant is located the end of the pollen tube breaks 
open, and one male gamete unites with the egg-nucleus in the 
female plant. The product of this union of the two nuclei is 
called the zygote, a term we learned in Chapters XIX and 
XX. The zygote by division forms the embryo. By special 
grouping of cells the several organs of the embryo are formed. 
Food material is formed in the endosperm of the seed, and 
within two weeks after pollination the bean pods are large 
enough to serve as food. A few weeks more and the seeds 
are fully developed, dried and ready to start the growth of 
bean plants for the next season. CHAPTER XXIII 
THE FORESTS 
In fairy tales and in romantic literature forests stand for un- 
traveled regions of mystery where wood nymphs flit through 
the dark shadows sometimes protecting a human wanderer, 
but oftener leading him into trouble. Mythical wolves with 
gleaming eyes, as well as substantial ones with hungry stom- 
achs and sharp teeth, roam the forests in the bed-time stories 
of our childhood. As we grow older we love to read of robbers 
sallying forth from the depths of the forest to rob the rich 
and give to the poor. 
Not only in story, but even in actual life in the present 
century, the forest has its charm for nearly everybody. 
Young people especially like to run, and loiter, through the 
woods, hunting early flowers in the spring, eating berries in 
the summer time, and gathering nuts in the autumn. Most 
of the older people like some of this too. There are others 
from the city who worry about the polish on their shoes. 
But to the men and women who live in and by means of the 
forests there may be a subconscious feeling of freedom in the 
life, but there is more of hard work and matter-of-fact con- 
cern about whether the forest will make them a living. 
There is the day-to-day labor of protecting the forest, of 
selecting for the cutting of trees for lumber for the house 
fires, of brush burning, and of resetting young trees. Thus, 
the forests are sources of pleasure and of livelihood. 
When the early settlers of the country endeavored to 
establish their farms, they cleared the land of trees. They 
built houses of logs, because logs wrere cheap. Besides there 
were few or no saw-mills available. The river bottoms were 
265 266 
THE FORESTS 
the first lands to be cleared, because travel was along the 
rivers. Forests were regarded as obstacles to be overcome, 
and not at all as sources of wealth. The wastefulness of our 
countrymen in dealing with the forests did not seem wasteful 
until lumber began to be scarce in certain regions, and until 
some of the effects of stripping trees from the higher lands 
away from the rivers became apparent. 
In so great a problem as that of conserving our natural 
Fig. 132. Wasteful Methods in Lumbering. 
(Keystone View Company, New York.) 
resources in forests, we should not ascribe altogether to 
previous wastefulness the existing great cost of building 
materials. In the seventeenth century there were very few 
people here. In the twentieth century we now have over one 
hundred millions of human beings in our country. If the 
needs of our present population were of the same character as 
those of our predecessors three hundred years ago, there 
might be no scarcity even now. But within the last one 
hundred years we have developed an immense industrial THE FORESTS 
267 
system. The multitude of uses for wood is so great as to be 
beyond the ordinary powers of computation and description. 
A few details will be useful to suggest to your understanding 
the immense field of the industrial uses of wood. Factories 
produce elaborate and numerous farm implements, as against 
a few simple kinds one hundred years ago. The whole sys- 
tem of transportation is almost a new thing within one 
Fig. 133. Transportation of Logs to the Sawmill. 
(Courtesy of American Museum of Natural History.) 
hundred years. Wood goes into the building of fleets of giant 
steamships, trains of cars, railroad ties, stations, and also 
the numerous groups of municipal and suburban transporta- 
tion systems, and the trucks of private companies. 
The cities of homes and the thousands upon thousands of 
square miles of commercial houses consume enormous 
quantities of lumber. The factories themselves in their own 268 
THE FORESTS 
structures comprise an infinitely great quantity. Then 
nearly eveiy family takes at least one newspaper, and this is 
made of wood fiber. Great stretches of forest go into the 
Fig. 134. Evergreens and Hardwoods in Adirondack^. 
Heavy stand of trees sustained by dense mat of decaying vege- 
tation holding water supply. (Courtesy of The New York 
State College of Forestry, at Syracuse.) 
manufacture of paper. Furniture in the houses and numer- 
ous articles of use there are also made of wood. THE FORESTS 
269 
Our industrial age has changed luxuries into actual needs 
and has developed new needs not dreamed of by our fore- 
fathers. One hundred years ago one small house was enough 
for a family. Now some families have several, and all of them 
expensive and very large, besides the hotels and clubs which 
our greater activities make useful. Luxurious appointments 
and the need of traveling have their effect in increasing trans- 
portation by rail and by automobile. The richer the nation 
becomes the more things we need or think we need for work, 
Fig. 135. Forest too Heavily Cut. 
Will lead to wearing down of soil. (Courtesy of The New York State 
College of Forestry, at Syracuse.) 
for leisure and for play. Is it any wonder that the forests 
have been devastated? 
There are two phases in the problem of restoring our for- 
ests. One is to make the growth of trees throughout the 
country at least equal to the quantity used each year and if 
possible to regain something of what has been consumed in 
the industrial age. The other phase is to so place the new 
forests of trees that they will hold the water of the hills and 
mountains, conserving it in a steady flow for the water supply 
of cities, for irrigation and for hydro-electric power. The 270 
THE FORESTS 
solution of both phases of the problem can be approached at 
the same time. 
It was not until 1875 that the United States began to con- 
sider this problem officially. We then began the policy of 
setting aside certain tracts of forest lands in the domain as 
permanent forest reservations. In the prairie regions of the 
middle West not yet claimed by settlers there were at regular 
intervals quarter-sections of land (160 acres) set aside as 
“timber quarters” to be planted to timber by a settler before 
he could receive a deed to his “claim.” By far the more 
effective government provision was in reserving virgin forests. 
The setting aside of forest reserves began under the ad- 
ministration of President Harrison, and continued through 
the second administration of President Cleveland, and the 
administration of President McKinley. But in the admin- 
istration of President Roosevelt the movement for forest con- 
servation became a national enthusiasm. Many of the states 
entered the movement and established their own forest re- 
serves. Municipalities took up the cause of forest conserva- 
tion, for example, the City of New York which planted young 
trees around its great reservoirs one hundred miles from the 
city itself. President Roosevelt’s great love of nature and 
thorough knowledge of its forces contributed much to the effec- 
tiveness of the campaign of education for forest conservation. 
Among other things he did was to request the publication in 
the National Geographic Magazine of a series of photographs 
of the mountains of China. These mountains had been 
stripped of their trees, and the sides were gullied deep with 
the unchecked torrents of rains. China had robbed itself of 
its wealth of forests, and had made it possible not only for its 
wealth of fruitful soil to be washed away, but also to lose its 
rains in floods that devastated property and caused immense 
loss in human lives. The misfortune of China was an object 
lesson. 
The principle of forest conservation is not to prevent the THE FORESTS 
271 
cutting of trees, but rather to make the forest produce effi- 
ciently, just as we expect a field to produce corn or wheat 
efficiently. Federal and state forests are leased to individuals 
and companies. Forest rangers and inspectors employed by 
the government watch for fires and also to see that the law is 
not violated. The different species of trees attain their 
Fig. 136. California Redwood. 
(Keystone View Company, New York.) 
maximum growth or their most productive growth, some in 
thirty years, and some in fifty years. Others require one 
hundred years to mature. The giant redwoods now standing 
are known from comparison with those already cut to be not 
less than two thousand years of age. The age of a tree is 
ascertained by the number of annual rings shown in a cross 
section. Trees that have done their best should be cut. 
Otherwise they die and become a commercial loss. Under 272 
THE FORESTS 
the most careful management, for every mature tree cut and 
turned into useful products a young tree is planted in its 
place. Or at least the natural tendency of trees to scatter 
their seeds over unoccupied territory is encouraged. Natural 
reforestation, however, is checked in regions where the gov- 
ernment permits companies to pasture sheep and cattle. 
No matter how successful the federal and state govern- 
ments might be in making their forest reserves produce 
efficiently, our needs would still fail to be met. It has been 
estimated that to-day we are cutting three times as much 
timber as we are renewing by growth. Even at that, we 
obtain great quantities of wood from Canada which is still 
immensely rich in forests. Our hope will come through the 
extension of education about forest growing to those who 
have in charge the great tracts of unused lands or lands that 
are unproductive of ordinary crops. 
It is known that land that will not produce any of the 
ordinary cereal crops will produce trees. Most farms have 
parts which are unprofitable to cultivate in ordinary crops, 
and constitute a waste in the economy of the farm. Agricul- 
tural colleges, schools of forestry and the government itself 
are trying to make it clear to farmers that what are called 
“wood lots” on a farm not only improve the land, but even 
yield a considerable profit. If the movement to establish 
wood lots of several acres on every farm gains headway under 
the stimulus of scientific agriculture, the chances are good 
that for a considerable time trees will be made to yield more 
efficiently than is possible under the non-personal, govern- 
mental control of the enormous tracts in the forest reserves. 
We are likely to think that forests produce only lumber. 
At one time that was all they did produce. But our industrial 
age has worked out many other uses. The wasted tops of 
trees as well as the logs of the soft woods, such as spruce, 
poplar and larch, are used in the manufacture of paper. 
The yellow pine of the Southern states produces enormous THE FORESTS 
273 
quantities of turpentine and rosin. The waste material of 
saw mills, instead of being thrown into the river as formerly, 
is now subjected to great heat under pressure in distilling 
Fig. 137. Road Through Aspens. 
Showing branches seeking maximum of light. (Courtesy of 
American Museum of Natural History.) 
tanks and made to yield large quantities of wood-alcohol, 
turpentine, formaldehyde, tar, creosote and other less well 
known products. We may secure all these, s'distan ces, and 274 
THE FORESTS 
still have a residue of charcoal. The science of industrial 
chemistry may discover other ways to produce wood products 
useful to man. 
Forests are producing richly even under the care being 
given them. We know, however, that the product of forest 
trees will be increased still more when we begin to give the 
same care to forest trees that is commonly given to fruit trees. 
Trees must have adequate 
light or they will die. With 
sufficient light to set in 
motion the process of pho- 
tosynthesis in the leaves 
the tree will grow the more 
rapidly and yield a greater 
quantity of wood. If the 
light admitted to a forest is 
too great, grass will begin 
to grow on the forest floor, 
and the mineral substances 
needed by the trees will be 
wasted in growing grass. If 
grass is grown, there is a 
temptation to the farmer to 
allow cattle and sheep to 
graze in the forest. If this 
is done, considerable loss is 
liable to occur, for the grazing and browsing destroy seedling 
trees and injure other young trees. It requires good judg- 
ment to decide whether to be content with less profit on the 
trees, or a possible gain in the weight of the live stock. 
High winds, and the ravages of insects, especially tent 
caterpillars and other insects that attack the plant labora- 
tories, the leaves, cause a loss that cannot be easily deter- 
mined, but is nevertheless real. Bracket fungi and many 
bacterial diseases attack trees through wounds they have 
Fig. 138. Forest Observer's Tower. 
(Courtesy of Wisconsin Conservation 
Commission.) TIIE FORESTS 
275 
received. The loss from this source is also considerable. 
But the losses by fire are the greatest of nil, and they can be 
estimated. It is represented not only in the actual loss of 
the existing stand of trees, but also in the possible cumulative 
return of all the years intervening between the fire and the 
time when complete restoration of the forest can be attained. 
Even to-day with all the protection we try to give the forests, 
the destruction of trees by fire in some years exceeds the 
entire years’ cutting. 
So important is this matter of protection against fire that 
GOING FISHING? 
THE FINEST TROUT STREAMS AND LAKES, THE BEST HUNT- 
ING GROUNDS AND THE MOST BEAUTIFUL CAMPING 
PLACES IN AMERICA ARE TO BE FOUND IN WISCONSIN 
PRESERVE THE FISHING AND HUNTING 
IN THE NORTH WOODS BY HELPING 
US PREVENT FOREST FIRES 
LIGHTED MATCHES, CIGARS AND CIGARETTES ARE 
DANGEROUS. PUT OUT YOUR CAMP FIRES 
BEFORE LEAVING 
KEEP THE FORESTS GREEN DON’T BUILD BONFIRES 
Wisconsin Conservation .Commission 
Fig. 139. How One State Advertises the 
Desirability of Protecting Forests. (Cour- 
tesy of Wisconsin Conservation Commission.) 
high towers are built on mountain or hill tops for observers. 
The towers are connected by telephone with the district 
station. Airplanes are now being used for scouting purposes 
to supplement the slower process of scouting on horseback. 
In the summer of 1908 the author had the odd experience 
of being in the midst of a serious forest fire in the vicinity of 
the Tuolumne Redwood Forest in California without realiz- 
ing at first the menacing character of what appeared to be a 
small smoiddering fire at one side of the mountain road. But 
soon forest rangers were seen rushing along the road on their 276 
THE FORESTS 
horses seeking news about the condition of the fire at some 
distant point. And suddenly a large pine tree burst into flame 
in a place where to all appearances there had been no fire at 
all. Nearby was a ranch house and barns that the rangers 
said would surely be consumed in a few hours. 
The dangerous feature of the fire was the fact that it 
was mostly underground. Sometimes for several feet be- 
neath the surface a forest fire “mulls” within the mass of 
semi-decayed pine needles and other decaying or dead vege- 
tation, here and there following a root or air space under- 
ground. The tremendous heat released in the slow burning 
will set a green tree on fire and consume it. A forest fire 
cannot be extinguished by ordinary means. It must be 
headed off by burning fire guards in spaces where control can 
be organized. Or the fire must be “hemmed in” by a road- 
way, or by a stream. The particular fire observed was 
threatening the national redwood forest. In the middle of 
August the fire was several miles from the forest of prize 
redwoods, like one shown in Fig. 136. The fire did not reach 
the redwoods, but the rangers were busy six weeks before 
they were able to completely head it off, and force the fire to 
burn itself out. CHAPTER XXIV 
PLANT BREEDING 
Plant breeding consists of a more or less systematic effort 
to improve existing varieties of plants and to develop new 
varieties. Everyone of the cultivated useful plants we have 
to-day has been developed to its present productiveness by 
long continued attention to the principles of plant breeding. 
Among familiar food plants which show the most striking 
changes from primitive uncultivated ancestors are the apple, 
the potato and the Indian corn. 
For hundreds of years these and many other plants useful 
to man have been brought out from wild nature into a state 
of cultivation, and have been improved in numerous ways. 
But the principles employed by plant breeders for a long time 
were little understood. Not until the beginning of the pres- 
ent century, when scientific plant breeders came to under- 
stand principles of heredity that had been discovered by 
Gregor Mendel, an Austrian monk (Chapters XVI, XXXIX) 
did plant breeding as a truly scientific undertaking attain a 
high state of efficiency. If by patient practical efforts made 
by fruit growers, gardeners, farmers, and experiment stations 
we have the vast supplies of plant food and plant products 
for clothing available at the present time. Our imagination 
may picture still greater stores of food and clothing when 
scientific principles are thoroughly worked out and applied. 
And when the principles of plant breeding are applied to new 
varieties still reposing untried in wild nature, we may see 
the development of large additional stores for the future. 
Some of our useful cultivated plants may be traced back 
beyond their recorded history. The white potato came from 
277 278 
PLANT BREEDING 
a species of the genus Solatium, a native of Chile. Members 
of the same genus are the egg-plant, the nightshade and the 
tomato. The primitive ancestor of the numerous varieties of 
white potatoes was a plant that had small tubers (a type of 
underground stem) growing from branches at the base of the 
erect stem. By some chance unknown to us to-day, this 
species came under cultivation. The tubers developed as the 
food storage portion of the plant, and by selection of the 
specimens that showed desired 
qualities, the several varieties 
were created. 
The specialization of the po- 
tato has become so great that 
the seeds are not able to re- 
produce the species, although 
many seeds are produced from 
the well-known white flowers. 
Reproduction is brought about 
by planting pieces of potato 
tuber that bear an “eye” or 
bud surrounded by bud scales. 
A new plant develops from the 
bud. 
There are thought to be three European wild species that 
gave rise to all the varieties of apples, both European and 
American. The primitive apple may be demonstrated even 
to-day in actual experience. This is often done accidentally 
by the growth of apple trees from seeds. The apple seed 
probably never reproduces the variety of apple from which 
the seed comes. These “seedling” apple trees generally pro- 
duce small, extremely sour and unpalatable fruits, and the 
trees themselves are small. 
When more trees of a desired variety are to be created an- 
other method of propagation is resorted to. In principle it is 
the same as creating new potato plants by planting a piece of 
Fig. 140. White Potato Plant. 
Part of top not showing. (Cour- 
tesy of American Museum of 
Natural History.) PLANT BREEDING 
279 
a tuber. A twig of Baldwin apple, for example, is cut from 
a parent tree. By various devices this twig may be cut and 
trimmed to fit the prepared stump of a vigorous young tree 
that has grown from a seed. The two are bound with 
gummed tape and fixed in wax to ensure the two parts grow- 
ing together, and becoming in effect one tree. The new tree is 
nourished through the roots of a seedling tree, but the fruit 
borne will be the variety of the top or budding portion. This 
Fig. 141. Seedling Apple and Baldwin Apple. 
Showing a common difference in size between seedling apples 
and grafted varieties. (Drawn by Maud H. Purdy.) 
method of propagation of apple trees is called grafting. It 
is employed in many species of edible fruit trees, or roses and 
other species of cultivated plants. 
Plants in many instances are capable of forming new gen- 
erations without the aid of reproduction by flowers and seeds. 
Very often a twig may be cut and planted, and a new plant 
with roots soon established. Well-known examples of this 
kind are geraniums and willows. The hardwood trees, like 
oaks, easily regrow stems and leaves from a stump, even in 
cases where the original tree is quite large and old. However, 
oak twigs will not produce new trees if planted. Almost any 
weed will reproduce a complete plant from a portion of a root. 280 
PLANT BREEDING 
This capacity needs to he possessed by plants that become 
weeds, on account of the top portion being destroyed so 
often. Leaves sometimes reproduce the whole plant, as in 
the begonias. A great number of plants by possessing under- 
ground stems, like the tubers, the bulbs of onions or lilies, and 
the root-stocks of horse radish, not only start new generations, 
but also start them quickly by the aid of large quantities of 
stored food. All of these portions of plants are useful in 
reproduction in maintaining a measure of stability in the 
varieties desired when once 
they have been secured. 
Plants, however, are not 
stable. Variability or the 
capacity to change is a basic 
fact in nature. Plants espe- 
cially are manifesting this 
capacity in the shapes, sizes 
and detailed structure of the 
leaves of a tree, in the mark- 
ings and colors of flowers, in 
the size and numbers of seeds 
in fruits, and it is thought 
even in the miscroscopic and ultra-microscopic organization 
of the germs of seeds. Variation is the usual phenomenon 
in growth and reproduction. 
There are many points in connection with the influences 
in nature that tend to stimulate and modify variations. 
Some of these points we may easily notice. For example, 
plants vary in relation to the source of light that reaches 
them. They vary according to the soil in which they grow, 
according to the cultivation they receive, and according to 
the number and kind of other plants growing near them. 
The determination of what many variations will be lies, in the 
judgment of some scientists, within the germ of the seed itself. 
Another occasion for variation in plants is observed in 
(Courtesy of American Museum of 
Natural History.) 
Fig. 142. Methods of Grafting. PLANT BREEDING 
281 
their need of adapting themselves to different conditions of 
all sorts. Some of these conditions may be quite unusual, 
such as a considerable change of climate with differences in 
soil and amount of water. The capacity of the plant to 
adapt itself to the new conditions may be demonstrated in 
the appearance of plants that look quite different from those 
inhabiting the customary place. 
Experimentation has shown that sexual reproduction in 
plants brings into existence a flood of variations. These 
variations are doubtless induced by combinations of the 
Fig. 143. Begonia Leaf with Roots. 
Roots growing from cut areas. (Drawn by Maud H. Purdy.) 
characteristics of the male and female cells taking part in the 
process. This variety of result is the more likely to happen if 
the uniting cells originate in entirely different plants of the 
same species. 
Those who experiment in producing new varieties of plants 
know the foregoing facts. They take advantage of the facts 
and are constantly on the lookout for new variations in the 
direction they desire development to take. Although the 
variability of plants is the factor on which the experimenter 
works, yet it is what the experimenter thinks he is striving 
for that really commands the situation. What he thinks, of 
course, is limited by the probable ultimate capacity of the 
species of plant to become. 282 
PLANT BREEDING 
It would be incorrect to say that all the plant breeder has 
to do is to think out what he desires, and then to proceed to 
manipulate the adaptable plant, and finally accomplish the 
end sought. Plants occasionally vary in large and conspic- 
uous ways. Variations sometimes appear of so striking a 
character as to look like a new species. In fact, the observa- 
tions of the Dutch botanist, DeVries, on the variations in 
the evening primrose indicate clearly that new species arise 
often by way of large, rather than by small differences from 
Fig. 144. Mountain Pine in the Tyrol. 
Showing effect of high altitude on growth of vegetation. (Kerner & Oliver: 
The Natural History of Plants; Henry Holt and Company.) 
the regular form or type of the species. These sudden ap- 
pearances of large variations called sports, easily serve as the 
basis of further progress in the creation of varieties. They 
would also tend to modify what an experimenter might 
think as the end sought. One of these sudden and unexpected 
variations became the “wealthy” apple. Once the wealthy 
apple appeared, the problem would be to retain it as an 
established variety. In the case of a new variety of apple 
this is not so difficult an undertaking as it might be if it were 
necessary to depend on sexual reproduction for new genera- 
tions. Grafts continue the variety. But there is a strong PLANT BREEDING 
283 
tendency for sports to hold more or less firmly to the new 
character, once it has appeared, even where sexual reproduc- 
tion is the method of propagation employed. 
Nevertheless, variation is so common a factor in plant life 
that nothing can be left to chance in plant breeding. The 
experimenter may desire to hold firmly to an attained variety. 
In that case he must eliminate all variations that tend to 
dissipate and scatter the qualities he has strived to establish. 
Fig. 145. Plumcot Fruit. 
(From Harwood: New Creations of Plant Life; The Macmillan Company.) 
It may be that he is hoping for certain improvements on what 
he has already attained. If that is true, he must be on the 
watch for characters that point in the desired direction, and 
he must eliminate by destruction or separation the plants 
that are varying in unprofitable directions. It is said that 
Mr. Luther Burbank, the well-known California experimenter, 
possesses phenomenal skill in detecting the undesired va- 
riations early in the life of the individual plants, and saves 
much time by getting rid of them at once. 284 
PLANT BREEDING 
The name of Burbank is connected with a number of new 
varieties of plants created by applying certain principles. 
One principle he applies is hybridization. This is the crossing 
of species. This principle has often been used, because it 
releases a great number of variations some of which may be 
valuable. Burbank’s most famous experiment in this line 
was in the production of the plumcot, a hybrid of the plum 
and the apricot. The method employed in hybridization is 
to remove the stamens of a flower before they are ready to 
yield pollen, and then to 
protect the pistil from be- 
ing pollinated by covering 
the branch with a paper 
bag. When the stigma of 
the pistil is ready to receive 
pollen, pollen is taken from 
the flower of a plant with 
which crossing is desired, 
and the pollen is dusted on 
the stigma, and covered up 
once more. The method of 
work followed by Burbank 
has been described by Pro- 
fessor L. H. Bailey of Cor- 
nell University, who himself 
is a successful experimenter 
with plants. In “Plant Breeding” Professor Bailey writes of 
Burbank: “He cultivates with personal care, multiplies the 
stock to the limit of his capacities, scrutinizes every variation, 
hybridizes indiscriminately, saves the seeds of the forms that 
most appeal to him, sows again, hybridizes and selects again, 
uproots by the hundreds and thousands, extracts the delights 
from every new experience, and now and then saves out a 
form that he thinks to be worth introducing to the public.” 
The quotation will serve to give the student an idea of 
Fig. 146. Branch of Spineless Cac- 
tus. Showing the effect of reserve 
supply of stored food in cactus. 
(Photographed on shed in garden of 
Luther Burbank.) PLANT BREEDING 
285 
the method of work of most other experimenters in this 
line. 
There are three objects in the minds of plant breeders 
that are of wide application. The first of these is the im- 
provement of existing types of plants; the second is the crea- 
tion of new varieties; the third is the breeding for what are 
called “unit characters” that have each in itself a particular 
value. The first two have been discussed. The third object 
has had its best consideration under the stimulus of the 
scientific work of Gregor Mendel (Chapters XVI, XXXIX). 
Mendel’s experiments showed that characters are inherited 
singly, or as units, their presence or absence in a generation 
not being influenced by the presence or absence of any other 
character. For example, a head of wheat could be short and 
bearded or long and bearded, or short and smooth, or long 
and smooth. The unit character of resistance to rust, or of 
resistance to drought would follow the same rule. However, 
by means of hybridization between varieties new varieties of 
wheat or other plants can be produced that are adapted to 
particular regions. In this direction important progress is 
being made. 
Thus, plant breeding has its purely technical basis, as well 
as its social and economic bearing. There may be plant 
breeders who are interested chiefly in manipulating the 
plastic organization of the plant. But the response scien- 
tific students may expect from the people is based on their 
success in making scientific work in plants contribute to the 
welfare of mankind. CHAPTER XXV 
THE FARM, A COMPREHENSIVE BIOLOGICAL UNIT 
The indication that the farm is a biological unit is to be 
found in the story of pioneer life in America. It was a bio- 
logical unit for man at that time. It still is a fundamental 
grouping of biological factors in the life of mankind. By the 
term biological unit we understand a group of organisms, 
plants and animals, living in nature entirely or in part in 
such relation that the life of one kind contributes to the life 
of other kinds. 
On the pioneer farm the family was surrounded by primi- 
tive nature. The forest produced lumber or logs and shingles 
for the house, the barns and other structures. From certain 
species of trees the primitive farmer also obtained dye-stuff, 
as from the inner bark of the yellow oak, tanning agencies 
for the preparation of leather, as from the hemlock bark, 
medicines, as from the root bark of the sassafras tree and 
from numerous annual plants. From the ashes of all trees he 
obtained the lye by which animal fat was made into soap. 
From the bark of hemp, rope was made; from the bark of the 
flax plant linen was made. Whether the wood of the farm 
was burned or whether it rotted, the mineral compounds in it 
in time became a portion of the soil again, thereby maintain- 
ing the resources of the soil. 
Within the forests numerous species of animals lived. 
In some instances these animals served as food for man. Of 
these there were rabbits, squirrels, grouse. Other animals 
lived upon the animals and plants in nature, and sometimes 
on the organisms which man was engaged in protecting for 
his own use and profit. These preying animals were foxes, 
wild cats, bears. 
286 THE FARM, A BIOLOGICAL UNIT 
287 
The forest harbors many other species of animals and also 
species of plants. The living together of all these species 
create numerous biological situations of interdependence. 
For example, the birds live under the protection of the trees 
and the underbrush. The shadows and the material of the 
forest help to conceal them. In the branches and in pro- 
tected places the birds lay their eggs, and bring up their 
young. 
In the forest also are to be found at least a portion of the 
From Drawing showing Governor Bradford's House. (© Keystone 
View Company, New York.) 
Fig. 147. The First Clearing in Plymouth Colony. 
food on which the birds live. Insects live on the forest vege- 
tation, and are preyed upon by the birds. Certain species of 
birds sally forth to the adjacent fields, preying upon insects 
which otherwise would prey upon the farm vegetation, the 
gardens, the field crops, the fruit trees and their fruit. 
When the first farms were carved out of the wilderness the 
cultivated patches frequently produced scantily, because 
ground that produces trees is often too poor for farm crops. 
Besides, there are numerous stumps which made cultivation 288 
THE FARM, A BIOLOGICAL UNIT 
tedious work. The plowing and the cultivation of the farm 
crops stirred up and covered over the mass of partly decayed 
leaves and other debris which were spread over the forest 
floor. When this became thoroughly transformed into min- 
eral compounds, and when the farm crop remains themselves 
were rotted, the soil was more adaptable to the successful 
growth of crops. The powdered earth also served as a 
retaining blanket for the moisture below. Excessive organic 
debris tends to the formation of excessive quantities of humus 
Showing variety of productive vegetation. (Keystone View Com- 
pany, New York.) 
Fig. 148. Improved Farm. 
acids. These are counteracted by the lime thrown upon the 
soil. Thus “sweetening” takes place, and more successful 
cropping. 
After many years of farming in the clearing grounds, the 
forests gradually disappeared, the change being accompanied 
frequently by considerable waste of organic wealth. Then 
the richness of the soil sometimes began to fail. The crops 
that the land produces were often carried far from the land, 
as when hay was sold in the city, or when corn, wheat and THE FARM, A BIOLOGICAL UNIT 
289 
rye were carried to market. And also when corn and liay 
were fed to the farm animals, the inorganic riches of the soil 
were in part transformed into organic tissue in the animal, 
and in part were cast out from their bodies as indigestible 
material. 
The soil then had to be restored to its former condition. 
This was done by means of spreading various kinds of fer- 
tilizer on the soil, and subsequent ly plowing it in. The main- 
tenance of the mineral compounds in the soil is done some- 
times at considerable cost, but the results usually justify the 
expenditure. 
Whatever the source of the fertilizer, the chemical com- 
pounds formed in it are what the soil lacks, or has lost. In a 
sense, therefore, what has been carried away from the soil 
through the crops sold or eaten up by domesticated animals, 
is now returned to it. Such fertilizers as barn manure, and 
some forms of commercial fertilizers made from the wastes 
of abattoirs (places where food animals are prepared for the 
market) make the biological return to the original soil source. 
It is an interesting fact that a farm which is organized 
to yield the most satisfactory income is one on which the 
food produced is consumed there by the farm animals. 
The test of this is observed when a farm product, such 
as corn, is so cheap that it does not pay to raise it if it is 
to be sold and carried away. But if the corn is fed to hogs, 
on the farm, there is a profit made on the corn when the hogs 
are sold in the market. Likewise, when hay or rye are raised, 
it is more profitable to have horses, cattle and chickens 
(Chapter XVI) on the farm eat what can be eaten by them. 
There is another charge against the cost of living elim- 
inated, if in the process of making the farm create food for 
animals to consume, there are enough varieties of plants 
produced to maintain the varieties of food required by man 
himself. In primitive days this was nearly possible even in 
temperate regions. The chief reason it is not possible to-day 290 
THE FARM, A BIOLOGICAL UNIT 
for the farm in temperate regions to produce what a family re- 
quires in food is because our needs, fundamental and those 
that develop by the extension of our likes, have increased 
enormously. Then, too, farming itself has become specialized 
in some regions so greatly that the biologically balanced farm 
is not as common as it was once. We now have potato farms, 
wheat farms, strawberry farms or general garden vegetable 
farms, and only enough animals to care for the heavy work, 
and even the horses are 
often replaced by the 
gasoline tractor. 
One of the conspicuous 
factors in the life rela- 
tions on a farm is the dis- 
persal of fruits and seeds. 
All the cultivated vari- 
eties have seeds that re- 
quire the hand of man to 
distribute. The seeds of 
trees are dispersed by 
the wind or by animals, 
pines and maples by the 
wind and the heavy 
nuts by squirrels chiefly. 
The plants which are 
known as weeds attain a 
large measure of their 
success by the fact that 
their seeds are dispersed widely by the wind and by stick- 
ing to the hair of farm animals. 
But no matter how satisfactorily the biological balance is 
maintained on a farm, there is more food produced than can 
be consumed there. This food finds its way to the market. 
Its function is to feed animals and human beings. There is 
no other reason for producing food. If the farmer who pro- 
Fig. 149. Dispersal of Dandelion 
Fruits. (Courtesy of American Mu- 
seum of Natural History.) THE FARM, A RIOLOGICAL UNIT 
291 
duces this food for a use so important is not fairly compen- 
sated for his work of creating the food, it may be because 
some other groups of persons are trying to secure great re- 
ward for performing some minor service, or for no service at 
all. There are those who live honestly by carrying food from 
Fig. 150. Dispersal of Seeds and Fruits. 
A, ailanthus; B, wild geranium; C, bidens; D, maple; E, 
burdock. (From Kemer & Oliver: The Natural History of 
Plants; Henry Holt and Company.) 
the farm to the consumer and distributing it. But there are 
many others who exist as economic “parasites” on the sus- 
tenance created by those who actually work; that is to say, 
there are numerous food brokers and speculators in the 
necessities of life. 
One effect of the existence of numerous groups who try 
to make a profit on the product of the farmer’s labor is to 292 
THE FARM, A BIOLOGICAL UNIT 
force him to accept less for the fruit of that labor. The 
outcome of all this with the resulting high cost to the con- 
sumer is to stop the flood of plenty at its source. An in- 
telligent farmer will cease producing food which it does not 
pay to create. lie will try his hand at making special kinds of 
food the price of which seems to be more satisfactory. In 
any event the quantity of food for the lower animals and 
ourselves tends to decrease, and the price tends to be higher, 
when the supply should 
actually be unlimited. 
The farm is without 
question the most impor- 
tant biological unit in 
existence, for reasons that 
have been given. It is 
also an extremely impor- 
tant social agency. This 
is because the farm cre- 
ates, transforms and ren- 
ders available, food for 
the race of human beings. 
Consider wheat. A 
field in Kansas is sowed 
to wheat in the fall of 
the year, or in the spring. 
In June, or July, the crop 
is ready for cutting. The 
harvester or binder reaps 
it. In either case the 
wheat is soon threshed, 
and the bushels of grain 
are stored in the farm granary or taken to the railroad 
for shipment, or stored in an elevator storage house, or 
shipped abroad. In time the wheat reaches the great milling 
center of Minneapolis, Minn., or European mills, where the 
Fig. 151. Grinding Wheat in the Great 
Minneapolis Mills. 
The broken particles of wheat are 
ground fourteen times before the proc- 
ess of grinding is completed. Dia- 
gram shows steel rollers at work. 
(Keystone View Company, New York). THE FARM, A BIOLOGICAL UNIT 
293 
various grades of flour are made. Transportation systems 
carry the flour all over the world. 
On account of the universal need for bread, the creation of 
food through the sowing and the growth of wheat is among 
the most important social activities known. Perhaps if boys 
on the farm realized how necessary the functions of the farm 
are to the very existence of millions of men, women and 
children they might come to be inspired by the thought of 
their opportunities. There would seem to be no greater 
source of inspira tion than the consciousness of creating some- 
thing that all the rest of mankind needs. Thus, it is possible 
for the farm to be the medium through which a boy or a girl 
may be educated. 
Once in a while we marvel that some of our leading citizens 
spent their early life on the farm, and, incidentally, had little 
opportunity to attend school or college. Perhaps many of us 
have accepted without question the notion that education 
consists in occupying a seat in school more or less steadily for 
eight to sixteen years, and then entering upon adult life with 
the limited capital in experience thus acquired. 
Life upon the farm offers a well rounded series of expe- 
riences. There is a theory of education that emphasizes the 
training of the senses. The farm affords experience material, 
and offers demands for the use of every one of the sense organs, 
especially the eyes, the ears, and the organs of touch. There is 
a theory of learning which stresses the discipline of the hands 
together with the correlation of these parts with the brain, anti 
the reaction of the great muscles anti the body as a whole to 
the factors in the environment. The farm offers a multitude of 
experiences in this field. It is conceivable that a farm boy or 
girl may go through life more or less ineffective anti helpless. 
But at least the opportunity to master the environment is 
available, and the stimidus to gain control of its elements 
exists in the necessity to live under conditions that are some- 
times hard indeed. Yet in spite of all these opportunities 294 
THE FARM, A BIOLOGICAL UNIT 
boys and girls have left the farms in large numbers, as soon 
as they were able to look after themselves. This has been a 
social problem of great concern to the country. As we see, 
it is also a clearly biological problem. 
The creation of food and the organization of productive 
relations on a farm cannot well be carried on by those who 
are content to stay on the farm while, as often happens, the 
more intelligent, independent and aggressive boys and girls 
go to the city “to seek their fortunes.” There is need of the 
highest intelligence among those who create food, clothing 
and shelter for mankind and thus make it possible for human 
beings to enjoy life, and work toward a higher civilization. 
There have been many “back to the farm” enterprises 
organized, but the problem is not yet solved. 
The farm cannot compete with the city in the variety of 
entertainment available. Hence, it will not help to try to 
outdo the city in this direction. Boys’ corn clubs have been 
organized, and wonderful results have been obtained by the 
members of these clubs in producing quantities of corn several 
times greater than those obtained in general farming. This 
enterprise has interested a great many boys. But it has also 
served to intensify the burden which constitutes the chief 
objection to farm life. This objection is hard, grinding work. 
Even the very men who, after attaining eminence in public 
life in the city, look back with enthusiastic recollection to 
their boyhood on the farm, actually left the farm because 
they could not endure the thought of wearing their lives out 
struggling as their fathers had done. The recollection of the 
gruelling work, like other unhappy experiences, had been 
softened by time. The really inherent features of native 
charm had stayed in their recollection at their true value. 
In the city, in commerce and in industry, the eight-hour 
day is accepted as proper and right by most employers. 
The farmer rises at five o’clock in the morning, and immedi- 
ately begins work at making fires, feeding the live stock, THE FARM, A BIOLOGICAL UNIT 
295 
milking, and in going over machinery in preparation for the 
day’s work. After breakfast he starts on the regular farm 
work of plowing, sowing, cultivating, or other of the numer- 
ous activities of the farm. In the city at the same time of 
day the machinist is barely on his way to work, while the pro- 
Fig. 152. Farmer Boy Bringing in Wood by Lantern Light. 
(© Keystone View Company, New York.) 
fessional man is sitting down to breakfast, or just getting up. 
About noon, with a glance at the sun, the farmer “turns 
out” for dinner. And the horses have their dinner. Atone 
o’clock he is at work again, continuing till sundown, or about 
seven-thirty or eight o’clock. The horses are fed, and 
“bedded” for the night. After supper, or before supper, the 296 
THE FARM, A BIOLOGICAL UNIT 
other farm animals are fed, the cows are milked, wood is cut 
and carried in, and everything put in shape for the night,— 
everything but the farmer himself—for he has not had time to 
rest, or to read the newspaper. Books he never sees, except 
their backs in the unused bookcases. Altogether he has 
worked,—have you ever counted it up and wondered how he 
stood it?—he has worked from twelve to fourteen hours. 
And yet we all know farmers who are still hard at work at 
seventy years of age. There must be something about farm 
life that keeps them up. There is, but why do they deprive 
themselves of all the joy of living? says the intelligent boy 
who has made up his mind to “clear out” for the city. 
After all, perhaps the farmers may work out the problem 
themselves. As a group of workers they can quit going 
without the happiness of life whenever they give thought to 
the reasons why they are obliged to work so hard, and get so 
little for it. CHAPTER XXVI 
OUR RESOURCES IN FOOD 
Grain Products.—The important grain products in this 
country are barley, buckwheat, corn, oats, rice, rye and 
wheat. Altogether they represent about one-half of the en- 
tire value of all our farm products. Of these grains corn is 
the most important in point of economic return, and barley 
is the least important. 
Barley is grown mostly in the North Central States and 
in California. As “pearled barley” it is used in soups. Bar- 
ley flour is dissolved and used as a food for babies in illness. 
Another use for barley is as a source of fermentable sugar. 
This is obtained by causing barley to sprout, in which con- 
dition an enzyme present in the grains changes starch to 
sugar. The fermenting sugar is called malt. Malt is modified 
to form various medicinal compounds, and in brewing certain 
alcoholic liquors. Barley grains are about the size of wheat 
grains. 
Buckwheat seeds are also about the size of wheat grains, 
but are three-angled in form. The blossoms are much fre- 
quented by honeybees. Fifteen to twenty million bushels 
are raised yearly, not a great quantity, but as a winter food 
buckwheat cakes are much prized. 
Indian Corn has been called King Corn because of its 
preeminence as a food, not altogether for man, but mainly 
for cattle and hogs. Corn is the most important single crop 
raised in the United States. As stated in Chapter XXI the 
chief value in corn lies in the fact that the grains are easily 
transformed into marketable pork and beef by way of the 
hogs and the cattle that eat the grain. Just as one will find 
297 298 
OUR RESOURCES IN FOOD 
Fig. 153. 
Stool of Buckwheat. 
Fig. 154. 
Stool of Rice. 
(Drawn by Maud H. Purdy.) GRAIN PRODUCTS 
299 
the iron and coal industries occupying the same territory for 
reasons of industrial convenience and economy, so the distri- 
bution of hogs and corn are almost identical, especially in 
regions where they exist in the greatest numbers. This is in 
Nebraska, Iowa, Illinois, Indiana and Ohio. From 85 to 90 
per cent of the corn crop is fed on the farms. 
The quantity of oats raised in the United States is about 
Fig. 155. Field of Rice in Texas. 
(© Keystone View Company, New York.) 
one-third the quantity of corn raised. It is a favorite food for 
horses whether in America or Europe. In America, at least, 
oatmeal is perhaps the most commonly used breakfast food. 
Incidentally, it contains all the nutrients (chemical classes 
of foods) present in other cereals, with a high percentage of 
oil. It is an interesting fact that we eat far more oatmeal 
in the winter time than we do in summer time. The body 
hunger adapts itself to using this cereal mostly in winter 
partly to use the oil as an added source of heat energy. 
Rice is being cultivated in considerable quantities in the 300 
OUR RESOURCES IN FOOD 
states of Louisiana and 
Texas. Perhaps about 
twenty-five million bush- 
els are produced in the 
United States. Rice is 
sold in two forms. One 
is the white “polished” 
rice that most persons are 
accustomed to seeing; the 
other is the brown or un- 
polished rice. The white 
rice in India, China and 
Japan, where it forms an 
important portion of the 
food of everyone, is now 
believed to be responsible 
for the prevalence of a dis- 
ease called beriberi (see p. 
348). The polishing of 
rice removes some impor- 
tant mineral and other 
compounds that are saved 
in the brown or natural 
rice. Moreover, the 
brown rice is thought by 
many to be more palata- 
ble anyway. Even so, the 
quantity of brown rice 
eaten is very small, so 
firmly fixed are some of 
our habits of selecting 
foods. 
About thirty million 
bushels of rye are pro- 
duced in the United States yearly. This is about one- 
Fig. 156. 
Stool of Oats. 
Fig. 157. 
Stool of Wheat. 
(Drawn by Maud H. Purdy.) GRAIN PRODUCTS 
301 
twentieth the quantity of wheat produced. About one-third 
of the rye produced is used to manufacture rye flour. The 
remainder is used as food for domestic animals. Rye bread 
is excellent, quite as good in every way as the best wheat 
bread. Probably the brownish color causes many persons to 
shun it. Children generally like rye bread, especially when 
the meaningless caraway seeds are not included. 
Wheat is the most important grain we have for bread- 
making purposes. It stands second to corn in the quantity 
produced, being nearly one billion bushels yearly, but stands 
first in the quantity actually sold and 
shipped away from the farms where it is 
grown. North Dakota, South Dakota, 
Nebraska, Kansas and Minnesota are the 
most important wheat-producing states. 
There is a great deal of discussion about 
the relative value of the different kinds of 
wheat bread. This is partly due to the fact 
that the white appearance of flour suggests 
that only starch is present. As a matter of 
fact, protein (the muscle, and other tissue- 
forming class of food compound) is distrib- 
uted throughout the mass of the wheat, 
although largest in quantity in the aleurone 
layer, just beneath the bran layer. 
The old fashioned method of grinding 
the wheat between the rapidly turning 
millstones made possible a classification of the product into 
white flour, “middlings” and bran. The white flour did con- 
tain less protein and less mineral substances than the mid- 
dlings. The middlings were considered inferior. This was 
sold for much less than was the white flour. The three classes 
of product were separated by the cylindrical sieve or “bolt” 
of silk of differing mesh. 
With the introduction of the system of crushing the wheat 
Fig. 158. Longitu- 
dinal Section op 
Wheat Grain. 
en, endosperm; cot, 
cotyledon; pi, 
plumule; r, radi- 
cle; era, embyro. 
(Drawn by Maud 
H. Purdy.) 302 
OUR RESOURCES IN FOOD 
by rollers, and the duplication of numerous systems of 
rollers for crushing and “granulating” the hard aleurone 
layer, it was possible to produce a flour, called “patent” 
flour, which gave the desired whiteness, and at the same time 
prevented the great waste incident to the manufacture of the 
old-fashioned “middlings.” Patent flour is bolted, and the 
bran separated from the remainder. 
Graham flour, unbolted, and entire wheat flour, bolted, 
Fig. 159. Reaping Oats. 
(Keystone View Company, New York.) 
owe their color to the presence of the particles of bran. To 
produce Graham flour and entire wheat flour is really less 
costly than to make patent flour, but owing possibly to the 
smaller demand and to the cost of advertising it, the bread 
from these two kinds of flour is more expensive than is white 
bread of good quality. As a matter of fact, however, the 
dark breads have a higher protein content as well as mineral 
content than are found in white bread. But experiments on VEGETABLES 
303 
the digestibility of breads show a much higher percentage for 
the white breads than for the dark breads. The lower per- 
centage of digestibility of the dark breads is probably due to 
the fact that the bran is digested with difficulty, or not at all. 
The meaning of all this is that there is little to choose between 
the white bread and the dark breads. Some persons like dark 
breads because of their effect on keeping the large intestine 
in active condition. But there are those who do not require 
this stimulus; others are affected unfavorably by it. 
Fig. 160. Threshing Wheat. 
(Press Illustrating Service, New York.) 
Vegetables. The term “vegetable” is a general one, and 
is not technically accurate. Under it are included seeds, 
such as beans and peas, fruits, such as tomatoes, leaves, like 
spinach, stems like asparagus, buds, like cabbage, bulbs, like 
onions, roots like carrots and sweet potatoes, anti tubers, 
like white potatoes. 
The quantity of these plant products is unknown, as also 
is the money value, but both are very great. The consump- 
tion of vegetables is undoubtedly increasing rapidly on ac- 
count of the understanding the people are gaining of the need Fig. 161. Some Descendants oe Brassica, the Wild Cliff Cabbage. 
A, wild cliff cabbage; B, broccoli; C, kale; D, kohlrabi; E, brussels sprouts; F, common cabbage; G, cauliflower. (From 
Gager: Fundamentals of Botany; P. Blakiston’s Son & Co., Philadelphia.) VEGETABLES 
305 
of vegetables in their bills of fare. New kinds of vegetables 
are created by experimenters in plant breeding. A good 
example of this is the near family kinship known to exist 
between kohlrabi, cauliflower, cabbage and Brussels sprouts, 
all having originated from an uncultivated plant somewhat 
resembling the cauliflower (Fig. 161). 
Another factor that will operate to increase the production 
and marketing of vegetables is the considerable profit the 
business insures. With the development of cold storage 
systems, and also with the extension of the alternation of 
cropping periods in the South and in the North, the enter- 
prise of supplying vegetables will become very important. 
Beans and peas are grown in enormous quantities as green 
vegetables in the whole pods, and as dried seeds. We pro- 
duce of the two annually about twenty-five million bushels 
as dried seeds. Both are also canned extensively. 
White potatoes give an enormous yield in this country. 
Perhaps five hundred million bushels are now produced each 
year. The yield is steadily increasing. Potatoes are so im- 
portant a food serving as a companion food for meat, that it 
may well be wondered how our ancestors got along without 
them before their discovery in America. The chief ingredient 
in the white potato is starch. Protein and fat and mineral 
products are present in very small quantities. 
Sweet potatoes are grown in relatively small quantities, 
being chiefly a product of the Southern States. They are 
similar to the white potato in composition except for having 
about eight per cent of sugar. 
Other vegetables are produced in undeterminable quan- 
tities. The quantities available for the table depend on the 
season, and also on the price, curious as the latter point may 
appear. After all we must remember that the reason we may 
have green vegetables when we want them is that some one 
finds it profitable to supply them. We pay for what is 
delivered, and at what is called the market price. If by any 306 
OUR RESOURCES IN FOOD 
chance the market price is very low, it does not mean that 
we shall be able to order freely for some time. The price may 
be so low that it does not profit the distributers to handle the 
product. Vegetables have been allowed to rot, or have 
actually been thrown into the sea to create a shortage, a 
condition that will cause the price to rise again. If the vege- 
tables can be put into cold storage, the effect on the price 
Fig. 162. Sweet Potato Plant. 
(Drawn by Maud H. Purdy.) 
will be the same. But whatever is done, the deeision depends 
on relative costs, and whether it pays. The two groups of 
persons who are liable to suffer from these phenomena of the 
market business are the producer who may be obliged to give 
hard service and lay out money, getting little or nothing ip 
return, and the “ultimate consumer,” the person who pays 
for the vegetables for his family. 
The business of food distribution is characterized by having 
a large number of “middle men,” some of whom perform very 
little service, taking meanwhile a little profit, passing the 
vegetables along for the next man in the line of “profiteers.” FRUITS AND NUTS 
307 
Fruits and Nuts. This subheading is somewhat misleading 
because nuts are practically all fruits. The fruits here in- 
dicated or implied are soft fruits. 
Every state in the Union contributes to the enormous 
total yield in value of fruits and nuts. North Dakota, 
Wyoming and Nevada yield the least, California the most. 
Fig. 163. Everbearing Strawberry Plant. 
(Keystone View Company, New York.) 
But N ew York, Michigan, Pennsylvania and Florida also 
yield tremendously. 
The classes of fruits recognized in the markets are small 
fruits, orchard fruits, grapes, citrus fruits, nuts, with peanuts 
in a separate class. The value and the yield of all these plant 
products are steadily increasing. Their value has now 
reached the total of hundreds of millions of dollars. Straw- 
berries represent about three-fourths of the total value of all 
the small fruits, followed in order of value by raspberries, 
blackberries, currants, gooseberries and cranberries. 
Orchard fruits are five times more valuable in the amount 308 
OUR RESOURCES IN FOOD 
yielded than are the small fruits. The apple, of course, is by 
far the most important orchard fruit. About two hundred 
million bushels of apples arc produced in the United States 
annually. 
Of the citrus fruits oranges are the most important in 
value. About twenty-five million boxes are produced yearly. 
Lemons come next in quantity. Grape fruit is being grown in 
increasingly larger quantity every year. But the cost is still 
Permitted to rot in California because their sale in East would not 
pay for freight charges. (© Keystone View Company, New York.) 
Fig. 164. Lemons Going to Waste. 
too great per fruit for families of moderate income. Indeed, 
the fruit itself is too large except for formal dinners. 
In the fruit-growing industry a portion of the problem of 
production and distribution has been worked out. The 
California Fruit-growers Exchange is a federation of co- 
operative associations of fruit-growers. These associations 
build packing-houses in which the fruit is brought together, 
graded, packed, and marked for shipment. The charge for 
this work is based on the number of crates each grower sends. SUGARS 
309 
The fruit trees are pruned and fumigated, and valuable 
information relative to the growth of fruit and to markets is 
supplied at the cost of the service. 
At one time about $1,000,000 worth of oranges and lemons 
were lost yearly by decay on the way from California to the 
Eastern markets. This has been eliminated by the introduc- 
tion of scientific methods of picking, handling and “precool- 
Fig. 165. Cutting Cane in Cuba. 
(Keystone View Company, New York.) 
ing” the fruit. Precooling consists in cooling the fruit at 
30° F. before shipping, loading in refrigerator cars, and 
shipping with a supply of ice to carry them to any part of the 
country. 
Sugars. There are several chemical compounds that go 
by the name of sugar. The principal one is called cane sugar, 
because it has come to be identified with cane as its chief 
source. It is also found in commercially valuable amounts in 
the sugar beet. In small quantities cane sugar or sucrose is 310 
OUR RESOURCES IN FOOD 
found in the fruits and stem juices of many plants mixed with 
glucose or fructose (fruit sugar). 
Cane is a plant that has been known to civilization from 
the earliest time of recorded history. In our territory it is 
grown in some of the Southern states, in Porto Rico, Hawaii, 
and in the Philippine Island. Cuba, however, is the country 
that produces the largest amount of sugar. 
Cane is produced by planting in furrows the tops of the 
stalks of the preceding year’s plants. Young plants sprout 
from these and grow one or two years before the stalks are 
ready to cut. When the crop is ready the stalks are cut close 
to the ground, stripped of the leaves and the green tops cut 
off. 
The sugar cane is hauled to the factory where it is passed 
through sets of corrugated crushers and rolls to crush free the 
juice of the stalks. From 11 to 1(5 per cent is waste fiber, 
used to burn and help operate the factory. 
The processes of evaporating the juice, crystallizing the 
sugar, refining or removing the molasses, filtering, evaporat- 
ing again, crystallizing again, are all involved with many 
intricate steps and minute attention to chemical and physical 
details. 
About three million tons of sugar are brought into the 
United States annually. Nearly all of it is refined here. We 
are able to produce only about one million tons in this 
country. 
Fats and Oils. Fats and oils are from both plant and 
animal sources. Butter comes from milk, oleomargarine and 
lard from meat fats, corn oil from the germ of the corn grain, 
olive oil from the olive fruit, cocoanut oil from the cocoanut, 
cottonseed oil from the seeds of the cotton plant. Of all these 
sources of fat, butter is not only the best known, but it is 
also by far the best for all purposes. 
Over one and one-half billion pounds of butter are made in FATS AND OILS 
311 
this country in one year. Until about the time of the Civil 
War butter making was entirely a household industry. Now 
nearly one-half the butter made in the United States is made 
at creameries. Dairy farmers may prefer to specialize in fur- 
nishing cream for creameries instead of making the butter 
themselves, or instead of shipping the milk to the head- 
quarters of the great milk distributing companies. Whether 
one or the other is done may depend on the situation of the 
farm. Farmers may use a cream separator for separating the 
cream from the remainder of the milk, and send the cream 
to the creamery. 
On a large scale butter is made by means of “combined 
churns” which churn the cream, gather the butter, wash it, 
salt it and “work” out the whey without exposing the butter 
to the touch of hands or to contact from flies. 
Butter keeps better in earthern jars, but on account of the 
great weight of such jars, tubs of spruce are commonly used 
except when butter is molded into “prints.” The tub butter 
is just as good, and costs retail about 5 per cent less. 
Butter contains on the average about 84 per cent of fat, 12 
per cent of water, over one per cent of curd, and about 2 per 
cent of salt and ash (minerals from the milk). Besides, it 
contains what is called a vitamin (see p. 350) an important 
substance not found in artificial butter. 
Oleomargarine is a name applied to a butter substitute that 
is made by churning beef fat with milk or cream to a butter- 
like emulsion. Legislation compels merchants to state the 
exact nature of butter substitutes, as well as to sell the butter 
color separate from the substitute. The amount of oleomar- 
garine sold is only about 2 per cent of the total value of the 
butter sold. When the superiority of butter is fully under- 
stood even less than 2 per cent may be expected as the sale 
of this substitute. Other butter substitutes are cottonseed 
oil, cocoanut fat and peanut oil. 
Olive oil is not used in the United States so extensively as 312 
OUR RESOURCES IN FOOD 
it is in certain European countries. We produce nearly a half 
million gallons, and import five million gallons yearly. The 
chief use of olive oil is as a dressing for salad. 
An important cooking fat is lard, the fat of hogs. We 
manufacture and export tremendous quantities of it. There 
are many substitutes for lard. These are mixtures of beef fat 
and cottonseed oil. Commercial forms of cottonseed oil are 
Fig. 166. Olive Trees in California. 
(Keystone View Company, New York.) 
hardened to resemble lard. Corn oil is a liquid fat that is 
becoming very popular as a cooking fat. 
Meats. The industry of meat packing is the greatest 
single manufacturing industry carried on in the United 
States. It exceeds by many millions of dollars annually the 
industries of foundry and machine shop products, and the 
lumber industry. And this estimate takes no account of the 
meat prepared for the market by local butchers or on farms. 
The center of the pork-packing industry is at Chicago, a MILK 
313 
fact that in part is determined by the nearness of the great 
corn fields of the middle West. At the same time it is the 
center for the distribution of most other meat products. 
Beef, pork and mutton are prepared at the establishments 
in Chicago, Kansas City, Omaha and other places with a high 
degree of efficiency and swiftness. The spoiling of meat is 
largely prevented by an elaborate system of chilling in cold 
storage rooms a few minutes after the animal is killed. When 
meat is to be kept a considerable time or sent a long distance 
it is thoroughly frozen. For example, we import frozen 
mutton from New Zealand, and export frozen beef to distant 
parts of the world. 
The federal meat inspection law of 1906 provides for the 
inspection of all packing houses, and all animals before and 
after slaughter. Carcasses that are found to be unfit for food 
are condemned. As condemned meat the carcasses may be 
transformed into fertilizer. 
Meats are the great sources of protein and fat. Meat food 
is prepared in every conceivable form as fresh meat, canned 
meat and dried meat. Meats are the most expensive forms 
in which the compounds occur anywhere, but a little meat 
appears to be necessary as a portion of human food. 
The net cost of lean meat is highest in the cuts that com- 
mand the highest price per pound. The cheaper cuts supply 
lean meat at one-half or less than one-half the cost of the 
expensive cuts. In reality the cheaper meat is as good as the 
more expensive kind. 
Milk. Attention has been called by scientific authorities 
to the fact that milk is the one article of diet the sole func- 
tion of which in nature is to serve as food. For the great 
class of mammals milk is the food which the mother animal 
provides for its young. Man is the only species which levies 
on other species for this food for his own use. We should note 
the fact, however, that through man’s attention to the selec- 314 
OUR RESOURCES IN FOOD 
lion of favorable variations in cattle there exist varieties of 
cattle to-day that produce far more milk than their own 
young require. 
It has been estimated that on the average each person in 
the United States consumes from one-half pint to one-third 
of a quart of milk a day. This may amount to as much as 
35,000,000 quarts a day for the entire country. At ten cents 
a quart, the daily bill for milk would be $3,500,000.00. et 
few are thoughtless enough to want to reduce that bill. 
The value of milk lies in its 
completeness as a food prod- 
uct. It contains a high per- 
centage of water, but fat, 
protein and milk sugar are 
present in about equal per- 
centages. In addition, there 
is the vitamin compound de- 
scribed on p. 350, without 
which the young of animals 
would never grow, no matter 
how much milk they might 
consume. 
A good milch cow will yield two gallons of milk per day 
for eight months of the year. Many high-grade cows produce 
six to eight gallons a day. By proper selection of varieties 
and by care and good feeding, the yield of milk is maintained. 
Under the best conditions cows are inspected for signs of 
disease. Stables are kept clean, and free from sources of 
possible contamination. All utensils employed in connection 
with handling the milk are kept clean by steam or boiling 
water. 
Milking is now done by mechanical milkers. These hasten 
the period necessary for milking and reduce the chances 
of the contamination of the milk. When they are not used 
the need of the personal cleanliness of the men in charge is 
Fig. 167. Mechanical Milker at 
Work. (Keystone View Company, 
New York.) EGGS 
315 
greater. Municipal inspection of the conditions under which 
milk is produced reaches out to the great dairy farms, and 
does effective work in protecting the lives of those in the city 
who consume the milk. 
The inspection of milk extends to lactometer tests, as well 
as temperature tests, by which adulterations may be de- 
tected and indications of the presence of large quantities of 
bacteria ascertained. 
Eggs. On account of the fact that most of the interior of 
the eggs of birds is a rich food substance set aside as nourish- 
ment for the young, it is natural for other species to find in 
eggs nourishment suitable for themselves. For that reason 
the eggs of birds are much preyed upon. 
It has been estimated that nine-tenths of all the farms 
in the United States keep chickens. The Eastern half of the 
country is bountifully supplied; the Western half more scant- 
ily supplied. 
In the months of March, April, May and June eggs are 
shipped in the largest quantities. In these months large quan- 
tities of eggs are placed in cold storage, to be sold later when 
the prices are higher. But when they are sold it is at a price 
several cents a dozen less than the current price for fresh 
eggs. 
Eggs are graded for the market according to freshness, 
size and color. Freshness is determined by “candling.” 
This is a term derived from the old fashioned practice of 
holding an egg up against the light of a candle. The test is 
more effectively made by placing the egg in an aperture 
beneath which is an electric light bulb. A fresh egg shows a 
small air space at the round end. An old egg shows the air 
space much enlarged. If there are “ spots” or fungus growths, 
these are also shown by the candling test. 
When eggs are cheap some persons immerse large quan- 
tities in jars containing water glass (sodium silicate). The 316 
OUR RESOURCES IN FOOD 
chemical seals the pores of the eggshells, and thus prevents 
the entrance of bacteria or the spores of fungi. These eggs 
cannot be boiled, however, without breaking, on account of 
the closed volume of air within the egg. Besides, it is some 
1, 2, 3, quite fresh; 4, 5, 6, showing gradual shrinking of egg contents, 
leaving air space above; 7 to 12, interior molds growing in egg con- 
tents; 8, a broken egg, with mold growing beyond shell. (Keystone 
View Company, New York.) 
Fig. 168. Fresh Eggs and Stale Eggs. 
trouble to prepare the solution and to store away the eggs. 
Most persons content themselves with paying the higher 
price asked for fresh eggs. CHAPTER XXVII 
OUR RESOURCES IN CLOTHING 
The first great need of human beings is for food. The 
second is for clothing. There are four chief sources of the 
materials that go into the creation of articles of protection 
and comfort for our bodies. These are cotton, linen, silk and 
wool. Articles made of fur are also in use, even more than 
linen is, at least in the United States, but fur is now a luxury, 
and unnecessary, as indicated in Chapter XIII. True, our 
primitive ancestors did use skins of fur for garments as do 
the people of the far North to-day, because they could and 
can get nothing else. It may be granted that fur garments 
are useful for anyone who is subjected to such low degrees of 
temperature as are characteristic of the polar region. 
It is interesting to note the fact that just as skins were 
used by the people who could get that kind of clothing better 
than any other, the same is true of the primitive use of the 
fibers of plants, of the hair of some animals, and of the thread- 
like product of others. The production and use of all four 
of the common materials from which articles of clothing are 
made to-day had their origin in those sections of the world 
where the plants and animals yielding the raw substances 
were easily available. The portions of the world in which 
this occurred were on the continent of Asia and in the warm 
and temperate regions of that continent. Cotton, linen, silk 
and wrool have been traced as materials for clothing into re- 
mote antiquity. 
The Egyptians used all these materials as did other national 
groups of human beings in central and eastern Asia. But 
where the manufacture of each began we can no more say 
317 318 
OUR RESOURCES IN CLOTHING 
with certainty than we can say wThere civilization itself began. 
However, central Asia was in all probability the “cradle of 
the human race.” Within the same region there would 
naturally be the longest period of human experience. In the 
presence of the plants and animals that yielded the rawr 
materials for clothing through that long experience there 
would tend to be developed first the primitive notion that 
fibers and hairs could be arranged in the form of primitive 
weaving. By the slow' process of “trial and error” through 
thousands of years, we have reached a stage of development 
where the production of articles of human wear and comfort 
are carried on in gigantic industries. The conduct of these 
industries in this country gives employment to hundreds of 
thousands of men and wromen and involves the use of many 
billions of dollars of capital. In fact, the annual product of 
the mills themselves yearly is worth billions of dollars. 
Cotton is made from the plant hairs or fibers that surround 
the seeds in the pod or fruit of the plant. Although most of 
the cotton fibers are over an inch in length, sometimes nearly 
two inches, fibers can be spun into yarn even when the fibers 
are no more than three-fourths of an inch in length. 
The cotton plant is widely distributed throughout the 
world north and south of the Equator to the 35th degree of 
latitude. Cotton grows in all our southern states except 
Kentucky. The production of cotton is the chief agricul- 
tural interest of these states. 
In the United States the cotton plant, Gossypium hirsutum 
is an annual plant. The seeds are planted from March to 
May. The plants grow to a height of four to six feet. The 
flower has five large whitish or yellowish petals. The blossom 
is open but one day. The petals then fall off. The base of 
the pistil gradually enlarges into a three-celled or five-celled 
pod. When the pod has grown to the size of about one inch 
COTTON OUR RESOURCES IN CLOTHING 
319 
in diameter, and has ripened, it bursts open and discloses the 
large mass of cotton fibers surrounding in mat-like masses the 
several seeds. The pod is called the “boll.” The boll 
matures from August first to late November, depending on 
the latitude. 
As soon as the bolls are open the cotton must be picked. 
The men, women and children who pick the cotton work 
long hours to gather the crop to prevent waste. Picking the 
Fig. 169. Cotton Field. 
(Keystone View Company, New York.) 
mass of cotton out of the open boll and leaving the husks of 
the bolls behind, an average adult picker can gather 200 to 
250 pounds of seed cotton in a day. The pickers toss the 
handfuls of cotton into a bag which is slung over the shoulder. 
When the bags are full the contents are collected by wagons 
and taken to the cotton gin. 
The school histories tell of the great importance of the 
invention of the cotton gin, and give the name of the inventor 
and the date, Eli Whitney, 1793. Whitney was a Northern 
man, a teacher in a cotton district in the south. He had 
noticed the slow, tedious process by which the cotton fibers 320 
OUR RESOURCES IN CLOTHING 
were pulled away from the seeds. His cotton gin consisted of 
a cylinder or drum on the surface of which were hooks or 
teeth. The drum was made to 
rotate against a grate. The seed 
cotton was caught up by the teeth 
and came into contact with the 
grate. The cotton fibers were 
pulled away from the seeds, and 
the fibers later in the turn of the 
drum were removed by an auto- 
matic brush. Before Whitney’s 
time a man could separate the 
seeds from only one pound of cot- 
ton a day. The latest improvement of the cotton gin can 
clean four thousand pounds a day. No wonder the invention 
Fig. 170. Cotton Fibers on 
the Seed. (Drawn by Maud 
H. Purdy.) 
Fig. 171. Modern Cotton Gin. 
(Keystone View Company, New York.) 
of the cotton gin was recognized as one of the most important 
inventions of modern times. An expensive fiber was made 
the cheapest of all fibers for clothing. OUR RESOURCES IN CLOTHING 
321 
When the cotton is ginned it is packed under hydraulic 
power and bound with jute bagging and with steel bands 
for shipping. Such a mass is called a bale. There are about 
500 lbs. in a bale of cotton in the United States. Each cotton- 
producing country has its own way of baling cotton. Ours is 
said to be the worst, because it is the most wasteful. 
We ship baled cotton to our Northern cotton mills in the 
states of Massachusetts, Rhode Island and Pennsylvania. 
We ship also to Great Britain and to other European coun- 
tries. Great Britain owns nearly half the entire cotton 
manufacturing mills in the world. For this reason it is not 
surprising that we import from Great Britain large quantities 
of cotton cloth and cotton yarn, undoubtedly some of it 
made from the raw cotton we had sent to Great Britain. 
The manufacture of cotton cloth is of itself a tremendous 
industry. The mere names of the machines employed in the 
work make a long list. The processes of manufacture are 
bewildering in their complexity. As in all modern industry, 
the tendency is for the workers to be doing small tasks in the 
factory that would employ thousands of men and women. 
LINEN 
If some process had been discovered by which linen could 
be produced at a cost nearly as low as we produce cotton, 
linen would be much more commonly used as an article of 
wear than it is to-day in this country7. But at one time linen 
was more common than it is to-day. We used to have sheets, 
pillow cases, towels and handkerchiefs made of linen. Men’s 
suits and “dusters” and women’s dresses made of linen were 
common. To-day linen is very little worn in this country as 
clothing. But it still holds supremacy as table linen, and in 
laces. Curiously enough the Russian peasants still wear 
linen underwear for winter use. 
The relative cheapness of cotton goods, together with the 
numerous processes that have been discovered for making 322 
OUR RESOURCES IN CLOTHING 
cotton goods look attractive, have doubtless had some in- 
fluence in causing the consumers to cease wanting linen. 
Those who wanted and could purchase more expensive rai- 
ment than that made of cotton were probably attracted to the 
numerous and new processes by which silk is made beautiful 
for garments. No doubt that also the processes by which 
wool was turned into very delicate materials served as 
factors in the evolution of dress by which linen has expe- 
rienced practical elimination in the “struggle for existence.” 
The tariff on importations of linen has also affected the 
situation. We still have our linen closets in the houses, but 
there are usually cotton sheets, cotton pillow cases and cotton 
towTels on the shelves. However, France, Germany, Belgium 
and especially Great Britain continue the manufacture of 
linen for a great many uses. The entire annual output of 
linen fabrics for the world is over one billion pounds. 
Linen is made from the fibers of the bark of the flax plant, 
Linum usitatissimum. The flax plant is annual, and grows 
from twenty to forty inches high. The small flowers range 
from yellowish to bright blue in color. The seeds are small, 
brown and flat. The chief product of flax plants in this 
country now is the seeds. The seeds are ground and the oil 
is pressed out. This is the familiar linseed oil used in paints. 
In the preparation of the flax plant for the manufacture of 
linen the plant is pulled up by the roots to prevent the escape 
of certain plant juices necessary to the satisfactory ripening 
of the fibers. Later the roots are cut off and the tops removed. 
In Belgium where the best linen is made, floats are prepared 
and large quantities of flax stems are laid out and covered 
with weights so as to sink the flax several inches beneath the 
surface of the water. In that position bacteria attack the 
soft tissues in the bark of the flax causing decay. The bast 
fibers from which linen is manufactured are loosened, and 
later can be freed entirely from other tissue. This process is 
called retting. OUR RESOURCES IN CLOTHING 
323 
The stems are then removed from the water, dried and 
passed through numerous processes of separation and carding 
or arranging in parallel rows for spinning. The weaving, 
finishing, bleaching and dressing of the linen require elaborate 
machinery and highly skilled workers. 
WOOL 
In all the world there are about 700,000,000 sheep. In 
the United States there are about 40,000,000. The United 
Fig. 172. Sheep Shearing Scene. 
Mechanical shearers at work. 
(Keystone View Company, New York.) 
States stands second to the United Kingdom in the amount 
of wool consumed in manufacture. This country produces 
about two-thirds of the amount of wool it consumes in manu- 
facture. 324 
OUR RESOURCES IN CLOTHING 
It is well known that sheep require a great deal of care to 
yield the most satisfactory results. The slightest neglect 
of the welfare of the sheep gives rise to one or another defect 
in the wool fibers themselves. 
The great wool-producing states of the Union are in the far 
West. These are Idaho, Wyoming, Montana, Utah, Nevada, 
Washington and Oregon. Each of these states contains over 
4,000,000 sheep. There are occasional sheep ranches where 
as many as 100,000 sheep are owned by one company, or even 
by one man. With so many, it is impossible to give detailed 
care and large numbers of sheep are lost in the winter storms, 
or the wool is injured by extremes of weather conditions, or 
lack of proper feeding. 
Sheep are brought to the shearing pens at the beginning of 
the warm season. The shearing is carried on by using the 
hand shears, or machine shears. A sheep is thrown on its 
haunches and held between the legs of the shearer. These 
animals are docile and stupid creatures. They will remain 
still in that position, their legs hanging helplessly out in front 
while the operator trims the mat of wool in a single piece 
from their backs, sides and legs. The entire cutting is called 
the fleece. After the wool is removed, the sheep is thrown 
into a vat of antiseptic solution to destroy parasites and 
disease. The fleeces are packed into a long bag and prepared 
for shipping to the market. Boston, New York and Phila- 
delphia are the chief markets for the sale of raw wool. 
When the wool comes to the mills, the bags are opened, 
and the sorting begins. This selection of fleeces of varying 
grades is carried on under conditions of some danger to the 
workers, because of occasional contact with “wool sorters’ 
disease,” or anthrax. Sheep are filthy animals, and the 
fleeces require extensive cleaning. Dirt must be removed, 
grease must be eliminated, burrs must be separated from the 
fleeces. 
When the cleaning is finished, the wool must be carded or OUR RESOURCES IN CLOTHING 
325 
laid in parallel lines for spinning. The weaving of wool 
into cloth has been developed into an art. The number of 
combinations possible by the selection of yarn, by the assem- 
bling of shades after dyeing and by the character of the weave 
itself are apparently unlimited. And after the cloth is woven 
A, silkworm in fifth period, full size; B, moth; C, pupa; D, eggs of 
moth; E, diagram showing cocoon and method of winding. (From 
Matthew: Textile Fibers; John Wiley & Sons.) 
Fig. 173. Life-History of the Silkworm. 
there are numerous processes of finishing which give the cloth 
quite different appearances. 
There are about fifty distinct and well-known types of 
wool and worsted materials that result from differences in the 
fiber, differences in the preparation of the fibers, and differ- 
ences in weaving and finishing. The machinery, like that of 326 
OUR RESOURCES IN CLOTHING 
other weaving industries, is complicated and expensive. 
There are very many small tasks each one of which a man or a 
woman sticks to for years on end. But it has been said that 
Fig. 174. Silkworm Caterpillars Feeding on Mulberry 
Leaves. Japan. (© Keystone View Company, New York.) 
the manufacture of wool requires more intelligence than do 
other industries. 
SILK 
Silk is the most beautiful of all textiles. It is likewise the 
most expensive. Like the other textiles described in this 
chapter, the beginning of its manufacture is lost in antiquity. 
The source of the fiber from which silk is made is the OUR RESOURCES IN CLOTHING 
327 
cocoon of the cultivated silkworm, Bombyx mori. This 
silkworm passes through four changes in two months. These 
stages are egg, larva, pupa and adult. When the adults emerge 
mating takes place. After the female lays several hundred 
eggs, and within three days after her emergence from the 
cocoon, she dies. 
When the eggs hatch the young caterpillars begin to feed 
on chopped mulberry leaves. After the larva has shed its 
skin four times it is full size, about three inches in length. 
The larva then soon begins to show signs of wanting to climb 
and spin its cocoon. The two glands behind the mouth begin 
to secrete their fluid which on exposure to the air hardens into 
a double thread. In three days the larva has completed its 
cocoon, and has spun out from 1,000 to 4,000 feet of silk, seal- 
ing the w hole w ith a gummy substance. 
The first step in the care of the silk from the cocoon is to 
place a number of them in boiling water to destroy the life 
of the pupa, and to dissolve the gum holding the fibers to- 
gether. A number of ends of the cocoon threads are placed 
together and then “reeled” in preparation for spinning. 
Before spinning all the gum and the color must be removed. 
Degumming leaves the silk very light. To make up the 
loss in weight the custom of weighting the silk has developed. 
The silk is immersed in a series of solutions, and is charged 
heavily with crystallized tin and other metals. The tin or 
other metal gives desirable weight, but its presence cuts the 
silk fiber. Burn a piece of weighted silk, and the mould of 
the piece is left in metal. Weaving and finishing give the 
opportunity to produce the numerous and elaborate kinds of 
silk. 
The principal silk manufacturing countries are France, 
England, Germany, Switzerland, Italy and the United States. 
Japan and China lead in the Far East. CHAPTER XXVIII 
OUR BODIES AS WE FIND THEM; AND THE FOODS 
THEY NEED 
(A Preliminary Study) 
Living and Working. Here we are upon the surface of 
the earth of different ages, and different mental and physi- 
cal characteristics. People have lived here before us and 
others will live here after us, perhaps eternally. The fact 
of living carries with it the evident fact that we are doing 
something. Whether we are lying on the grass looking at 
the clouds floating over the trees, or whether we are making 
the wheels of industry and commerce go round and round, 
our own body-machines are keeping up incessant activity. 
There are some persons who are said to work only when 
they eat. However, after the hands finish their task of con- 
veying food to the mouth, and the jaws are through with 
chewing, their owners may lie on the grass if they like, but 
their body-machines have only begun to work. The resting 
stomach feels the thrill of the message carried down by the 
nerves, and at once begins its steady, continuous operations. 
Later the intestine takes up the task, and when the food is 
digested, the blood catches it up and whirls it away under 
the pressure of the great muscular, nerve-controlled heart. 
A Wonderful Industry. Although the story as we give 
it thus is quickly told, we have only made a beginning on 
the most wonderful industry the world has ever known,—the 
industry involved in a living body doing its work. The food 
is carried along in the great highways,—the blood vessels— 
and dropped off where transforming stations are in operation. 
328 A WONDERFUL INDUSTRY 
329 
Fig. 175. Circulatory System with the Out- 
line of Other Internal Organs. (From 
Hough & Sedgwick: The Human Mechanism; 
Ginn and Company.) 330 
OUR BODIES AND THE FOODS THEY NEED 
The first of these is the liver (Fig. 175). This is one of the 
greatest in size, and one of the most important parts of the 
machinery. It has taken scientists a long time to find out 
what really happens there, but now we know. Next, the 
transformed food travels again on the highways to every 
station, great and small, upon the system. That means 
that every one of the millions of cells in the tissues of the 
body is reached in a short time by a portion of the food 
which the resting hand, jaws and teeth have brought in. 
In these cells complicated chemical changes take place by 
one of which the food becomes part of the body, by another 
it is stored for future use, and by still another fit is burned 
up, consumed, and thus employed to yield the heat which 
the whole machine requires to keep it in working order, 
or to yield the energy of motion which the organs manifest. 
Back on the system somewhere at a station called Lungs 
(Fig. 175) a light material, Oxygen by name, was taken into 
the blood and became part of the load which the blood car- 
ried along. The complicated changes in the cells just re- 
ferred to could not have taken place without the oxygen. 
It is by the union of the oxygen with the carbon in the food 
that the heat and the motion are produced. 
Back again by another branch to the lungs comes the 
material that was made in the cells through the chemical 
process by which oxygen and carbon was combined. This 
material is waste. It is that well-known gas, carbon dioxide. 
Certain kinds of products made in the cells, however, 
must go back again to the liver to undergo another change. 
They are shifted by a new route to the kidneys (Fig. 175), 
and there are blood vessels and blood to carry them thither. 
In the kidneys these wastes are taken out, and the blood 
freed from these substances travels back to go round and 
round on its never-ending journey. 
It does not take a very active mind to see that if a person 
is averse to work of any kind, all he needs to do is to stop THE NUTRIENTS 
331 
eating. In a short time his body machine will begin to run 
down, and soon it will actually stop. It is therefore a very 
fundamental need wdiich is connected with this habit of 
using food. It is not only fundamental for us human beings, 
but also for all animals as well as for all plants. 
Our Primal Need. In studying our bodies as we find 
them, and possibly trying to improve them, it is both natural 
and easy to begin with the food wre eat, learning the real 
nature of what we eat, why we eat particular kinds, and 
what happens to food when it is eaten. 
As we have already learned in Chapter XV, our remote 
ancestors probably ate the soft fruits and the hard nuts of 
the forest, the roots of plants, and the flesh of animals. 
We eat the same things to-day, but we have them in greater 
variety, more elaborately prepared, served and partaken 
of with more of the deliberation known as “table manners.” 
But with all our great variety, there are certain foods which 
are staple for us in America, that are eaten by the people 
of all nations. Chief among these are the meat of cattle, 
sheep, pigs, and fowls, eggs, milk, butter, cheese, bread and 
other cereal products, potatoes and other vegetables pro- 
ducing quantities of starch; and there are beans, cabbage, 
sugar, soft fruits and nuts, water, and salt. 
The Nutrients. The chemists have shown us what 
there is in these foods that is identical, why substitutions 
of one for another may be made, and why it is necessary 
for us to eat the particular chemical material found in the 
foods. The chemical analysis of every food in common use 
has been made, and it is known that the thousands of foods 
are in reality combinations of relatively few kinds of mate- 
rials. These few kinds are called nutrients; and they are 
severally called the proteins, the carbohydrates, the fats, 
the inorganic salts, the vitamins, and water. 332 
OUR BODIES AND THE FOODS THEY NEED 
Typical proteins are the white of egg, the lean of meat, 
the curd of milk, and the sticky gluten of wheat to be ob- 
served in dough. It is also present in many other foods, 
usually in unnoticed combination with other nutrients. 
Examples of these cases are beans, peas, and all cereals. 
Although the nutrient protein, as the white of egg, is a 
distinct material, the chemical analysis shows that the 
elements present are carbon, hydrogen, nitrogen, oxygen, 
and sulphur. Some 
proteins contain also 
phosphorus and iron. 
The carbohydrates 
include all kinds of 
sugar, chief among 
which are cane sugar, 
glucose, milk sugar, 
maltose, and fruit sug- 
ar. Starch also belongs 
to the carbohydrates. 
Starch is present in 
corn, wheat, and all 
cereals, in potatoes 
and other vegetables. 
Chemically this nutri- 
ent differs from the proteins in being composed only of car- 
bon, hydrogen, and oxygen. The term carbohydrate is made 
up from the word carbon and the word hydrate. Hydrate is 
a chemical term applied to combinations of hydrogen and 
oxygen that are proportional to the number of hydrogen and 
oxygen atoms in water; that is, two atoms of hydrogen and 
one of oxygen. The chemical symbol for water is H20. The 
hydrogen and the oxygen exist in that relative number in all 
carbohydrates. Glucose is as simple as any carbohydrate; 
its chemical formula is C6Hi206. 
Fat is a term that requires little explanation. Familiar 
Fig. 176. Foods Representing Nutrients. 
Protein, by white of egg and lean of meat; 
starch, by potato and tapioca; sugar, by 
cane sugar; fat, by butter and olive oil. THE NUTRIENTS 
333 
fats are butter, lard, olive oil, and the fat of meat. Fat or 
oil is present in small or large quantities in nuts, a limited 
quantity in cereals, and scarcely at all in soft fruits. The 
elements are the same as in carbohydrates, but the relative 
number of each is quite different. A molecule of fat contains 
many atoms of carbon and many of hydrogen, but few of 
oxygen. This fact is of great importance in the disposal 
COMPOSITION OF SOME COMMON FOODS 
From Hough & Sedgwick’s Human Mechanism 
Food 
Water 
Proteid 
Starch 
Sugar 
Fat 
Salts 
Bread 
37 
8 
47 
3 
1 
2 
Wheat flour 
15 
11 
66 
4.2 
2 
1.7 
Oatmeal 
15 
12.6 
58 
5.4 
5.6 
3 
Rice 
13 
6 
79 
0.4 
0.7 
0.5 
Peas 
15 
23 
55 
2 
2 
2 
Potatoes 
75 
2 
18 
3 
0.2 
0.7 
Milk 
86 
4 
5 
4 
0.8 
Cheese 
37 
33 
24 
5 
Lean beef 
72 
19 
3 
1 
Fat beef 
51 
14 
29 
1 
Mutton 
72 
18 
5 
1 
Veal 
63 
16 
16 
1 
Whitefish 
78 
18 
3 
1 
Salmon 
77 
16 
5.5 
1.5 
Egg 
74 
14 
10.5 
1.5 
Butter 
15 
83 
3 
of fats when we eat them. A molecule, you should under- 
stand, is the physical unit of a substance, either of an ele- 
ment or a compound. An atom is the smallest particle of 
an element. A molecule of water, the smallest physical 
division, is made up of two atoms of hydrogen and one atom 
of oxygen. In a mass of oxygen or of hydrogen, or other 
element, the atoms aggregate themselves naturally into the 
smallest physical division, that is, into molecules. 334 
OUR BODIES AND TIIE EOODS THEY NEED 
The inorganic salts are mineral combinations usually 
found with other nutrients. They are salts in which sodium, 
phosphorus, potassium, magnesium, and iron are found. 
Water also is inorganic, that is, not made by a living thing, 
and as everyone knows is absolutely necessary to life. 
These nutrients occur in certain definite percentages in 
our common foods. Tables of percentages have been pre- 
pared to show the composition of the foods. In the foods 
selected for this table it will be noticed that the animal foods 
do not have starch and sugar, but that plant foods have all 
the kinds of nutrients. 
A casual inspection of the table will give you some 
information on a very important question; that is, the ques- 
tion of why we eat certain kinds of food. By that we mean 
more exactly why we eat certain nutrients. All kinds of 
flesh in the list you will see contain water, protein, fat, and 
salts. Human flesh is known to be like the flesh of other 
animals in this respect, and also to be like them in not con- 
taining starch and sugar. At the same time, all the foods 
from plant sources not only contain the nutrients men- 
tioned, but sugar and starch also. 
Growing and Repairing. You have been growing larger 
every year for twelve, thirteen, fourteen, fifteen or more years. 
It is obvious that your added weight every time you stand 
upon the scales and test the matter, must come from some- 
thing outside yourself. Nothing could be more natural than 
that the added weight should come from the same kind of 
substance which it now is. This is a fact with very slight 
exception. 
But it is important to know that your body as it exists 
at any moment you may happen to weigh it does not tell 
you its whole story of change. While you work, or play, or 
sleep, the protein in the protoplasm or living cell substance 
of your body is used up to a slight extent continuously. The THE HUMAN MACHINE 
335 
protoplasm thus consumed must be replaced, and with ma- 
terial similar to it, that is, with protein. Some of the pro- 
tein which an adult person eats goes into this repair work. 
The remainder of it is used as sugar and starch are used. Nor- 
mally the adult does not grow, as you do. That is one rea- 
son why a young person, even a child, frequently eats much 
more than his size would appear to warrant. 
In a similar way, a child wants sugar and candy more than 
do grown persons. With our better understanding of the 
physiology of foods, adults are less inclined than they used to 
be to think that the desire for sugar on the part of children 
is a sign of natural depravity. As a matter of fact, they need 
it more than adults do. Why does anyone need sugar? 
Let us see. 
The Human Machine. In the preliminary account of 
the working of the body you will remember that a great tleal 
was said about the fact of working. Every organ is doing 
something. This is very much what is taking place in any 
machine, whether it is a reaper, a threshing machine, an en- 
gine, a dynamo, or a sewing machine. The parts do not work 
of themselves, and we must try to determine what it is that 
makes them go. In the case of the reaper, it is evident that 
the horses do the work. It may be so with the threshing ma- 
chine, or the machine may be operated by the power sup- 
plied by an engine. We know of course that the power of the 
engine is derived from the burning of coal or wood, and that 
the heat thus developed changes water into steam, which in 
turn by expanding sets the piston rod, and finally the wheel 
and the belt, into operation. The initial impulse to the work 
came from the burning of something. As we already know, 
burning is a chemical process in which oxygen from the air 
unites with carbon, producing carbon dioxide incidentally, 
and releasing a supply of energy in the form of heat. By sim- 
ple transformation the heat may become mechanical energy. 336 
OUR BODIES AND THE FOODS THEY NEED 
Oxidation and Energy. If anyone is curious to know 
whether some of our foods will burn and yield energy as coal 
and wood do, let him throw into the stove fire a piece of 
bread, a lump of sugar, or a strip of bacon. In some parts 
of the West in seasons when corn is plentiful and cheap it 
was sometimes formerly used for burning in the place of coal 
or wood. Granaries of wheat also sometimes take fire and are 
burned up. But let no one think that a flame might be seen 
burning brightly inside his own body after a hearty meal of 
bread and butter and jam. When foods that will burn in 
the air are eaten and digested and carried where they come 
into contact with the oxygen that enters by way of the lungs, 
the carbon of the food unites with the oxygen without a 
flame, slowly and at a temperature lower than the tempera- 
ture at which the food woidd unite with oxygen in the air. 
This process by which oxygen and carbon or any other ele- 
ment unite anywhere is called oxidation. If you use that 
term you may cease to think that flaming is a necessary 
characteristic of this chemical change. 
It so happens that the starches, the sugars, and the fats 
have molecules with carbon atoms in larger number than 
are necessary to hold the oxygen the molecules already have. 
This is especially true of fats. Each carbon atom will unite 
with two atoms of oxygen, and in a common fat molecule 
there are fifty-one carbon atoms and but six oxygen atoms. 
Thus the carbon in each molecule could unite with one hun- 
dred two oxygen atoms. The hydrogen atoms present add 
to themselves a great number of oxygen atoms. Between the 
carbon and the hydrogen an enormous amount of heat may 
be developed when persons consume fat. The reason that the 
Esquimaux are so partial to whale, seal, or walrus fat is evi- 
dent. Arctic explorers imitate the natives, because they must 
do so, in order to make up for the great radiation of heat 
from their bodies in the cold climate. 
If an Arctic explorer is lost from his base of supplies and OXIDATION AND ENERGY 
337 
cannot obtain any kind of food, his supply of energy would 
then have to come from his own stored-up fat. But all the 
time he would lose about four ounces of protein daily from 
his own body through “wear and tear.” When his supply 
of hotly fat is gone, the energy required for the work his or- 
gans do would be obtained by the oxidation of some of his 
own protein or flesh. He would then lose weight still more 
rapidly. In health and plenty the carbohydrates and the 
fats we eat are oxidized, and the protein of our flesh is saved 
from what takes place in the body of a starving man. For 
that reason, carbohydrates and fats are sometimes called 
“protein sparing” or “protein protecting” foods. 
Then, adolescents and grown-ups eat starch, sugar, fat, 
and some protein for the energy they yield. The remainder 
of the protein is available for repair. If they play hard, 
work hard, or grow rapidly, or live in a cold climate, they 
need more of these foods than the same persons would need 
under the opposite conditions. CHAPTER XXIX 
THE SOURCES OF OUR FOOD SUPPLY 
Natural Foods. Milk has been called a natural food, 
because man and other members of the highest class of ani- 
mals get it naturally without preparation or modification. 
Milk is also called a complete food, because it contains all 
the nutrients that are necessary for growth, for repair, and 
for the supply of energy. These, as we remember, are pro- 
teins, sugar, fats, salts, and water. Although we drink milk 
for a longer period than does any other mammal, we require 
later the addition of other nutrients. These additional 
foods that we begin to use early, we become accustomed to 
by the time we are three or four years of age. 
Among the early foods given to young children are certain 
cereals. In one form or another, cereals are eaten by per- 
sons of all ages in all countries. By cereals of course we 
understand not only prepared grain products like oatmeal, 
but all kinds of bread made from grains. In a certain sense 
cereals are also natural foods. Reference to the table given 
in Chapter XVII will show that they contain all the nutri- 
ents, and supply all the needs of human beings. Not only 
that, but they also supply the needs of plants as well. The 
meaning of this is that all cereals are derived from seeds, or 
more accurately from grains. A grain of corn is a fruit pro- 
duced by a corn plant, which may be regarded as a mother 
plant. The grain contains the young plant of a new genera- 
tion; this young plant is called the embryo. It is surrounded 
in the grain with extremely rich food material which is to be 
used by the embryo in beginning its life, and in forming the 
organs of the little corn plant. Chemical analysis shows that 
all the nutrients are present. 
338 NATURAL FOODS 
339 
Since you have followed the development of seeds, yoi 
know that the material of the seeds is used up in forming 
the stem, leaves, and roots of the young plants. Having 
formed these organs, the plant must go on and grow large] 
by using the materials it obtains from the air and the soil 
Our levies upon the seeds, nuts, and other fruits in our fooc 
supply is enormous. And you realize that we take these 
materials because they contain the nutrients which oui 
bodies require. Since the plants need them, too, in a certair 
stage of their existence, 
we learn the lesson of one 
important resemblance 
between ourselves and 
plants. 
At the same time, it is 
worth while to call atten- 
tion to the fact that a 
plant well started on its 
career must later produce 
for its seeds, as well as for 
its own growth, a new sup- 
ply of nutrients. The fact 
that important nutrients, 
proteins and carbohy- 
drates, are made from certain raw materials, carbon dioxide 
and water only by plants should impress upon us our abso- 
lute dependence upon plants for our existence. If you think 
we could get proteins from meat, you should trace the his- 
tory of that protein through the animals whose bodies have 
contained it. How many steps is it till you come to plants? 
Before we have attained the age of three we have par- 
taken of another natural food—eggs. Eggs stand in the same 
relation to their producers that seeds do. A mother-being 
made them and surrounded a germ of the young animal 
with nutrient of the needed kind. As has been stated al- 
Fig. 177. Group of Natural Foods. 
Milk, oat meal, orange, egg, meat, 
honey, corn, hominy, apple. 340 
THE SOURCES OF OUR FOOD SUPPLY 
ready, the white of egg is protein. The yolk contains oil, 
and also protein, as well as several inorganic nutrients, iron, 
phosphorus, lime, etc. Directly out of this store of nutrients 
comes the body of the young fowl, feathers, flesh, bones, 
nerves and all. The germ is chiefly a microscopic group of 
cells in which reside the life and the power of beginning the 
process of growth. The actual substance of the fowl comes 
from the nutrients which are used under the control of the 
germ. We eat eggs for the protein, the oil, and the minerals, 
and they make valuable food. 
One very interesting and characteristic fact about nature 
is the ease with which knowledge of it may be classified and 
arranged in a comprehensive system. This is what makes 
it possible to have sciences. They are knowledge classified 
and brought into systems, the parts of which are related to 
one another. For example, our foods are either from living 
sources or from non-living sources; that is to say, they are 
organic or inorganic. The organic foods are either from 
plant or from animal sources. Practically all plants that 
are used by human beings for food develop from seeds. As we 
have seen, in some cases we consume the seeds, and in others, 
a portion of the plant; in still other cases, we eat both seeds 
and a portion of the plant. Our food from animal sources 
is either the egg, a portion of the animal’s body which is de- 
rived from the egg, or it may be a product of the animal, as 
for example, milk, butter, cheese, or honey. The inorganic 
foods, the salts and the water, come into existence indepen- 
dent of any living thing, but they may be present at a given 
time in some animal or plant body; in fact, the inorganic 
materials in which we are especially interested are required 
in our living body, just as much as are proteins and carbo- 
hydrates. 
It will be worth while at this point to state more fully the 
sources of the nutrients. For this purpose the carbohydrates 
will be divided into sugars and starch. SUGARS 
341 
Sugars. The sugars that most persons eat in one form or 
another are glucose, cane sugar or beet sugar (saccharose), 
and maple sugar. Glucose is produced artificially by remov- 
ing the starch from corn grains, or from potatoes, and treat- 
ing it with dilute hydrochloric acid. 
According to the method of preparation, we may obtain 
solid lumps of glucose, or a liquid. Glucose may be obtained 
Fig. 178. Collecting Maple Sap. 
(Courtesy of American Museum of Natural History.) 
from natural sources by the preparation of the juice of 
corn, and it occurs in maple syrup and honey. Fructose 
which is very much like glucose occurs in soft fruits. Glu- 
cose is not poisonous as some persons think. The chief 
reason for objection to its use in manufactured food prep- 
arations is that it is not as sweet as cane sugar. Another 
reason is that glucose is often used by manufacturers because 
of its cheapness, while the price charged for the product 
is the price of the pure, unadulterated food. Before the 
United States Pure Food Law went into effect in 1900, it 342 
TIIE SOURCES OF OUR FOOD SUPPLY 
was the frequent custom of some manufacturers to deceive 
the public, by failing to state on the package that glucose 
was present, and also deliberately to deceive by intimating 
that no glucose could possibly be present. For example, in 
the discussion in Congress preliminary to the passage of the 
first Food Law a Congressman exhibited the handiwork of 
one firm that was selling so-called strained honey which was 
made up of honey and 
artificial glucose. In 
order to make the de- 
ception complete, a 
dead honey bee had 
been placed in the 
bottle. 
Saccharose is ob- 
tained from the sugar 
cane grown in the 
Southern states, in 
Cuba, and in Hawaii. 
It is also obtained from 
the sugar beet which 
is grown in some of our 
Northern states, and in Europe. Saccharose is also to be 
found in fruits and in maple syrup. 
Maple sugar is obtained from the sap of the sugar maple, 
and is collected by boring holes in the trunks of the trees 
in February or March, after the first warm weather at the 
breaking up of winter. The sap is boiled down considerably 
for making syrup, and still more for sugar. Everyone who 
gets his maple syrup directly from the farmer believes that 
at least his sugar is pure. As a matter of fact, many sugar 
makers honestly believe it improves the making of the 
syrup to put brown sugar into it, and they very commonly 
do it. Nevertheless, the flavor of maple sugar is nearly 
always satisfactory. 
Fig. 179. Some Foods that Contain Sugar. 
Milk, jam, sweet potato, carrot, onions, 
honey, corn, apple, syrup, beets, orange. STARCH 
343 
Sugar also is consumed by us in combination with other 
nutrients in certain foods. Among the most important of 
these are the sugar of milk, sugar in vegetables such as 
sweet potatoes, beets, carrots, turnips. 
All our fruits contain sugar, the apples, the pears, the 
cherries, the plums, the prunes, the figs, the dates, etc. 
The fact is soft fruits 
have practically no 
other organic nutri- 
ent, except small 
quantities of inor- 
ganic salts. 
Sugars in general 
are easily digested. 
Glucose needs merely 
to be absorbed, since 
that is the form of 
sugar found in the 
blood itself. When 
carried about to the muscles, digested sugar is oxidized 
quickly, and yields energy for rapid use. 
Starch. In nearly pure form starch is obtained from 
potatoes and from corn grains. The best known food form 
of starch is corn starch. Other foods that contain large 
quantities of starch are tapioca, sago, sweet potatoes, tur- 
nips, carrots, parsnips, peas, beans, and all cereals. Wc 
eat far more starch than we do of sugar, but when the starch 
is consumed, beginning at the mouth itself a chemical change 
takes place. Starch is changed to glucose. You may no- 
tice it happening in your own mouth by chewing for a long 
time any cereal, or in fact a piece of bread. The saliva con- 
tains the chemical called an enzyme, which makes the trans- 
formation. The fact is, one may insure his digestion of 
starch by chewing it until it begins to taste sweet. Al- 
Pig. 180. Some Foods that Contain High 
Percentages of Starch. Bread, sweet 
potato, white potato, beans, peas, oatmeal, 
carrot, corn, hominy. 344 
TIIE SOURCES OF OUR FOOD SUPPLY 
though starch is digested in the intestine also, the best plan 
is not to depend too much on what the intestine is going to 
do. A stomach-ache sometimes comes from the rapid swal- 
lowing of a dish of oatmeal. 
Fats. The chief source of fat or oil is animal. Butter 
is nearly all fat, but a great deal of fat is derived from cheese 
along with other nutrients. The fat in milk rises with the 
cream on the principle 
that oil is lighter than 
water, water being the 
chief ingredient of milk. 
Many persons are averse 
to eating the fat of meat 
on the ground that it is 
indigestible. If it is indi- 
gestible it is because it 
has not been cooked 
properly. When well 
cooked the fat of beef, 
mutton, or pork is quite 
digestible. As a rule one 
eats more fat than one 
supposes, on account of much fat being mixed with the lean. 
Naturally, the amount of fat one eats will depend largely 
upon the external temperature. Wherever a person is, he 
ought to digest easily all the fat his natural longing demands 
he should eat. 
The commonest of food fats or oils from plant sources, 
or as they are called, “vegetable oils,” is olive oil. This is 
obtained by pressing the pulp of ripe olives in a vat. The 
most common use made of olive oil is as an ingredient of 
salads. On account of the expense of this oil, there are being 
tried preparations of cotton seed oil, of corn oil, and also of 
peanut oil. The latter seems to be preferred to the cotton 
Fig. 181. Some Foods that Contain Oil. 
Milk, peanut butter, cheese, meat, egg, 
hickory nuts, butter. PROTEINS 
345 
seed oil, although both are wholesome. It has been explained 
already that fats or oils yield very large amounts of energy in 
the form of heat or muscular energy. To a slight extent fat 
becomes fat again in the body, but this is not the common 
result of its use. You may be surprised if you learn that 
one of the first foods in meat form given to very young 
children is a piece of well-cooked bacon. You may see the 
reason if you recall the excessive activity of a healthy baby. 
Proteins. Proteins are often spoken of as nitrogenous 
foods, on account of their being the only class of nutrients 
that contain nitrogen. There are many kinds of protein, 
but for our purpose it is not necessary to distinguish between 
them. The fate of all kinds of protein in digestion is much 
the same. Protein is present in many of our foods, but it is 
especially abundant in the lean of meat, in the white of 
egg, in milk, cheese, cereals, peas, beans, and nuts. 
For a long time physiologists and reformers in matters 
of eating have been studying and discussing the question 
of whether it is necessary to obtain some of our protein from 
meats. Naturally because of the growing feeling of sym- 
pathy for the lower animals, there has arisen the conviction 
on the part of some that we do not need to eat flesh, because 
the physiological chemists have shown that protein may be 
obtained in plentiful quantity from eggs and milk, and even 
from vegetables, from seeds of many kinds, and from nuts. 
The question is still an open one so far as decision on the 
point of the workableness of a purely vegetarian diet is 
concerned. There is no doubt whatever that beans, for 
example, contain nearly as much protein as some meats, 
or even more than some, and that nuts are very rich in this 
nutrient. The requisite amount of material for repair could 
easily be obtained from plant sources without overloading 
the digestive system with other nutrients, and it could be 
done much more cheaply than it could be done with a meat 346 
THE SOURCES OF OUR FOOD SUPPLY 
diet. Many persons who have experimented with eating 
vegetable compounds of foods that are intended to replace 
not only the habit but also the taste for eating meat, say 
that the vegetable compounds lack the agreeable flavor of 
meat. After a few trials, the tendency is for experimenters 
to go back to the habit of eating meat. 
Furthermore, in the analysis of lean meat there has been 
discovered a substance 
called creatin. This is 
the substance that 
gives to meat its 
pleasing flavor. In 
fact, it stimulates the 
appetite. Creatin is 
used in soups for the 
very purpose of stimu- 
lating the appetite in a 
natural way. The veg- 
etable compounds seem 
to be lacking in this 
material, as they are 
lacking in certain other 
substances believed to be essential to proper digestion, and 
to the proper building of tissue. 
We cannot hope to induce persons in the mass to quit 
eating meat unless we give them a substitute that really 
satisfies the taste, as well as provides the requisite nourish- 
ment. However, there is one thing which we hope to be 
able to do, and that by offering a substitute which is not 
only as good, but is even a great deal better. This substi- 
tute is to eat less, and thereby to enjoy life longer. This 
matter will be taken up for discussion in the next chapter. 
Inorganic Nutrients. Water is the commonest of the 
inorganic nutrients and the cheapest, except when we buy 
Fic. 182. Some Foods that Contain Much 
Protein. Milk, cheese, oatmeal, hominy, 
meat, bread, peanut butter, peas, beans. OTHER IMPORTANT SOURCES 
347 
it in combination with expensive foods. In all drinkable 
water, except rain water or distilled water, we consume also 
carious kinds of inorganic salts, mineral elements in com- 
bination with others. One of these is often common salt 
itself, sodium chloride. The principal elements of these 
salts are also found in many of our foods. 
Iron is of especial value in forming a necessary compo- 
nent part of hemaglobin, 
which is found in the red 
corpuscles of the blood. 
Hemaglobin unites with 
oxygen which is thus car- 
ried from the lungs to be 
released wherever oxida- 
tion is going on. A per- 
son whose red corpuscles 
lack iron is pale or 
anaemic. We may obtain 
iron from vegetables, 
such as asparagus, spinach, lettuce, carrots, parsnips, beets, 
grains, nuts, eggs, and from meat. 
Calcium and magnesium salts occur and are needed in 
the bones and in the soft tissues and fluids of the body. 
Calcium salts must be available for the contraction of mus- 
cles. Calcium is found in cereals, fruits, vegetables, cheese 
and milk. Magnesium is consumed with cereals, vegetables, 
fruits, nuts. 
Sodium, sulphur, potassium, and phosphorus salts are 
found in the living tissues of the body, and are supplied 
from milk, cheese, eggs, cereals, vegetable nuts, fruit. 
Other Important Sources of Nutrient Supply. Whole 
wheat bread, graham bread and bread made from patent 
flour, contain the outer parts of the grain which are rich in 
mineral salts. 
Fig. 183. Some Foods that Contain 
Much Iron. Lettuce, oatmeal, meat, 
carrot, beans, egg, peanut butter. 348 
THE SOURCES OF OUR FOOD SUPPLY 
Butter is the most digestible of fats; 97 per cent, of it is 
available as food, the highest percentage of any food. Cheese 
is a staple article of food, and one pound contains as much 
protein as one and one-half pounds of meat. 
The yolk of eggs is a very valuable food for growing chil- 
dren, by reason of its richness in protein, fat, lime, iron, 
and phosphates. Nine average eggs of one and three- 
quarter ounces each contains as much nourishment as is 
contained in a pound of meat. 
An ounce of oatmeal contains more nutriment than one 
ounce of the usual proprietary breakfast foods. 
Legumes (peas and beans) are especially rich in nitrogen, 
the chief element of protein, because of their power to fix 
nitrogen from the air. They are also rich in starch. How- 
ever, a too free use of legumes except by persons of vigorous 
constitution, leading outdoor life, brings on indigestion and 
flatulence. 
Nuts are rich in fats and protein, but the nutrients are 
inclosed in dense cellulose fiber, making digestion difficult. 
Fresh fruits and green vegetables are not eaten so much 
for the nourishment they contain as for the salts of potas- 
sium, lime, and sodium they have. 
There are certain unmodified foods that can be depended 
on to supply all that is necessary to living: grains, vegetables, 
fruits, meats, eggs, milk. Artificial foods are inadequate 
of themselves. They are: corn starch, sago, tapioca, syrups, 
sugars, butter, lard. 
Vitamins. Since the year 1911 a great deal has been 
learned about the fundamental conditions of nutrition 
through experimentation with the vitamins. In that year 
Casimir Funk, a German physiological chemist working in 
America, gave this name to a newly discovered substance in 
foods which he believed to be curative of an oriental disease 
called “beri-beri” This disease is common in Japan, the VITAMINS 
349 
Philippines, and in other oriental countries where the diet 
consists largely of polished rice. Mr. Funk obtained from 
rice polishings a substance which he fed to birds that had 
been given polished rice to eat for some time. The result 
was that the birds recovered from beri-beri, which they had 
as the result of eating only polished rice. Mr. Funk named 
the new chemical substance “Yitamine” to indicate its im- 
portance and its chemical nature. The word is made up of 
two words, vita, life, and amine, which is the term used by 
chemists to apply to substances containing nitrogen. How- 
ever, long and careful study has not shown that the vitamins 
do contain nitrogen, or what the chemical composition of 
this product really is. But of the physiological nature of the 
vitamins there is very definite knowledge, as there is also of 
the sources of the vitamins in food. 
The vitamins are known as Vitamin “A,” Vitamin “B,” 
and Vitamin “C.” Doubtless when chemists know the com- 
position of these substances they will propose discarding 
these letters, and will give them more descriptive names. 
With the names “A,” “B,” and “C” go terms which de- 
scribe their physical nature in solutions. Vitamin “A” is 
said to be fat-soluble, “ B ” and “ C ” are water-soluble. This 
means that they are capable of dissolving in fat, or in water. 
The numerous experiments that have been carried on 
with foods in their effects on man and other animals show 
with very little question that certain “deficiency” diseases 
are due to the lack of one or another of the vitamins, and 
that when the vitamins are supplied the deficiency diseases 
are cured. The commonest of these diseases is “rickets.” 
Sometimes children have weak legs. This may be because 
they have not been given the food that will cause their 
protoplasm to lay down lime in the bones. Beri-beri, scurvy, 
and probably pellagra are other deficiency diseases traceable 
to the lack of one or another vitamin. 
Besides having the property of preventing deficiency dis- 350 
THE SOURCES OF OUR FOOD SUPPLY 
eases, the vitamins have the still more general and important 
property, especially for children, of stimulating growth. It 
is now positively known that if a person or an animal con- 
sumes enough protein, starch, sugar, fat and mineral sub- 
stances to furnish all that is needed to keep up the waste 
of protoplasm, and for energy, and does not have the vita- 
mins, life will continue no longer than when nothing at all 
is eaten. Thus, if a child is undersized it is certain that it 
has been given foods that do not contain enough of these 
vitamin products. 
We must know, therefore, how to secure for the children 
adequate supplies of Vitamin “A,” “B,” and “C.” Vitamin 
“A,” fat-soluble is found plentifully in milk, butter, cream, 
mutton fat, beef fat, and also in various lean meats, in eggs, 
in the germs of wheat, corn and rice, in many vegetables, 
and in seed foods. Vitamin “B,” water-soluble, is found in 
lean meats, eggs, whole grain cereals, yeast, many vegetables, 
seeds, fruits, nuts, milk, even in skim milk. Vitamin “C,” 
the most recently discovered vitamin, the one believed to 
prevent scurvy, has been found in lean meat, in vegetables, 
and in fruits. 
Babies are given orange juice early. It is now known 
that tomato juice, even the juice of canned tomatoes, con- 
tains the valuable vitamins which stimulate growth. Green 
vegetables are disliked by many children, especially spinach, 
carrots, and the like. But the grown-ups owe it to their 
children to train them to eat as many green vegetable foods 
and salads as possible, at least once a day. In a former 
section you learned about the existence of minerals in the 
vegetables. We have now added the vitamins to our store- 
house of useful knowledge. CHAPTER XXX 
WHAT TO EAT, HOW MUCH, AND WHY 
Why Some Grow Old Early. If you have been ob- 
servant, you are acquainted with persons of forty to fifcy 
years of age who seem about as old as other persons among 
your acquaintances who are seventy to eighty years of age. 
They are really quite as old in the physiological sense. 
Between 1895 and 1900 several articles and books were 
written by some of these old young men telling of their ex- 
periences in breaking down in the prime of life, suddenly 
realizing it, and then trying to “pull themselves together.” 
Those who have published their stories were of course able 
to get back to what they believed to be their normal con- 
dition, but the many hundreds and possibly thousands of 
others who have tried to regain their health, and have 
failed—these persons never write stories of that kind. Or if 
they should, no one would publish them, for the thoughts 
and the troubles of dyspeptic persons would not make ac- 
ceptable reading. 
From Old Age to Youth. One of these sometime chronic 
dyspeptics, perhaps the best known of them all, because of 
the entertaining stories he has written of his experiments, is 
Mr. Horace Fletcher. At the traditional age of early break- 
downs he suddenly found himself near the end of his physio- 
logical tether. He began to experiment with eating less and 
less, and chewing everything he ate until all kinds of food 
he took were reduced to a liquid condition. Before long he 
was able to eat anything he liked, and as much as he liked. 
Curiously enough he found that he was eating less than he 
351 352 
WHAT TO EAT, HOW MUCH, AND WHY 
had formerly eaten, and that his temperament was cheerful, 
and most surprising of all, his strength was greater than it 
had ever been. He was then about fifty-five years of age. 
In order to test the value of his experiments scientifically, 
he put himself under the direction of Professor Chittenden, 
of Yale University, one of the foremost food experts and 
physiologists in our country. Mr. Fletcher’s body efficiency 
was tested in certain strength 
measurements, the same that 
arc given to the athletes of 
the University. The result of 
the tests showed that Mr. 
Fletcher was stronger than 
any of the young fellows in 
the athletic squads. 
The explanation of this re- 
markable result was that Mr. 
Fletcher not only got every 
bit of energy his food con- 
tained by thoroughly pre- 
paring it for digestion and 
assimilation, but also that his 
body was free from all the 
weakening poisons which de- 
velop from unused foods dur- 
ing the attempts of over- 
worked organs to dispose of 
them. This leads us to wonder what the Yale crew itself 
might not be able to do if the members followed a better 
system of eating. 
Eating as a Habit. We are told by those who have 
passed through the horrors of trying to break such vicious 
habits as drinking alcoholic liquors and smoking opium, that 
the misery is indescribable. Although one who overeats 
Fig. 184. Horace Fletcher. 
(Courtesy of Frederick A. Stokes 
Company.) THE CHIEF BAD HABIT IN EATING 
353 
does not suffer to that extent when trying to reduce the 
quantity of food consumed, the habit may be even more 
firmly fixed because of the fundamental necessity of eating 
something. It is natural for us to live without drinking 
alcohol or smoking opium, but it is not natural to go without 
eating food. Then again, one may suffer from placing him- 
self in a situation where he will be over-stimulated to eat 
excessively. This result might come from eating highly 
spiced, stimulating foods, and from eating in large companies 
in restaurants where the noise and the music break down 
the resistance of a normal mind that pays attention to what 
its body is doing. Under these conditions, one is led on 
and on by enticing flavors, forgetful of the fundamental 
purpose of eating. Those who are in the business of man- 
aging fashionable restaurants have other desires than those 
that are best for persons who want to get the most in hap- 
piness and efficiency out of their bodies. 
It took a long time for the excessive drinking of intoxi- 
cating liquors at table to come to be regarded as vulgar 
even by well-mannered persons. It may take a longer time 
for the vulgarity of overeating to strike the minds of per- 
sons of good breeding. However that may be, our genera- 
tion even now could avail itself of the facts which show that 
overeating is the cause of monstrous waste in the world’s 
happiness and in its ability to get things done, and done well. 
The Chief Bad Habit in Eating. It is becoming clear 
to many well-informed persons that our greatest single mis- 
take in eating is consuming too much meat. Meat affords a 
large amount of protein. In our country it is a frequent 
custom to eat meat at every' meal of the day. An indication 
that this is not necessary is to be found in the fact that 
Europeans seldom have meat for breakfast. And some 
Europeans, especially the Italians of the poorer classes, 
seldom have meat at any meal. Millions of Japanese, the 354 
WHAT TO EAT, IlOW MUCH, AND WHY 
Chinese, and the East Indians ordinarily do not have meat 
at all, living on little else than rice. Some have rice and 
fish. But since the Russo-Japanese War the Japanese have 
been eating much more meat, because the experience of that 
war seemed to indicate that the use of meat enabled the 
soldiers to put forth greater efforts in their hard marches. 
The Chinese are now raising hogs and other animals for 
meat more than they ever have before. 
Where to Begin to Reform Easily. Experiments and 
observations carried on by food experts in Europe and in 
America show considerable variation in what may be the 
real needs of the human body so far as protein for the repair 
of the worn-out tissue is concerned. The estimates of the 
need given vary from two to six ounces. These amounts 
mean the dry protein without estimating the water and 
other nutrients contained in the food. The lower estimate 
would imply practically eating meat once a day, the higher 
at least twice a day. The strong tendency, however, is to 
reduce the meat ration to once a day. The first change that 
one might make in the reform of eating, and make without 
a serious feeling of being deprived of a need, would be this 
reduction in protein consumed. 
You might notice then what foods you eat which seem to 
belong to one another in a sense. You realize that bread 
and butter go together. The reason is that they comple- 
ment one another in making up a balanced ration. Un- 
doubtedly the human race has discovered facts of this kind 
by crude experiment. The bread contains the protein and 
the carbohydrate, and the butter contains the fat. Another 
composite food is pork and beans, there being mostly fat 
in the pork, and protein and starch in the beans. This, by 
the way, is a food which is staple over a great portion of the 
world, and is much relied upon in armies and in working 
camps for railroad construction and other public improve- PLANNING BEFORE EATING 
355 
merits. Meat and potatoes also complement one another. 
Macaroni and cheese are much relied upon by the Italians 
for protein, starch, and fat. These facts are already in our 
possession from the experience of the race. We can begin 
right there, and build upon the information. 
Persons who cannot afford more than one main dish at 
dinner do not have more than that, and usually get along 
very well, provided the dish is one of the natural comple- 
mentary combinations. Those who can afford for dinner 
soup, fish, entree of meat, a 
roast, three vegetables, salad, 
dessert, crackers and cheese, 
and coffee, very often try 
to have them all. They 
probably wonder how the 
poor manage to live. The 
poor, if they are intelligent 
and fortunate enough not to 
be blinded by envy, may 
wonder how the others man- 
age to live. The worst of the tendency to one extreme is 
that the poor have too little, if not in quantity, then cer- 
tainly in variety, which often amounts to the same thing, 
for the reason that sameness prevents the occurrence of a 
healthy appetite. 
Thinking and Planning Before Eating. The planning 
of a bill of fare for a family requires as much judgment as 
does any other piece of wrork involving important conse- 
quences. If one has ham for breakfast, it might seem to be 
traditionally required that he should have eggs also. But 
if he recalls the composition of those foods he will see that 
he is duplicating both protein and fat. There would be no 
objection to having the ham and egg, provided the usual 
portion were cut in two, and enough bread and cereal were 
Fig. 185. Groups of Complemen- 
tary Foods. Bread and butter; 
meat and potato; pork and beans. 356 
WHAT TO EAT, HOW MITCH, AND WHY 
added to give a balanced ration, and further provided, that 
a person did not have the same kind of strong food for dinner 
also. Many persons think they must have ham and eggs 
for breakfast, whatever else they may have to go without. 
The fact that they live after thus indulging themselves only 
shows how resistant is the human constitution. Similarly, 
if one has beef, a large plate of beans is a duplication 
of the protein. Other faulty duplications are chicken 
soup and boiled chicken; white potatoes and sweet pota- 
toes, the starch being duplicated here. Still others are made 
by families that think they must have three vegetables at 
dinner. 
The “high cost of living” characteristic of our time, has 
at least one phase which is not without benefit to us. It has 
given the stimulus to many families that must try “to make 
both ends meet” to find some way to accomplish that great 
object. Necessity lends an important aid to intelligence. It 
is important in the interest of the family exchequer to know 
that the cheapest foods which are available as fuel to supply 
energy are rice, potatoes, bread, beans, macaroni, and corn. 
Fats are somewhat more expensive, and proteins are a great 
deal more expensive. 
One of the best of menus for a growing boy or girl of high 
school age is given by Professor W. S. Hall, in his book, Nu- 
trition and Dietetics. The recommendations are based on 
important fundamental principles, which will be explained 
wherever it is necessary. 
Breakfast 
A cereal with cream and sugar 
Buttered toast 
Cereal coffee 
One boiled egg 
Fruit (grapes, apples, bananas, oranges or berries) TIIE PRINCIPLES APPLIED 
357 
Lunch 
A puree or cream soup with crackers or croutons 
Bread and butter 
Fruit 
Rice pudding or custard 
An ample portion of meat 
Potatoes (baked or boiled) 
Side dish of vegetables 
Fruit, stewed or canned, with graham wafers 
Dinner 
This menu is enough for an adult also, at least for one who 
is doing work that does not require a heavy expenditure of 
physical energy. 
Professor Hall recommends that if girls feel exhausted 
by the work at school, they may in addition when they reach 
home make for themselves an egg lemonade, using the yolk 
only of two eggs with half a lemon. This will give them re- 
newed vigor, the egg supplying iron for the red blood corpus- 
cles, and will not interfere with an appetite for dinner. Fur- 
ther, it is permitted with the calculations upon which this 
menu is based to eat candy (most blessed of concessions!), 
provided, the candy is eaten immediately after a meal. 
The Principles Applied. It will pay us now to take up 
and consider the menus of the three meals, and thus to com- 
prehend the principles that underlie the suggestions. It is 
necessary to understand principles, because they contain the 
reasons. Otherwise you may be trying to remember sug- 
gestions which you do not understand. The cereal contains 
a fairly large quantity of protein, and a considerable quantity 
of starch. With the sugar added, and the cream, a well bal- 
anced food is obtained in this one combination, and also 
a very palatable food. There is the objection to soft cooked 
cereals that they do not require chewing to prepare them for 
swallowing. As was stated in the last chapter cereals should 358 
WHAT TO EAT, HOW MUCH, AND WHY 
by all means be chewed. Even with chewing, the gums and 
teeth need the exercise they will get from chewing buttered 
toast. That is why the toast is introduced. Besides, the 
bread and butter make a very delicious balanced food, pro- 
vided it is not allowed to stand while the toast becomes cold. 
Cereal coffee is recommended as a substitute for the berry 
coffee. It is nourishing and not merely stimulating. Few 
persons realize that berry coffee contains no energy-produc- 
ing food whatever, except the cream and sugar used with it. 
Eggs contain protein and fat, and another ingredient already 
mentioned—iron. Many young persons tend to become 
anaemic; that is, they do not have enough haemaglobin in their 
red blood corpuscles. The iron from the egg makes it pos- 
sible for the haemaglobin to carry more oxygen. Tincture 
of iron when used as a tonic only stimulates the body to use 
the iron in the food, and cannot supply the needed iron it- 
self. Fruits contain sugar which supplies energy for work. 
They also contain palatable flavors, the acids necessary to 
counteract alkalis in food, and the mineral salts, the latter 
being very necessary to supply material for building bone. 
The lunch is very simple, and, even if variety is obtained 
by having foods of similar nature, may not appeal to those 
who have been going to the delicatessen counter for frank- 
furters, or to the push-cart for “hokey-pokey” and “ lolly- 
pops.” However, those who follow the suggestions offered 
will have less trouble than others on the morrow, and on the 
days after that. The soup is warm, making the stomach 
feel comfortable at once. The ingredients are protein and 
starch, and with cream, all three organic nutrients are pres- 
ent. The crackers have a small quantity of protein and 
starch, giving the teeth something to do. Bread and butter 
is the balanced food used by everyone. The rice or custard 
pudding, contains protein, starch and sugar, and in the case 
of custard, fat as well. 
The dinner may look like a starvation allowance to those THE PRINCIPLES APPLIED 
359 
who think they must have a seven-course meal. But really, 
does it not offer the possibility of great relief from the neces- 
sity of having an enslaved being standing behind us at table, 
as well as having enslaved beings sitting in our chairs? No 
great worry here whether you have taken up the pieces of 
cutlery in the correct order, because if you are firm in your 
desire for simplicity of 
living, you will have this 
dinner or another like it 
as a guest, and at home 
also. Besides, there will 
be less of formalism, and 
more time for sincerity, 
fewer dishes to wash, and 
more time really to live. 
The spirit of slavery to 
fashion is responsible for 
the elaborate meals pre- 
pared for well-to-do 
American families to- 
day. Excessive eating 
is not only unneces- 
sary, but it makes real, hard, and useless work. 
But to the other reasons for eating this dinner. The meal 
yields the well-known protein, some fat, the creatin whicl 
stimulates appetite, some iron for the red corpuscles, anc 
some inorganic salts for the bones and the nerves. It reall} 
seems we could not get along without meat. Potatoes are th< 
“foil” for the meat; they contain the starch, and on trans 
formation to glucose yield energy. Besides being generally 
cheap, potatoes yield a large amount of alkaline ash or min 
erals. These alkaline minerals help in counteracting the 
uric acid which results from the oxidation of the waste 
products of meat. An excess of uric acid is believed to be 
related to the development of rheumatism. 
Fig. 186. Group of Healthy Children 360 
WHAT TO EAT, HOW MUCH, AND WHY 
The side dish of vegetables might be carrots, beets, tur- 
nips, cabbage, spinach, chard, cauliflower, or kohl-rabi. 
Others might just as well be taken instead. The green vege- 
tables contain iron as well as other inorganic salts, the im- 
portant elements of which are calcium, magnesium, sul- 
phur, sodium, phosphorus (see p. 347). The others contain 
starch, protein, and a little sugar. 
The menus here recommended are supposed to be sufficient 
for young students, and for adults engaged in the moder- 
ately hard pursuits of life. This means that along with the 
regular daily wrork in school, or at any kind of wrork at which 
young persons engage normally and safely, this amount of 
food is enough to supply all the normal waste of muscular 
tissue, and enough to yield the requisite amount of energy 
through the oxidation of sugar and converted starch and fat 
to keep the body warm in all kinds of temperate climate 
weather, and enough to give the energy needed for muscular 
exercise. Because the amount is not great, the tendency 
will be for all the food to be really assimilated, that is, to 
become a real part of the tissue of the body, or to yield en- 
ergy for its immediate use. Whatever we do, we must not 
store up poisons in the body, and hasten the day of physiolog- 
ical old age. CHAPTER XXXI 
THE CARE AND THE PREPARATION OF FOOD 
Old Prejudices and New Ideas. There was once a man 
who on arriving with his family in a country place on a July 
day endeavored to make arrangements with a farmer’s wife 
to furnish artificially cooled milk for his baby girl for the sum- 
mer. The man explained that if fresh, warm milk is set im- 
mediately in pans in a tub having cold water in the bottom, 
many bacteria that naturally grow in milk will be prevented 
from developing. “Nonsense,” replied the woman, “Just 
look at my boys! Do they look as if germs had hurt ’em?” 
There are many persons who naturally resent any inter- 
ference with their old ways of thinking and doing, and some 
especially resent the changes that science is slowly but surely 
making in their environment. And besides, it is a common 
fault of mankind to reason from a limited number of facts. 
It is not known whether this particular woman had lost any 
sons in infancy, but we all know cases of families that lose 
young children from intestinal troubles in summertime. 
Without question most of these cases are due to milk that 
has not been properly cared for. 
Experience, the Source of New Ideas. The laws that 
govern the sale and distribution of milk in large cities are 
based upon the tragic experience of thousands of bereaved 
parents. Nobody guessed it would be a good thing to have 
laws to control the milk collecting and distributing industry; 
we have absolute knowledge of facts upon which public 
judgment was based. But the laws are not strict enough, 
or at least they are not enforced rigidly enough. Milk con- 
361 362 
CARE AND PREPARATION OF FOOD 
tains the bacteria that cause intestinal trouble in babies. 
These bacteria can be prevented from developing in danger- 
ous numbers only by immediate cooling. At the same time 
the souring bacteria of milk may be kept in check by the 
cooling process. Souring bacteria are not disease bacteria, 
but souring renders the milk unfit for general use. Certain 
communicable diseases are easily carried in milk, especially 
typhoid fever and diphtheria. These may make their way 
into the milk through the 
carelessness of the per- 
sons who do the milking. 
A person with one of 
these diseases may be on 
the farm, or on an adja- 
cent farm which is con- 
nected through the water 
supply, and through care- 
lessness in disposing of 
sewage the water supply 
may become infected. Or 
flies may go from filth 
which contains the germs 
of disease to the milk 
pails or other vessels. 
Agents of the depart- 
ments of health in large 
cities in our country not only examine samples of milk 
furnished by the milk companies as the milk reaches the 
cities, but other agents visit the dairies, in some cases hun- 
dreds of miles from the cities, and there make inspection 
of the premises. Infected milk is condemned, and dairies 
found to be supplying impure milk are prevented from sell- 
ing any milk until the premises are set in order. 
Although laws give the city a measure of protection from 
disease through its milk supply, there is no plan for protect- 
Fig. 187. Milk Inspection Scene. Ex- 
amining Petri dish cultures for bacteria 
colonies in Department of Health, New 
York. (Photo, by A. Tennyson Beals.) EXPERIENCE, THE SOURCE OF NEW IDEAS 
363 
ing the families in the country itself, where there are no 
city-delivering dairies, or for protecting the families in small 
towns. These families have to take their chances. One of 
the results is that the public health in the country in typhoid 
is not so good as it is in the cities. 
Although it is very important to care for the milk of a 
community, the public health and also the general need of 
economizing, make it highly desirable to know something 
about why other foods also should be looked after before they 
are brought to the kitchen for cooking. 
DEATH RATE PER 100,000 OF POPULATION DURING 1917 
IN REGISTRATION STATES 
Diseases 
Average 
Cit ies in 
Reg. States 
Rural Part 
of 
Reg. States 
All Causes 
1,401 
1,515 
1,298 
Typhoid 
13.3 
10.1 
16.2 
Measles 
13.7 
10.1 
17.0 
Scarlet Fever 
3.5 
4.0 
3.0 
Whooping Cough 
10.5 
9.4 
11.6 
Diphtheria 
15.7 
19.4 
12.3 
Tuberculosis of the Lungs 
126.6 
138.1 
116.3 
Cancer 
81.2 
94.4 
69.3 
Diabetes 
16.9 
20.1 
14.1 
Organic Heart Disease 
152.9 
168.5 
139.0 
Pneumonia 
147.2 
177.3 
120.3 
Acute Nephritis and Brights 
Disease 
105.3 
123.0 
89.5 
Violence 
93.7 
104.5 
84.1 
Suicide 
12.9 
15.9 
10.3 
(Analysis made by Mr. Frederick L. Hoffman, Statistician of The 
Prudential Insurance Company of America.) 364 
CAKE AND PREPARATION OF FOOD 
The Cold Storage System. In these modern days there 
has developed the cold storage system of keeping vege- 
tables, fruits, eggs, and meat. There exists a great deal of 
prejudice against the idea of keeping food in this way. But 
chemical and bacteriological examinations tend to prove 
that no injury results to the food. They are just as health- 
ful as fresh foods, unless the food was bad when it was put in 
storage. The fact is that the cold storage method has made 
it possible to obtain certain articles of food throughout the 
year that formerly coidd be obtained only for a limited pe- 
riod. Food is kept in cold storage by commercial firms en- 
gaged in the business, but to a certain extent separate fami- 
lies may find it convenient, and certainly economical to keep 
fruit, vegetables and even eggs (preserved in “water-glass”) 
buying them in large quantities when they are cheapest, and 
protecting them in clean, cool, dry and dark cellars, or better 
in cold storage rooms, constructed so as to have two to four 
walls with inclosed air spaces or with sawdust. Many popu- 
lar scientific periodicals give directions for making these 
rooms. 
Carrots, parsnips, etc., may be buried in dry earth or sand 
in the storage room or cellar. Potatoes should be kept in a 
cool dark bin. Apples should be culled and wrapped and kept 
in a temperature just a little above freezing; some house- 
keepers do not open barrels of apples until they are ready 
to use them. Smoked meats should be kept in a well venti- 
lated cellar. 
Bread and vegetal)les must be kept free from molds; 
cheese and meat must be kept away from the flies because 
of the danger of typhoid fever being carried into the food, 
and also for the reason that flesh-flies and certain other 
flies lay their eggs on these foods. The eggs produce the 
“maggots” or larvae that spoil the food. Screens will keep 
the flies from the meat, but they will not keep out the bac- 
teria. Partially decayed flesh is one of the most dangerous COOKING 
365 
of all substances to eat, because of the possible presence 
of “ptomaines,” which are the poisonous excretions of cer- 
tain bacteria. 
Chemical Preservatives. In addition to low tempera- 
tures, man has discovered other means of preserving foods, 
the most familiar being salt, sugar, and vinegar. In more 
recent years other chemical products have been employed 
in certain cases. The best known of these are, salicylic 
acid (water-glass), formaldehyde, boric acid, and benzoate 
of soda. A very little formaldehyde will keep milk fresh 
for a month, but formaldehyde is a deadly poison in quan- 
tities a trifle larger than is sometimes used for preserving 
milk. Hence its use should never be permitted. Benzoate 
of soda has been the center of a long warfare between cer- 
tain groups of chemists in this country. But it appears to 
be conceded now that this chemical is not injurious. It is 
used in keeping food from showing incipient decay. 
Cooking. We have inherited two traditions about 
cooking. One is that only girls need to know about cook- 
ing; the other is that there is nothing so good as home cook- 
ing. The first tradition persists in spite of the fact that 
cooking is a profession with many men, especially in France, 
Germany, and Italy. Besides, the tradition is pointless 
anyway, for we all eat. The other tradition persists and 
is thoroughly believed in by nearly everyone. But each is 
thinking of his own family, whose cooking he became used 
to during the first part of his life. As a matter of fact, home 
cooking is often “villainous.” If you were not brought up 
on saffron-colored biscuits and on beefsteak fried until it 
resembles leather in hardness, and on pancakes and ham 
always at breakfast, on greasy doughnuts, and on vinegar 
pie (there is such pie), then you are the proper person to test 
scientifically the value of home cooking. If your stomach 366 
CARE AND PREPARATION OE FOOD 
does not resent the insult, a few repetitions will compel it to 
do so. The superior quality of home cooking is largely in 
the imagination. 
There are truly scientific principles in cooking, which in 
general have not been worked out in the home where a num- 
ber of other industries are in operation. Men ate food before 
there was any cooking. In all probability the discovery 
of cooking was an accident. Charles Lamb in his delight- 
ful essay on Roast Pig may not have missed by far the actual 
way of the introduction of cooking. Cooking makes things 
taste better, and nobody could have foretold that. There- 
fore, the cooking which makes things taste best is the best 
cooking, provided of course that no practical danger to the 
digestion has been introduced. 
Another principle of cooking which also must have been 
discovered by accident is that it makes easier the division 
of food into eatable particles. This comes about by the 
softening of the cell walls of plant tissue (the cellulose), by 
the swelling or bursting of the starch granules, and by the 
changing to soluble gelatine the tough connective tissue of 
meats. The advantage has been that one could eat all he 
required in a much shorter time than was possible formerly, 
and the digestive fluids could more easily reach the smallest 
particles of the food, provided too much is not swallowed 
at one time. 
In America vegetables are commonly brought into the 
necessary softened condition by cooking in water, after which 
the water is thrown away. Incidentally, a great portion 
of the easily soluble mineral salts so abundant and valuable 
in vegetables goes into the sink with the water. Europeans, 
especially the French and the Italians, cook many of their 
vegetables in butter or in oil, using no water at all except 
such as boils out from the vegetables. This is always enough 
to prevent the scorching of the vegetable tissue. Our 
American way seems to amuse European experts in the art COOKING 
367 
of preparing food. We cannot deny that we are often in- 
dictable on the score of national wastefulness. 
One of the principles ignored in that form of home cook- 
ing which produces the leathery steak is this: The juices of 
meat may be retained only by a rapid searing of the surface, 
followed by a slower softening of the fibrous tissues through 
the application of less heat. All roasts are properly cooked 
in this way. If the cooking is prolonged the juices will all 
be driven out, or dried up altogether. Thus primitive cook- 
ing, such as encasing the cleaned fowl or fish in wet paper 
plastered over with mud, and the whole placed in ashes, 
with a fire burning above is the very best, for none of the 
juices can escape. Try this while you are camping, and 
you will agree that you never ate delicious meat before. 
On the other hand, if you desire to extract fluids from the 
meat or the vegetables, the cooking should be done slowly, 
starting in cold water, and heating for a considerable time 
over a slow fire. This is the way to prepare soups. 
So much misery has resulted from the general practice 
of frying foods that a prejudice has arisen against it. But 
thin slices of potato, egg plant, and griddle cakes, and 
doughnuts may be made very palatable and digestible if 
fried quickly in a considerable quantity of hot fat, the food 
being in the pan a very few minutes. The trouble generally 
is that a small quantity of fat is used, and the cooking is 
continued until the fat is scorched, or until it has soaked 
into the food, and has become cold. How many pasty- 
featured persons we have seen who live on food prepared 
in that way! 
The chemistry of cooking is one of the most fundamental 
matters in practical living. Let us hasten the day of “home 
economics” and “domestic science,” whether we continue to 
have home cooking, or instead have professional cooks who 
make an art of their work. CHAPTER XXXII 
EXTRAS 
Tea and Coffee. In the menus given in Chapter XXX 
you will recall the fact that tea and coffee and cocoa were 
not included, but that a substitute, a cereal coffee, was 
mentioned. This was done on the basis of the belief that 
at least by young persons tea and coffee should not be used. 
A fuller explanation is due you. 
Tea and coffee, in spite of the differences in appearance 
and taste, are almost identical in the chemical properties 
and in their physiological action. The chief substance of tea 
is called theine; in coffee the same principle is called caffeine. 
In both tea and coffee there is also tannic acid. When either 
is boiled the tannic acid is extracted. The action of this 
substance is to hinder digestion and directly to injure the 
mucous membrane of the stomach. The taste of tannin 
may be noticed when drinking tea that has been allowed to 
boil vigorously for some time. It is bitter and astringent. 
Caffeine and theine are powerful stimulants of the nervous 
system, and of the heart to a less extent. 
Authorities agree that tea and coffee properly prepared, 
being as free of tannin as possible, and used in moderation, 
are probably not injurious to persons in normal health who 
are not given to other unhygienic habits. Practically, 
this means that you can endure them. But it is also to be 
understood that neither does one any good, except as stim- 
ulants of other sorts do one good in an emergency. Persons 
who are nervous or have poor digestion might better try the 
substitute cereal coffee, or simply hot water, if they feel 
the need of a warm liquid. Many persons drink strong 
coffee to keep them awake for an Unusual task. This is 
368 THE NEFARIOUS SODA FOUNTAIN 
369 
very foolish, and scarcely less foolish is the growing social 
custom in America of taking “afternoon tea.” One is liable 
to drink more tea than is good for him. If you are drinking 
tea for social purposes, it is much like eating for social pur- 
poses. If you want to be very sociable, logically you must 
keep on eating and drinking as long as anyone else does. 
Really, such a practice is very foolish. 
Cocoa and Chocolate. Cocoa and chocolate are being 
increasingly used as methods of preparing these products 
of the cocoa bean are improved. Chocolate is generally 
used in candies, and cocoa as a beverage. Both materials 
are rich in protein, fat, and carbohydrates, but it is only 
when consumed in solid form that much nutriment is ob- 
tained from them. The active principle is called theobromin, 
and has the same general effect as theine. Except for the 
active principle, which has a mild stimulating effect on the 
nervous system, chocolate and cocoa are valuable only when 
used as condensed foods, although condensed foods them- 
selves are not as useful as foods having greater bulk. This 
is because the small and the large intestines must be kept 
busy to create healthy conditions. 
The Nefarious Soda Fountain. The soda fountain and 
its accessories furnish a long list of “extras.” There is of 
course a definite craving for the products of the place, even 
when sociability is not an object. Lemonade and orange 
juice relieve thirst, although not so effectively as water. 
They also have beneficial effects on the operations of the 
kidneys. Beyond these two the ingenuity of the trade has 
put forth a great variety of extremely sweet concoctions, 
which not only do not relieve thirst, but they even prevent 
the normal coming of the appetite by the introduction of 
sugars which lead to fermentation developing in the stomach 
and intestine. 370 
EXTRAS 
There is a strong tendency toward the development of 
a vicious soda-fountain habit among our young people. 
Interference with normal digestion is almost sure to result, 
and a foolish habit of excess is fastened on one. If a person 
has enough nourishing food, the chances are that he will 
be less likely to be a frequenter of the palaces of marble 
slabs and nickel fixtures. CHAPTER XXXIII 
THE ORGANS OF DIGESTION, AND WHAT GOES 
ON IN THEM 
The Organs as Parts of a System. Like other systems 
in the structure of our bodies, the digestive system is com- 
plete in itself, but yet definitely connected with other sys- 
tems. In this fact the system of organs in the body make 
up a unit being. This, of course, is the point of iEsop’s fable 
of the Stomach and the Limbs. 
In the order of their occurrence the organs of the digestive 
system (Fig. 188) are the mouth, the tongue, the teeth, the 
gullet, the stomach, the small intestine, the large intestine, 
and the rectum. Organs that belong to the digestive system 
and act as secreting organs for the production of digestive 
fluids are certain glands. The best known of these are the 
liver, the salivary glands, and the pancreas. The products of 
these glands empty into the continuous tube at definite 
points, and have certain actions upon the food passing along. 
Other glands microscopic in size, lie in the walls of the 
stomach, in the small intestine, and in the large intestine. 
Looking into One’s own Mouth. A study of the mouth 
may be made before your mirror. Incidentally, you may 
learn some things you have never noticed before, and you 
may be reminded of the teeth that need the attention of 
the brush, and of the dentist. And the brown color of your 
tongue may be the sign that your digestion is at fault. The 
reason may be that your teeth have not been looked after 
for a long time. Persons of high-school age should have 
371 372 
THE ORGANS OF DIGESTION 
twenty-eight teeth. A little later, from eighteen on there 
will be four more, the “wisdom” teeth. 
If the additional four do not make their appearance near 
Fig. 188. Digestive System of Man. 
(From Weidersheim: Grundriss der verg. Anatomie.) 
the age of eighteen, you need not think Nature has cheated 
you, for the tendency in the white race is for the wisdom 
teeth to become smaller from generation to generation. In MISTREATED TEETH 
373 
many persons they never appear above the gums at all. But 
if you have lost any of the eight incisors (Fig. 189), or the 
four canines, or the eight premolars, or the eight molars, or 
indeed if you lose them before you are forty, then you will 
have committed a physiological crime. 
Mistreated Teeth. The author often spends his summers 
in a part of New York State where the country people have 
a curious way of taking it for granted that by the time one 
Showing milk teeth and beginning of permanent set. (From Flint: 
Human Physiology; Longmans, Green Co.) 
Fig. 189. Upper and Lower Jaws of Child. 
is thirty-five, he will have lost practically all his adult teeth. 
So, if you ask the age of a woman there, you may receive 
the reply, “Well, she’s got her teeth.” Interpreted, this 
means that she has bought her seemingly inevitable set of 374 
THE ORGANS OF DIGESTION 
false teeth. The combined causes of this condition of affairs 
is probably the perennial consumption of griddle cakes and 
ham, the neglect to eat vegetables containing mineral salts, 
especially lime, the failure to clean the teeth with a brush, 
and the ignorance of the need of having the tartar scraped 
from the teeth by a dentist. 
Far removed as the teeth seem to be from the processes 
in the stomach and in the intestine, they nevertheless receive 
their supply of nutriment from those organs, 
just as does any other part of the body. The 
teeth and the gums must be kept supplied 
with lime salts and with protein, and they 
must have exercise on hard foods. From a 
proper variety of foods the tissues have the 
chance to select what they need. When they 
are not given this chance they weaken. 
Knowing the Reasons. The author has 
found in his experience in teaching that young 
persons are more likely to do the proper 
things in the care of their health, if they 
know the reasons for the advice given them. 
But unfortunately you cannot afford to wait 
until you know the differences between 
alkalis and salts and acids before forming the 
habit of cleaning your teeth regularly and 
thoroughly. Nevertheless, the reason should be available. 
The thin hard coat over the exposed part of the teeth is 
called the enamel; the fangs are covered with a softer ma- 
terial called cement. Beneath both is the main part of the 
tooth, and this is called the dentine. At the center is the 
hollow space with its blood vessels and the nerve. 
If food material is allowed to remain between the teeth, 
it begins to decay under the action of bacteria which are 
always in the mouth. In the decay an acid is formed which 
Fig. 190. Ver- 
tical Section 
of Tooth. 
(From Weider- 
sheim: Grundriss 
der Verg. Ana- 
tomie.) KNOWING THE REASONS 
375 
n turn will dissolve a little of the enamel. This may keep 
ip until a hole has been formed through the enamel into the 
ientine. In the dentine the hole develops more rapidly, and 
before a neglectful person is aware of his condition a tooth- 
ache may be a final warning, in many cases a warning that 
monies too late to save the tooth. Brushing the teeth not 
sideways, but downward on the upper teeth inside and out- 
side, and upward on the lower teeth inside and outside, and 
back and forth on the crowns, should be done at least twice 
r day. A good and in- 
expensive tooth pow- 
ler is orris root and 
chalk. The general 
custom for those per- 
sons who look after 
their teeth at all is to 
brush them when they 
»o to bed, and soon 
after they arise in the 
morning. But if you 
have thoroughly 
cleaned the teeth at 
bedtime, then what 
have you to remove in 
the early morning? It 
appears that the frequent bad taste in the mouth on rising 
in the morning may have given the suggestion for cleaning 
the teeth then. Would it not be better to wash the mouth 
with warm water then, and after breakfast to clean them 
with the brush, and also with dental floss, if your teeth can- 
not be cleaned thoroughly with the brush? Try dental floss 
anyway after you have used the brush, winding the floss 
partly about the teeth that lie close together, and drawing 
back and forth close under the surface of the gums. You 
will find that thick, mucous deposits with tartar which the 
Positions for Holding the Brush 
Left Side of Jaw Right Side of Jaw 
Proper Direction of Brushing 
Fig. 191. Care of the Teeth. (Courtesy 
of American Museum of Natural History.) 376 
THE ORGANS OF DIGESTION 
brush does not reach have been cleared away, leaving the 
gums enlivened. 
Lurking Places of Trouble. Tartar is the hard limy 
material that may collect especially at the base of the crown 
of your lower incisors inside. It is poured out in liquid form 
with the saliva. Its formation does not mean that something 
is the matter with you. Some persons have more than others. 
It is this material which makes it necessary to have the teeth 
cleaned with a steel scraper at least once a year, or twice a 
year if the collection is large, for the tartar offers too good 
an opportunity for the acid of decayed food to work on the 
enamel. Besides, a large collection of tartar offers a breeding 
place for the bacteria of the dreadful Rigg’s disease or 
Pyorrhea, which causes teeth to become loose and to fall out. 
The bacteria that start here are often carried elsewhere by 
the lymph, producing serious troubles of many kinds. At 
the time of having the teeth scraped for tartar a good dentist 
will look for cavities. Ten to fifteen minutes given to filling 
a cavity at its beginning stage saves money and misery later. 
Never mind, it doesn’t hurt to have teeth scraped or to 
have small cavities filled. If you have a little brother or 
sister whose permanent set of teeth is about to come in, 
take a look at his or her back teeth. Every effort should be 
made to keep the back teeth especially of the milk set in 
place and sound, until the natural time for losing them comes, 
at six or seven years of age. Otherwise, the first permanent 
molars coming in just behind will slip into the places of the 
back milk teeth, with the result that the lower jaw will not 
be stimulated to grow long enough to give the face the proper 
form and the teeth regularity of alignment. The permanent 
teeth will come in just where their predecessors were, spaces 
between and all, only larger. But the spaces between per- 
manent teeth can be made more regular and the teeth set 
straighter when taken early by a good dentist. Have a THE TEETH AT WORK 
377 
thought for the youngsters, and they will have reason to 
thank you when they are old enough to realize how much 
you have done for them. 
“Dental Insurance.” A final word on the important 
subject of teeth should be given to the matter of having a 
good dentist. It is unfortunately too easy in most states 
for young men to obtain a diploma to practice dentistry. 
Public opinion is not yet exacting enough to demand the 
thorough preparation which is warranted by the importance 
of this work. Until it is, and indeed, as a direct means of 
developing a stronger public opinion on this question, one 
shoidd never encourage the liveried criers of dental companies 
who block the sidewalks in many of our large cities. Their 
masters should go into a more worthy business than preying 
upon the misfortunes of the rest of us. It may and probably 
will cost more to have the services of a dentist who has re- 
ceived thorough scientific training in one of our professional 
schools of high standing. But it is well to remember that 
each one of us has only one set of adult or permanent teeth. 
The effort to earn another dollar to pay for expert care and 
advice leading to the saving of our rare possession should 
be gladly made. A good dentist with pride in his work and 
in his profession will not advertise on the street corners. 
His office will be a model of neatness and order. His in- 
struments will be polished and sterilized, for some of the 
most loathsome diseases may be transmitted through the 
mucous membrane of the mouth. When a good dentist 
works at your teeth, a feeling of respect and confidence will 
come over you, for he handles his instruments with tender- 
ness and with skill, and with fingers that have been washed 
since the last person left the chair. With these suggestions 
you should know a good dentist from a quack. 
The Teeth at Work. The teeth do the first bit of work 
of the digestive system. Therefore, there must be enough 378 
THE ORGANS OF DIGESTION 
of them to engage every piece of food brought within their 
range. The gums around should not be tender; otherwise, 
the stimulus will be given to the tongue and the cheeks to 
shift the food to some other group of teeth. Have you ever 
noticed yourself doing this? With all the teeth in the best 
of condition they should attack bites of reasonable size, and 
reduce them to a condition approaching fluidity. You recall 
that Mr. Fletcher claims to be able to make every kind of 
food liquid. How long it would take one to do this with 
various kinds of food only a trial will tell. As a matter of 
fact, you always chew a mouthful many more times than 
you think you do. Only a few persons swallow their food as 
birds do. Chewing a mouthful twenty-five times is not 
unusual; some chew each mouthful more than that, and do 
not weary in well doing. 
The Tongue.— —The tongue is an organ with several 
functions or uses. You can distinguish two points as those 
of a pair of calipers closer together on the tip of the tongue 
than you can on any other part of the body. It is therefore 
a highly developed organ of touch. Doubtless we make a 
great deal of use of the tongue unconsciously in determining 
whether a piece of food has been chewed until it is small 
enough to be swallowed easily, and also in detecting hard 
things in soft food. Many babies dislike food mixtures of 
hard and soft particles, which they must distinguish by 
touch organs on the tongue and on the lining of the cheeks. 
The surface of the tongue is covered thickly with little 
prominences, called papilla:. In all of these are nerves coming 
up and branching into fine filaments. Some are touch 
papillae, and others are taste papillae; still others are tem- 
perature papillae, useful in distinguishing degrees of heat. 
Owing to the fact that the body of the tongue is muscular 
and firmly attached at one end, it is adapted to acting im- 
mediately in the interest of the whole body when information THE STOMACH 
379 
comes to it through any of the organs of sense. This action 
is manifested by pushing objectionable things out, or by 
shifting desired food under the teeth to be further masti- 
cated, or pushed back into the pharynx (Fig. 192) for sending 
down the gullet (Fig. 192). 
The tongue is also an organ of speech. Until you try to 
see what sounds you can make with the tongue lying motion- 
less and flaccid on the floor 
of the mouth, you can 
scarcely realize how much 
you depend upon it in 
speaking. A large part 
of the mobility and the 
beauty of the human voice 
come through the action 
of the tongue. 
The Pharynx. The 
pharynx mentioned in a 
previous section is not ex- 
clusively a part of the 
digestive system. It is 
the “cross-roads” of the 
digestive system and the 
respiratory or breathing 
system. The gullet is a 
narrow tube extending from the pharynx down to the stom- 
ach, and is about twelve inches long. It has no other 
organs connected with it, and the food passes rapidly 
through it. 
The Stomach. The organ most frequently located 
wrongly by persons who know little of anatomy is the stom- 
ach. A “stomach-ache” may be in the stomach, but it 
usually is in the small intestine. The customary way of 
Fig. 192. Diagram of the Pharynx. 
(From Weidersheim: Grundriss der verg. 
/inatomie.) 380 
THE ORGANS OF DIGESTION 
becoming acquainted with the stomach through its aches is 
misleading. If you feel at the lower end of the breast-bone, 
and note that this is about the halfway point of the trunk, 
you will not be far from a position just in front of the 
stomach. 
The human stomach is a large pouch with a capacity in 
the adult person of about three pints. The larger end of the 
pouch lies near the left side of the body. Near the end the 
Fig. 193. Stomach and Small Intestine. 
(From Hough & Sedgwick: The Human Mechanism; Ginn and Company.) 
gullet connects and carries the food to the recess formed 
at the large end. The curved, tapering stomach bends 
across toward the right side of the body, and at its end con- 
nects with the small intestine. 
The Small Intestine. The small intestine folds upon 
itself many times, disposing in this way of about twenty feet 
of length. The small intestine connects with the large in- THE DIGESTIVE GLANDS 
381 
testine very much as the stem of a corn-cob pipe connects 
with the bowl, by going in at the side near one end. Another 
resemblance in the comparison is to be noted in the fact 
that the large intestine starts upward just as the bowl of a 
pipe lies when in use. Imagine now a cone-shaped sac 
hanging by the base from under the bottom of the bowl, and 
you have the well-known, troublesome, and at the present, 
useless, vermiform appendix (Fig. 194). The large intestine 
extends upward on the 
right side and around to 
the rectum, a total length 
of five feet in a grown 
person. 
The Digestive Glands.— 
The digestive glands are 
located as follows: one 
pair of salivary glands in 
the muscles of the cheeks 
just in front of the ears, 
a second pair of salivary 
glands under the jaws 
near the hinges, a third 
pair of salivary glands 
under the base of the tongue. All these send their secre- 
tion into the mouth. You may find inside your cheek at 
about its center a little lump upon which the side salivary 
glands open. The liver lies over the stomach. Through the 
bile duct connection is made with the small intestine close 
to its beginning near the stomach. The pancreas, a soft, 
yellowish-brown gland, lies in the fold of the stomach and 
the first part of the intestine, and sends its connecting tube 
down to the intestine near the opening of the bile duct. In 
cattle and pigs the pancreas is called the stomach sweet- 
bread; it is by that name that butchers know the organ. 
Fig. 194. Vermiform Appendix. 1, ap- 
pendix; 2, small intestine; 3, large in- 
testine. (From Weidersheim: Der Bau 
des Menschen.) 382 
THE ORGANS OF DIGESTION 
Enzymes. It has already been intimated that long 
retention of the food in the mouth is one of the most impor- 
tant steps in the process of digestion. The mastication of 
the food prepares it for what comes after, no matter where 
the digestion is to take place. But for the digestion of 
starch it is immediately useful to have every part as small as 
it can be made, so that the digestive enzyme (a transforming 
chemical called ptyalin) in the saliva may reach it easily, 
but the masticated food should be kept there until it begins 
to taste sweet. This will be the sign that the beginning of 
the chemical transformation to sugar has been made. If the 
starch of oatmeal or bread or potato is swallowed before 
this change occurs it must pass through the stomach and 
into the intestine before it will again come under the in- 
fluence of an enzyme which can change it to sugar. The 
first step in efficient digestion is thorough mastication in 
the mouth of all kinds of food, no matter whether you can 
swallow it immediately or not. 
The Conditions of Digestive Action. The food passes 
not by dropping, but under the influence of waves of con- 
traction, through the gullet into the stomach. Even before 
the food has reached the stomach, connecting nerves have 
caused the glands in the walls of the stomach to secrete the 
gastric fluid. Of course we are not conscious of this as 
we are conscious of our mouth “watering” on seeing or 
even thinking of something good to eat; but the stomach 
“waters,” too. The saliva being alkaline in reaction 
stimulates the gastric glands still further to pour out their 
fluid. Gastric fluid is ninety-nine and one-half per cent 
water, but in the remainder there is two-tenths of one per 
cent of hydrochloric acid, and two important enzymes, 
pepsin and rennin. The acid changes the contents of the 
stomach from its alkaline condition to an acid one. The 
two enzymes begin to act upon the protein in the stomach THE CONDITIONS OF DIGESTIVE ACTION 
383 
contents. They have no effect upon the starch, or upon 
the fat. 
When food is taken without appetite, the.preliminary flow 
of digestive fluids does not occur, and digestion is more 
difficult in consequence. These fluids are not secreted well 
under conditions of worry and vexation. Children ought if 
possible to be prevented from crying at the table, for anger 
and fear dry up the mouth, and the stomach also. The nor- 
mal wave-like contractions of the stomach do not take place 
when the person is under the influence of strong emotions 
from any cause. This has been learned by observations 
made on cats through the aid of X-ray pictures by Professor 
W. B. Cannon, of Harvard University. We have good 
reason for believing that similar things happen in the stomach 
of human beings. Nervous persons often complain of a 
feeling of heaviness in the stomach. This is probably due 
to the stagnation of the contents of the stomach. As Pro- 
fessor Cannon has written, “Neither scolding parents nor 
snarling children facilitate the digestion of a Christmas 
dinner.” One might add, “Neither can one long retain 
normal health if he frequents noisy restaurants where dishes 
are clattering, where orders are bawled out, or where loud 
orchestras and talking almost as loud collectively or severally 
keep one’s nerves in a state of irritated tension.” 
After two or three hours under normal conditions and 
with good mastication the stomach contents are reduced to 
a completely liquid condition, and the stomach by periodic 
waves of contraction in the tapering portion of the stom- 
ach has forced the food out through the “gate” of the 
stomach into the intestine. If any hard particles re- 
main, they are turned back again and again from the 
gate until they are changed to small bits. If this cannot 
be done in the usual time, an hour or two more may be 
given by the overworked stomach, but after that the stom- 
ach throws off its undeserved burden. You feel very ill 384 
THE ORGANS OF DIGESTION 
for awhile, but you have learned a lesson which ought not 
to go unheeded. 
Some persons cannot digest certain foods, or foods in 
certain combinations. You learn by experience what your 
stomach can do. Sometimes one is troubled with a “greasy” 
feeling coming up from the stomach, or with “belching.” 
These troubles are due to the production of gas in the stom- 
ach by bacteria which are causing fermentation and the 
decay of food. If the food is thoroughly masticated, and 
is not taken in too large quantities, and if one lives a healthy 
life with enough exercise, troubles of this kind are not likely 
to appear. 
From the Stomach to the Small Intestine. During 
the process of digestion in the stomach the contractile ring 
of muscle at the lower end of the stomach relaxes every five 
minutes, and the gate is open, permitting a small quantity 
of liquid and partially digested food to pass into the intestine. 
Here the nutrients of all kinds, the proteins, the carbohy- 
drates, and the fats, sustain their greatest changes. 
The first effect upon the food coming into the intestine 
is a change from the acid condition of the stomach to an 
alkaline condition. This alkali, sodium carbonate by name, 
is produced by the intestinal glands which occur thickly set 
along the entire course of the small intestine, and tends to 
counteract not only the acid coming from the stomach, but 
also the acids formed in the intestine by the decomposition 
caused by bacteria that are always present in varying quanti- 
ties, more in unhygienic eating, fewer in healthful living. 
What the Enzymes Do. The pancreas sends its secretion, 
also strongly alkaline, into the intestine near its union with 
the stomach. The secretion contains three different enzymes. 
One is called trypsin. This enzyme is important in com- 
pleting the digestion of the proteins, breaking up the mole- WHAT THE ENZYMES DO 
385 
cules, carrying them through steps of chemical change that 
are very complicated, and finally bringing them into a con- 
dition where the molecules are small and are known as 
peptones. Another enzyme is amylopsin. This one is very 
much like the ptyalin of the saliva, for its work is changing 
the starch to sugar. The third enzyme from the pancreas 
is called lipase or steapsin. Its action is to break up the 
molecules of fat into what are called fatty acids and glycerin. 
The appearance and nature of digested fat is largely that of 
fluid soap. 
The liver sends its secretion into the gall bladder, and from 
there it passes by the bile duct into the intestine near the 
opening of the pancreatic duct. The bile does not contain 
an enzyme. The contents of the bile are in a measure 
waste products of the liver, but experiments have proved 
that if the bile does not flow naturally into the intestine 
over half of the fat eaten cannot be used by the body at all. 
The enzymes from microscopic glands of the wall of the 
small intestine which act upon carbohydrates there are 
called sucrase, maltase, and. lactase. Erepsin from a similar 
source acts upon protein. 
When food in the stomach has passed through the alkaline 
or neutral conditions, and is mixed with gastric fluid, the 
proteins begin to be digested. In detail, the process is as 
follows: the hydrochloric acid in the gastric juue converts 
the proteins of the food into meta-protein or syntonin which 
in turn is transformed by the enzyme pepsin into proteoses, 
and finally into peptones, in which form absorption occurs. 
In the small intestine the proteins are acted upon by another 
important enzyme trypsin, from the pancreatic juice. In 
an alkaline solution this enzyme changes protein to proteoses. 
These further change to peptones. From this stage change 
continues through the combined action of trypsin and erepsin 
into the compounds called amino-acids. Of course, we 
realize that the chief value of the information contained in 386 
THE ORGANS OF DIGESTION 
this paragraph so far as young students are concerned is 
that it indicates the great complexity of the chemical trans- 
formation of protein in digestion. As a matter of fact, no 
one who is not a chemist with expert knowledge of the 
organic branch of his science has a very definite under- 
standing of what such terms as “amino-acid” and “pro- 
teoses” really mean. Nevertheless, the description of the 
main features of the digestion of protein are given here for 
the sake of completeness. 
During the process of digestion in the small intestine, the 
contents of the cavity are being slowly pushed along by a 
series of wave-like contractions occurring at considerable 
intervals. Between these intervals, and related to the out- 
pourings of food from the gate of the stomach, the intestine 
becomes segmented by muscular contraction here and there 
over and over again, thus providing for the repeated shifting 
of the contents and their thorough mixing for complete 
digestion. Finally, the undigested portions of the food are 
pushed out into the large intestine. But the probability is 
that the small intestine is never empty except when fasting 
is prolonged beyond the usual period. 
Appendicitis. There was a time, as people began first to 
hear of a new disease called appendicitis, when it was thought 
one should not swallow grape seeds or other small hard ob- 
jects that might not digest. There is no reason for swallow- 
ing undigestible things, but, if swallowed, they do not cause 
appendicitis. The real cause of this disease is to be found in 
the lack of normal and healthy activity of the large intestine. 
Riding, running, rowing, rapid walking, baseball, basket ball, 
captain ball, football, as well as more generally productive 
activities, such as sawing and chopping wood, hoeing the 
garden, pitching hay, plowing corn, and running after little 
brothers and sisters, are all preventives not only of ap- 
pendicitis, but also of other dangerous or debilitating con- THE LARGE INTESTINE 
387 
ditions of the large intestine. Incidentally, you should know 
that the vermiform appendix is a small organ which has 
slight use in the human anatomy, but in the lower animals 
such as the rabbit and the squirrel, it is large, and aids 
materially in the digestion of food. Being reduced in size 
and degenerate in man, it is liable to be closed up by becom- 
ing inflamed. In this condition the blood does not circulate 
normally. If massage does not reduce the inflammation, 
decomposition of the appendix may set in. In extreme cases 
an operation must be performed and the appendix removed. 
If ever you feel a sharp, “doubling-up” pain, continuing 
for a long time in the abdominal cavity near the groin of 
the right side, you should speak to your parents about it, 
and suggest that you be permitted to visit the doctor. If 
the pain is very severe, the doctor should be called at once. 
Putting the matter off as a case of “indigestion” may be 
dangerous. It is quite likely that deaths from “bowel com- 
plaint,” as described by doctors of former generations, was 
really due to appendicitis. 
The Large Intestine. The large intestine appears to be 
a long way from the head, but nerves connect them. The 
headache proves it. The large intestine receives and some- 
times holds for too long a time a considerable quantity of 
undigestible and undigested materials, setting up the con- 
dition known as constipation. Except for a small amount 
of digestion and absorption going on in the large intestine 
the main thing that should happen to the contents is for 
them to pass along and out of the body as regularly and as 
completely as possible. When this work is slow or is im- 
peded, bacteria will cause decay in the material, creating 
poisons which are absorbed by the blood, finally acting upon 
the nerves, and resulting in headaches and general lassitude. 
Constipation tablets and other laxatives are not of permanent 
value, although they may give temporary relief. 388 
THE ORGANS OF DIGESTION 
Large, vigorous movements of the trunk, especially before 
breakfast, are useful in cases of constipation. Oftentimes 
one is benefited by eating freely of fresh fruits and of bran 
muffins. The latter especially stimulates to activity the mu- 
cous lining of the intestine. Two glasses of water drunk be- 
fore breakfast also is a help. A great deal of water taken even 
at meals is now known to be in line with healthful living, pro- 
vided the water is not used to facilitate the gulping of food. 
Glands 
Villi 
Long'l 
Circular 
Submucous 
Coat 
Mucous Coat 
Muscular Goat 
Fig. 195. Section of Small Intestine. 
(From Hough & Sedgwick: The Human Mechanism; Ginn and Company.) 
If careful attention to diet and a generous amount of exer- 
cise will not cure the scourge of constipation, then the help 
of a physician should be enlisted. 
Absorption. The question must already have arisen 
in your mind, “ What happens to the food that is changed to 
glocuse sugar, peptones or amino-acids, and fatty acids and 
glycerin through all these processes in the intestine?” The 
answer is to be found not only in the general reduction of 
the quantity of material in the intestine, but also in what 
takes place in the organs lining the intestine which are con- 
cerned with its removal. These organs are the villi (Fig. 195). 
They are microscopic, finger-shaped filaments extending out ABSORPTION 
389 
from the interior wall a short distance into the cavity. They 
increase the surface of the interior many times. The villi 
are the absorbing organs of the intestine. The nutrients pass 
into the cells of the villi, and into the blood vessels, or into 
the lymph vessels, by what is called the process of osmosis. In 
the process of osmosis liquids separated by a permeable mem- 
brane tend to pass through and mingle with the liquid on the 
other side. They do this readily if the particles in solution 
are small enough, and if there is a physical attraction be- 
tween the materials separated. 
In the blood protein products begin the process of becom- 
ing proteins again; the fatty acids and the glycerin are 
made into fats, but the glucose sugar is not changed at all. CHAPTER XXXIV 
TIIE CIRCULATORY SYSTEM 
Your Own Circulatory System Under Examination. 
Before we can follow the course of the absorbed products 
of digestion through their many changes to their destina- 
tions, it is necessary to understand the structure and the con- 
nections of the circulatory system which transports these 
products. We shall begin 
by studying the food 
transportation system at 
a point easy of access. 
If you separate your 
jaws slightly, and place 
the tip of the middle fin- 
ger in the hollow space 
just in front of your ear, 
you will obtain proof that 
the silent little “engine” 
at the center of your chest 
is working. Press ever so lightly, and you will receive a 
suggestion as to whether the pumping is strong, regular, and 
healthy. Take your watch, and count for one minute the 
beats or pulsations, and you will know what is the number 
of heart beats for you, in your present state of health, and 
position of body. The number will not be the same that 
you may have heard is definite for all human beings, but it 
will be correct for you, if you are in good health. In other 
healthy persons the number will probably be a little different. 
The blood that is passing in the vessel you are examining 
is on its way to your brain and scalp. If you have the curi- 
Fig. 196. Finger on the Pulse. 
390 THE OPERATION OF TIIE HEART 
391 
osity to know more about the pulse, ask some one to test 
your pulse in the same place while you are asleep, and do 
it yourself again after a hard run. Of course, you will dis- 
cover some variation in the number of beats, and also in the 
force of the beats. 
While you have been experimenting, your entire supply 
of blood, perhaps a little over ten pints (twelve to fourteen 
in an adult) has been coursing through your arteries and then 
through your veins many times. As a matter of fact it re- 
quires but half a minute for all the blood in the human body 
to leave the heart, pass through the most extensive part of 
the blood system and return to the heart again. This repre- 
sents a great total weight of blood carried in a day and a 
great store of energy to keep the little engine going. And 
yet, it is not altogether correct to speak of the heart as an en- 
gine, unless we think of it as a pumping engine. 
The Operation of the Heart. The study of the working 
of the heart shows that the power manifested in the contrac- 
tion of its muscular tissue, under the control of a fine adjust- 
ment of involuntary nerves, is making a double force pump 
operate as perfectly as could be. These two pumps lying 
side by side and separated only by a dividing wall, look like 
one organ from the outside, but examination shows the heart 
to be composed of two quite distinct pumps. Each pump 
is made up of two chambers; the upper chambers are called 
auricles, and the lower ones ventricles. The upper chamber 
on the right side is a receiving chamber for the blood that 
comes back to the heart from the body in general. The 
lower chamber receives the blood from the upper chamber. 
From the right lower chamber the blood is forced out to the 
lungs; from the left lower chamber the blood is forced to the 
organs of the body generally. 
The auricle of the right side receives blood from the dis- 
tant organs of the body, in fact, from all the organs except 392 
THE CIRCULATORY SYSTEM 
from the lungs. The blood 
in the receiving chamber 
flows down into the pump- 
ing chamber; the pumping 
chamber feels the stimulus 
of the presence of blood, 
contracts its muscular 
walls, closes up the gate- 
way by which the blood 
entered, and the blood 
flows strongly out through 
an artery to the lungs for 
as far as the 
carbon-dioxide waste is 
concerned. After passing 
through fine vessels called 
capillaries, because they 
are fine like hair (Latin, 
capilla, hair), the blood 
comes back from the lungs 
to the receiving chamber, 
the left auricle, of the left 
pump. Again the blood 
flows through the opening 
into the lower chamber, 
the lower chamber now 
contracts and by means of 
thicker, heavier muscles 
than lie in the ventricle of 
the right pump forces the 
collected blood into the 
great artery (called aorta) 
of the general body system. 
From the branches of the 
great aorta, the blood passes 
Fig. 197. Heart and Organs of Circu- 
lation. L, lungs; M, mesentery; P, liver. 
(From Hough and Sedgwick: The Hu- 
man Mechanism; Ginn and Company.) THE COMPOSITION OF THE BLOOD 
393 
around and through the muscles, the bones, the nerves 
and brain, the liver, stomach, small and large intestines, 
kidneys, to go through another system of capillaries, and then 
into the veins. The veins have thinner walls than the arter- 
ies. They unite into larger and larger vessels from the ex- 
terior organs and the internal parts, and finally come to form 
the large trunk vein, the inferior vena cava (Fig. 175) running 
parallel with the aorta along the body cavity near the back- 
bone. Branches from the arms and the head unite to form 
the superior vena cava (Fig. 175,G). Both veins unite at the 
heart, and pour their contents into the right auricle. To say 
that all this complicated and circuitous route can be passed 
over in thirty seconds seems unbelievable, but it is true. 
The Meaning of the Circulatory System. It is obvious 
that the highly complex and vigorous circulatory system 
could scarcely have been developed in man without there 
being some fundamental need for it. Naturally, the mech- 
anism is not an end in itself, but it is a means to an end. The 
end is getting the digested nutrients distributed to the vast 
multitudes of body cells where they are needed. 
If you were examining a railway system for the first time, 
your interest would be not only in the tracks, the “ cuts and 
fills,” and the country round about, but you would have an 
interest in locomotives and the vehicles for transportation. 
So we shall give a little attention to the parts of the blood 
system that do the carrying, since we know already what is 
to be carried. 
The Composition of the Blood. If some one of your class 
desires to sacrifice himself for the common good, a needle can 
be sterilized over a gas flame or a lamp flame, wiped on a 
bit of sterilized gauze or absorbent cotton, and thrust quickly 
into the tip of a willing finger. You may thus obtain a drop 
of blood which you can apply to a glass slide and prepare for 394 
THE CIRCULATORY SYSTEM 
use on the stage of a compound microscope. Of course, you 
will be surprised to see that the blood is not red at all, but 
yellow. This is because the tiny red blood corpuscles are 
partially transparent. It is important to know that these 
biconcave plates contain a substance called haemoglobin, 
which has the power of combining with oxygen where it meets 
it in abundance as in the lungs, and giving up the oxygen 
where free oxygen is lack- 
ing, as in the tissues. 
But the red corpuscles 
will not give the flush of 
youth and vigor to your 
cheeks, or vitality to your 
whole body, unless these 
same corpuscles have 
enough of iron in them. 
Look up chapters on 
foods, or recall the 
sources of iron in foods. 
In the drop of blood 
you have collected there 
may be one or two pale, 
white irregular bodies, a 
trifle larger than the red 
corpuscles. These are called the white blood corpuscles. 
They have many uses, but one of the most famous is the ac- 
tivity of these corpuscles as eaters of other cells. The tech- 
nical term for that kind of cell is 'phagocyte, which is Greek 
for “a cell that eats.” As a rule the things eaten by phag- 
ocytes are bacteria. You may see white corpuscles that 
have collected in great numbers as a faint ring about a small 
splinter in your hand. The white corpuscles wander through 
the tissues, being able to pass through the walls of blood 
vessels, which red corpuscles cannot do, and collect about an 
infected region where bacteria are sure to be. These bacteria 
Fig. 198. Red and White Blood Cor- 
puscles. (From Hough & Sedgwick: 
The Human Mechanism; Ginn and Com- 
pany.) THE LYMPH SYSTEM 
395 
are the natural prey of the phagocytes, and have been ob- 
served under the highest powers of the microscope actually 
in the protoplasm of the phagocyte. Prof. Elie Metschni- 
koff, the late Director of the Pasteur Institute of Paris, 
studied and wrote much concerning these white cells that 
act very much as if they were creatures within creatures, 
capturing our disease enemies, and no doubt often saving 
us from affliction without our being any the wiser. 
That part of the blood which does all the work of trans- 
porting the food is the liquid portion, called the plasma. 
This is ninety parts water and ten parts solid. Part of the 
solid manifests itself when blood clots. If you separate it 
from the red corpuscles, you will have a large quantity of 
tough yellow fibers, called fibrinogen. The general color of 
the plasma is pale yellow, as may be seen when blood stands 
for a few hours. The clot and most of the red corpuscles 
will be in a mass, and the plasma will show as the pale, yel- 
low serum. 
It has already been stated that the arteries divide into 
smaller and smaller branches, finally reaching and carrying 
blood to every little group of living cells in the body. In their 
ultimate branches the arteries pass over into the finer 
branches of the veins, forming thereby the connecting capil- 
laries. Since there are organs to be supplied with blood that 
are near great arterial trunk lines, there are sets of capillaries 
in all these organs. Capillaries are not necessarily far away 
from the heart. 
The Lymph System. The walls of the capillaries are 
thin, being adapted therefore to the easy passage of fluid 
back and forth between blood vessels and cells. If it were 
not for this fact the food flowing swiftly about in the blood 
system would keep on flowing along the same track. Al- 
though the cells are very small, there are nevertheless spaces 
between them. These spaces are connected with one another 396 
THE CIRCULATORY SYSTEM 
in a vague and extremely irregular system. The spaces are 
called lymph spaces, and the system they make is called the 
lymjph system. Lymph is very much like blood with the red 
corpuscles left out, but its condition may vary considerably, 
due to the abundance or scarcity of food or waste. 
When the food in solution begins to make its way by osmo- 
sis through the walls of the capillaries, it may go into an 
adjacent cell that needs it, or 
it may flow about the cells and 
on to other cells in the vicinity. 
Finally, it may pass into the 
lymph spaces and thus into 
that system. In case the liquid 
food passes into a cell it would 
possibly undergo changes which 
will be discussed presently, 
and there might come out from 
the cell some of the waste of 
the cell. This waste would pass 
into the lymph spaces, or it 
might go into the capillaries. 
If the waste goes into the 
lymph spaces, it is carried on in 
a sluggish stream into large and 
still larger tubes until a trunk 
(a large conducting vessel) has 
been reached. There are two 
of these in the body, one from 
the lower portion of the body 
and the legs, and a branch of it from the left arm and side of 
head. The other important trunk line of the lymph system 
comes from the right side of the body and the head. Both 
pass to the nearest large vein close to the point where the 
veins enter the two auricles of the heart. There each pours 
its contents into the veins, and the veins quickly deliver their 
Fig. 199. Portion of the Lymph 
System. (From Hough & Sedg- 
wick: The Human Mechanism; 
Ginn and Company.) THE LYMPH SYSTEM 
397 
burden into the auricles of the heart. At those points, 
and in a considerable 
part of the large blood 
vessels leading from the 
heart, the lymph and 
the blood are mixed. 
It is apparent that the 
lymph is supplied from 
the capillaries in large 
part, but in the course 
of lymph vessels there 
are large lymph glands 
where white blood cor- 
puscles are made, and 
often where impurities 
are attacked and dis- 
posed of. You may 
find the little masses 
or lumps of lymph glands made in the arm-pit, and also in 
the groin of the leg. 
Fig. 200. Exchange of Oxygen and Car- 
bon Dioxide Between Capillaries and 
Lymph Spaces. (From Hough & Sedg- 
wick: The Human Mechanism; Ginn and 
Company.) CHAPTER XXXV 
THE DESTINATION OF THE INCOME AND THE 
OUTGO OF LIVING 
The Transportation, the Storing, and the Oxidation of 
Food. At the end of Chapter XXXII we left the three 
organic nutrients as liquefied proteins, fats and carbohydrates 
embarked on their swift journey through the dark and 
circuitous passages of our bodies. They have been changed 
in the process of digestion, but they are back again in their 
own chemical form although entirely separated from physical 
combination with other nutrients. 
The first stage of the journey is very short. All the blood 
vessels that collect from the small intestine, the stomach and 
the large intestine carry blood and its burden through the 
'portal vein (Fig. 197) to the liver. In the liver the portal 
vein branches into numerous capillaries. Through the walls 
of these capillaries most of the glucose passes out and is 
taken up by the cells of the liver and is immediately changed 
to a material resembling sugar but called glycogen. After a 
heavy meal the liver may contain as much as 10 per cent 
of its weight in glycogen. The glycogen is stored in the liver 
cells only a short time, generally being doled out and changed 
meanwhile to glucose again, and sent along its journey before 
the next meal. The glucose that is stored in the liver is likely 
to be carried farther and stored as glycogen in the muscles. 
While the glucose is in the blood, and as it passes through 
muscular tissue in the internal organs and elsewhere, oxida- 
tion takes place between the glucose and the oxygen that is 
carried by the red blood corpuscles. Thus a ready supply 
of energy for work is afforded. Incidentally, the muscular 
398 TR AN SPORT ATION AND OXIDATION OF FOOD 
399 
energy is transformed into heat energy which gradually, and 
in health regularly, passes off from the body as waste. Also 
the products of oxidation, carbon-dioxide and water, are 
ultimately given off by organs of excretion, the lungs, the 
kidneys, and the skin. When carbohydrates are eaten in 
greater quantity than the body requires, the surplus tends 
to be converted into fat. A person cannot tell except by an 
experiment in eating known quantities of carbohydrates, and 
by weighing himself periodically, just how much carbohy- 
Fig. 201. Paths for Products of Digestion. 
(From Hough & Sedgwick: The Human Mechanism; Ginn and Company.) 
drates his own body does require or could use without be- 
coming fat. The weight of an adult should be constant. 
The weight of an adolescent should not vary greatly from 
the rate of increase indicated by the table on page 195. 
It was stated in Chapter XXXIII that during the passage 
of the fatty acid and the glycerin or glycerol through the intes- 
tine wall they recombine into fat. This result is due to a 
peculiar reversing action of the enzyme lipase which is known 
to have the power of digesting fat. The absorption of fat is 
carried on by the lymph vessels in the villi of the intestine 
(Fig. 195) rather than by the capillary blood vessels. It is the 
presence of large quantities of fat droplets in the lymph ves- 
sels near the small intestine that gives to these vessels their 
milk-like appearance; hence their name lacteals (Latin lac, 400 
INCOME AND OUTGO OF LIVING 
milk). Fat is deposited as droplets in the cells of the body, 
or it may be oxidized as fuel in the blood. 
The absorbed products of protein digestion on passing 
into the blood begin to rebuild their chemical structure, 
which is not completed until the cells are reached. Experi- 
ments indicate that absorbed proteins become available at 
once for fuel as well as available later for their especial func- 
tion of cell formation and repair. To some extent proteins 
which have been digested and absorbed are transformed in 
the body into carbohydrates and fats. 
End-Products in Digestion. As the result of the oxidation 
of protein compounds in the body carbon dioxide, water, and 
certain “ end-products ” are made. The chief element of these 
end-products is nitrogen, and the most of them are formed 
through a maze of chemical changes occurring to some extent 
throughout the body, but chiefly in the liver. There some 
simple end-products are combined to form urea. Uric acid 
and creatinin are other end-products occurring in the urine. 
The Loss and the Repair of Protein. In the human 
body two and one-half parts out of one thousand of its pro- 
tein are used up daily. But this loss takes place without 
relation to whether wre work hard or sit still. It is due to 
the “wear and tear” of the machinery of the cells in opera- 
tion. Wherever the cells are that need repair or wherever 
the addition of new cells may take place, there are certain 
protein-containing foods which, each one of itself, will supply 
the various protein needs of the body. These are such foods 
as meat, eggs, fish, milk, and cheese. They are called com- 
plete or perfect proteins because of their adaptability to all 
situations where protein is needed. When digested each of 
these foods may be broken up chemically into seventeen dif- 
ferent parts. These several parts pass into the blood, and 
while they are on their way to the cells are reconstructed by THE STRUCTURE OF THE LUNGS 
401 
stages and in different groupings, the final stage occurring 
in the cell destinations where the protein is of course different 
in the various kinds of tissues. Thus, from the same milk 
or eggs protein may be produced exactly like the protein of 
muscle cells, brain cells, or liver cells. 
The Chief Sources of Energy. At the same time that 
our bodies are building up their tissues they are also tearing 
down tissues. But the production of waste does not always 
imply that a process wholly destructive in nature has been 
in operation, for when glucose or fat is oxidized, and carbon 
dioxide and water are produced as wastes, the energy set 
free is manifestly of great value to the working body. There 
are three sets of organs by means of which wastes are ex- 
creted, the lungs, the kidneys, and the skin. Besides being 
organs of excretion, the lungs also take in the important 
element, oxygen. 
The Structure and Connections of the Lungs. The 
lungs (Fig. 202) are two large, spongy-walled sacs occupying 
the greater portion of the chest cavity. They lie to the 
right and left of the heart, and connect near their upper 
ends by two bronchial tubes to the windpipe (Figs. 202, 3). 
The windpipe connects at the top with the larynx or voice 
box and opens by a slit-like passageway into the pharynx. 
The lungs lie like two expanded balloons within the chest 
cavity, for the gases are inside, and there is no air between 
the lungs and the wall of the chest. 
Near the bronchial tubes each lung is supplied with a 
large artery and a large vein. Branches extend to the small- 
est air-sac, and form capillaries there. We learned in Chap- 
ter XXXIV that the venous blood returning to the heart 
from the extremities and from the digestive organs in the 
trunk passes from the heart by the right ventricle to the 
lungs. Thus, through the pulmonary artery comes the 402 
INCOME AND OUTGO OF LIVING 
blood that has been collecting wastes which the lungs may 
give off. 
The Waste Excreted by the Lungs.——Carbon-dioxide 
is the waste given off exclusively by the lungs. It is carried 
to the lungs in the blood plasma and excreted from the 
capillaries into the smallest spaces in the lungs, and forced 
out in the act of expiration. Water is excreted in the same 
way by the lungs in 
considerable quantity 
in the form of vapor. 
The presence of water 
in the expired breath 
may be shown by 
blowing the breath 
against a mirror. Heat 
also is given off by 
the lungs noticeably. 
The great extent of 
surface within the 
walls of the lungs 
makes possible the ex- 
cretion of the quantities of heat, water, and carbon-dioxide 
which go out from these organs. 
For a long time it has been thought that carbon-dioxide 
is a poison. Recent experiments have failed to show that 
this waste is poisonous, or that the odor characteristic of an 
ill-ventilated room is poisonous. The cause of discomfort 
in a “close” room seems to be connected with the amount 
of heat in the surrounding air and with the ability of the 
body to free itself of its own heat. This matter will be taken 
up in some detail on page 407. 
The Structure and Connections of the Kidneys. Down 
in the “small” of the back, lying within the abdominal 
cavity against the muscles of the back, on either side of the 
Fig. 202. The Lungs. (From Flint: Human 
Physiology; Longmans, Green Co.) THE STRUCTURE OF THE KIDNEYS 
403 
spinal column are the two kidneys (Fig. 203). Two branches 
from the aorta extend to the kidneys and there divide 
into numerous capillaries. At a great number of points 
in the muscular tissue of the kidneys the capillaries turn 
on themselves in several loops forming the centers of 
microscopic masses. Fitting closely around each of these 
loops of capillaries is an inner wall of a double-walled sac 
(Fig. 203). The outer wall of 
this sac forms the boundary of 
what is called a renal corpuscle 
(Fig. 204), and connects wit! 
the slender kidney tubule (Fig, 
204). The tubules join with 
others into large and still largei 
tubes and ultimately conned 
with the ureter (F’ig. 203), om 
of which passes from each kid- 
ney to the bladder (Fig. 203), 
Since only a portion of the 
protein waste may pass 
through the kidneys in one cir- 
cuit of the blood, the body is 
never free of protein waste, 
But when a person eats toe 
much protein his body is liable 
to contain a elangerously large 
amount of the poisonous pro- 
tein waste. When through excessive eating or through the 
elrinking of alcoholic liquors the active cells of the kidneys 
become crowded with fat, or the connective tissue cells con- 
strict the kidney tubules, cells in the renal capsules die, and 
permit digested protein to escape and allow poisons to be 
retained. Another affliction of the kidneys is called diabetes. 
In this disease the glucose in the blood escapes and passes 
off with the waste. 
Fig. 203. Kidneys and Connec- 
tions. (From Hough & Sedg- 
wick: The Human Mechanism; 
Ginn and Company.) 404 
INCOME AND OUTGO OF LIVING 
Most of the excess of mineral ingredients we get in our 
food passes off with the excretion of the kidneys. These 
minerals are salt, lime, phosphates, etc. 
The Structure and the Functions of the Skin. The 
third important organ caring for the waste products of living 
is the skin. Of the three execretory organs of the body the 
skin has the greatest number of additional functions. Besides 
excreting certain wastes, the skin gives form to the muscles 
of the body, prevents the ingress of disease bacteria to the 
Fig. 204. Renal Corpuscle. 
(From Ritchie: Human Physiology; Copyright 
1908, 1915, 1920 by World Book Company, 
Yonkers-on-Hudson, New York.) 
parts beneath, contains the organs of the sense of touch, and 
regulates the heat of the body. 
There are two distinct layers in the skin (Fig. 205), the 
epidermis and the dermis. The epidermis is composed of the 
flattened surface cells of a variable number of layers, being 
greater where pressure is constant, as for example, in the 
palms of the hands and on the soles of the feet. The lower 
cells of epidermis contain brown pigment granules which 
give the characteristic color to the different races of men. 
So far as the color is concerned the difference between races 
is due merely to the difference in quantity of the brown pig- 
ments present in the deeper epidermal cells. 
The dermis contains all the specialized organs of the skin. THE STRUCTURE OF THE SKIN 
405 
The boundary between the dermis and the epidermis is 
marked by alternating peaks and valleys. On the peaks 
are located the tactile (touch) organs, which contain the 
ends of nerves and the capillaries of blood vessels. The ar- 
rangement of the tactile organs may be observed in a very 
complicated form in the ridges on the finger tips. 
-Hair> 
''Epidermis 
-TrnxeSkjLTV 
3loocL 
-Vesseis 
-Hair Follicle 
SweaV 
---Glands 
-•Fat 
Globules 
Fig. 205. Section through Skin. 
(Weidersheim: Grundriss der verg. Anatomie.) 
The organs of the skin that perform the work of excretion 
are the sweat glands. These glands consist of a slender tube 
which lies in many coils in the deepest part of the dermis, 
and extends with a few turns straight through the dermis 
and the epidermis to the surface. Many blood capillaries 
lie about the coiled base of the sweat glands, and pour out 
considerable quantities of water. The water comes to the 
surface and passes as vapor into the air. This vapor, called 406 
INCOME AND OUTGO OF LIVING 
perspiration, is escaping into the air at all times, but is 
noticeable only when because of vigorous exercise or hot 
weather the vapor is sent off so rapidly that the air cannot 
absorb and carry it away as quickly. 
At the same time that the perspiration is passing off from 
the body there escapes with the water a considerable amount 
of heat. The distinctive importance of the sweat gland is 
as an organ that aids in cooling the body through the evapo- 
ration of water. Thus, when the body is in health the normal 
evaporation of water from its surface carries off the waste 
heat of oxidation. When the nerves of the skin check the 
quantity of blood flowing into the capillaries, water cannot 
reach the sweat glands, and heat cannot escape. The tem- 
perature then goes up, and a state of fever prevails. If the 
nerves contract the small blood vessels so much that the 
supply of blood to the skin is seriously impeded, the sur- 
face of the skin becomes cold, and a chill results, although 
the interior of the body is in a state of fever. 
The Heat-Adjusting Activity. In normal health the 
adjustment of the working of the organs is so perfect that the 
temperature of the body is maintained at a point varying 
less than half a degree above or below degrees Fahr. 
Apparently this amount of heat is necessary to the proper 
working of the organs, although heat is a waste which the 
body is constantly ridding itself of. If a man exercises more 
vigorously, or engages in hard manual labor, or if he goes on 
a trip of exploration to the Far North, his body craves more 
food, and especially food of the heat-producing kind, namely, 
fat. But under all these varying circumstances the heat of 
the blood in health remains the same. 
The Hygienic and Moral Values of the Warm Bath. 
Adjacent to the tubes or follicles in which the hairs of the 
skin lie are pairs of sebaceous or oil glands. They secrete a VENTILATION IN RELATION TO HEAT 
407 
clear oil which keeps the hair soft and probably tends to 
cheek undue evaporation from the skin. But when the oil 
collects in large amounts discomfort and uncleanness of the 
body result. Then it is that a warm bath with soap relieves 
the body and gives it the splendid feeling of power which 
has real spiritual value. The late Dr. Luther Gulick, in his 
excellent book, The Efficient Life, expresses a belief that 
a bath improves the moral character of a person. 
Ventilation in Relation to Heat. As suggested on page 
402, the problem of ventilation is one connected with the 
amount of heat surrounding the body. It is also connected 
with the amount of moisture present in the air. A number of 
persons together in a room where the windows are closed, and 
no ventilating system exists, create conditions that shortly be- 
come intolerable. The heat given off by their bodies with the 
air heavily laden with moisture will act as a hot gaseous blan- 
ket about the persons there, making them extremely uncom- 
fortable, beside lowering the vitality of their bodies. Exper- 
iments of starting an electric fan in such a room have resulted 
in making the persons feel more comfortable, because of the 
breaking up of the blanket of moisture, even without chang- 
ing the temperature. The explanation of this effect is that 
more moisture may then pass off into air which has not been 
receiving moisture from the same source. If in addition, the 
air is cooled to a point approximating 68 degrees Fahr., and 
fresh air containing about 50 per cent of its maximum mois- 
ture is admitted, then complete comfort is attained. 
We all know that on a warm day in summer when the mois- 
ture in the air is considerable, or as the fact is stated techni- 
cally, when the humidity is high, the perspiration sticks to 
the body, failing to evaporate. Thus other moisture-bear- 
ing heat cannot get out from the sweat glands. On another 
day with the air relatively dry and the temperature higher, 
we may feel comparatively comfortable. 408 
INCOME AND OUTGO OF LIVING 
The existing systems of ventilation are based on the as- 
sumption that the condition to be rid of is carbon dioxide. 
In one of the commonest systems the air is made to come into 
the room at the top, and the “bad” air to go out at the floor. 
Many experts now think that the conditions of the room 
would be better if the air should be made to enter at the bot- 
tom, and the heated air to leave at the top. CHAPTER XXXVI 
THE NERVOUS SYSTEM AND THE CONTROL 
OF LIVING 
The Supremacy of the Human Brain. There are few 
persons who do not know that the brain of an animal is the 
organ that rules its body. And of course, everyone knows 
that the brain of man is the most highly organized, and is 
the greatest ruler, of all the kinds of brains that have ever 
existed. Not only does man’s brain rule his own body, but 
it even extends its dominion over all living things. As indi- 
cated in Chapter XV, p. 168, the possession of a brain supe- 
rior to the brain of other creatures makes man the ruler of all 
life. 
In spite of the general understanding of the function of 
the brain, we often hear persons speaking as if they thought 
that although the brain controls the mind and the activi- 
ties, the heart is nevertheless the organ that has control of 
the feelings. Even to-day it may appear “hard-hearted” to 
deny to that very useful organ any part whatever in the con- 
trol of the feelings or in their production. It may sound 
strange to students of the twentieth century to hear that al- 
though the ancient Hebrews believed that the heart is the 
chief seat of the soul, and of the higher feelings, they also 
thought that the kidneys are the seat of the mind. But the 
Babylonians of a still earlier day located the mind in the liver! 
It was not until about the year 500 B. C. that the Greek anat- 
omist, Alcmseon, maintained that the brain is the seat of the 
mind, of the source of feeling and of movement, and that all 
sensation is carried to the brain by means of nerves. But from 
that time until the middle of the nineteenth century very 
409 410 
THE CONTROL OF LIVING 
little accurate information about the nervous system was 
added. 
To-day however, a great mass of knowledge is available, 
not only concerning the finer structure and the connections 
of the nervous system, but also about the intricate activi- 
ties of the nerves in their control of every bit of work the 
organs of the body perform, and the basis this control gives 
Fig. 206. Dorsal View of Brains of Vertebrates. 
(From Weidersheim: Grundriss der verg. Antomie.) 
for conditions of health and for the habits of every individual. 
For many years the chief interest in the study of the nervous 
system was in the actual tracing of the connections of nerves 
with parts of the brain and with the organs of the body. 
Later the physiologists and the psychologists (students of 
the mind) carried on their interesting experiments to learn 
how the nerves acted in transmitting impulses, and how it is 
that our very habits are formed in the normal working of the 
nervous system. It may be that our moral character has its 
basis in the accumulated activities of the nervous system. 
The human brain viewed even externally is very compli- 
cated. For that reason it will be helpful to put ourselves in 
the position to comprehend it by way of evolution. Figure THE PARTS OF THE BRAIN 
411 
206 shows the upper or dorsal surface of the brain of a fish. 
You will observe that the fish brain is made up of sections of 
unequal size, and that these sections are capable of being 
separated into right and left portions. In the latter respect 
the brain is a paired organ. 
The Parts of the Brain and their Functions. The first 
portion of the brain is called the olfactory lobes. Sensations 
Fig. 207. Human Brain, Ventral View. 
(From Van Gehucten: Les Centres Nerveux.) 
of smell center there. The relatively large size of the olfactory 
lobes indicates that smelling makes up a considerable part of 
the lives of fishes. The first conspicuous section is the cerebral 
lobes of the cerebrum (Fig. 200, I). The function of the 
cerebrum in the higher vertebrates is thinking, but the fish 
is able to do relatively little thinking. The second section is 412 
THE CONTROL OF LIVING 
called the optic lobes (Fig. 206, II), and it acts as the center 
of the seeing activities. Smelling and seeing thus constitute a 
large portion of the lives of fishes. 
The third section of the brain in the vertebrate series, 
very small in the fishes and in the frogs, is the cerebellum 
(Fig. 206, III). This division of the brain appears to have 
charge of the complicated and automatic coordinations of 
the muscles. Connecting the brain with the slender spinal 
cord in all vertebrates is a tapering medulla. 
In the lower vertebrates the olfactory lobes are relatively 
larger and more important than are the lobes in the birds 
and in the mammals. The cerebrum, however, begins small 
and insignificant in the lower vertebrates and grows more 
conspicuous and important upward through the birds and 
the mammals to man. In certain groups of the lower verte- 
brates the optic lobes are enormous in comparison with the 
volume of the remainder of the brain, and in comparison 
with the size of the body. As we go up the scale, the optic 
lobes lose none of their importance as centers of seeing, but 
they become relatively less significant and finally are covered 
up by the overgrowing cerebrum and cerebellum. The cere- 
bellum starts in the fishes from a mere ridge across the brain 
behind the optic lobes, and becomes a much folded region 
in man. 
The Brain as a Central Station. The brain has been 
compared with a central telephone station or switchboard. 
The comparison is a good one, for every message from out- 
lying organs is connected and relayed at a central station, and 
sent to some other organ. There are twelve pairs of nerves 
connected with the brain on its under surface, and extend- 
ing outward to all the sense organs and to many of the or- 
gans of the upper portion of the body. These nerves are like 
cables of wires coming into the station in that each nerve is 
composed of hundreds and in some cases thousands of ex- THE BRAIN AS A CENTRAL STATION 
413 
ceedingly fine nerve-fibers (Fig. 209) capable of carrying nerve 
impulses inward or outward according to the connections at 
either end of their course. 
The first of the cranial nerves are the olfactory nerves 
(Fig. 207,1) connecting the lobes of that name with the lining 
of the nose. The impulse which results in the sensation of 
smell in the brain is conducted inward on the first pair of 
cranial nerves. The second pair are the optic nerves (Fig. 207, 
II). This pair of nerves is made up of about one million 
nerve-fibers, one end of which connects with the retina of the 
eye; the other end lies in the optic lobes. The nerves cross 
beneath the brain. In some cases the nerve-fibers within the 
optic nerves do not cross to the lobe on the opposite side of 
the brain, but in most cases the fibers do make this crossing. 
All the fibers of the optic nerves belong to the class known as 
afferent fibers; they bear impulses to the brain (Lat. ad, to; 
fere, to bear). 
There are three pairs of very small nerves numbered third, 
fourth, and sixth (Fig. 207, III, IV, VI). They are connected 
with six slender muscles which through the impulses they re- 
ceive over the nerves turn the eyes from point to point and 
focus them for vision. All of the nerve-fibers in these nerves 
are called motor-fibers since they carry impulses that cause 
movement. Thus, the sensory fibers of the second cranial 
nerves carry a message to the brain, and the motor-fibers of 
the third, fourth, and sixth carry the instructions into effect. 
The fifth pair of cranial nerves are very large, and are di- 
vided into three branches (Fig. 207, V). These cables of 
nerves carry many of the afferent fibers from the face, the 
linings of the nose and the mouth, and from the teeth. The 
efferent fibers in the nerves control the muscles by means of 
which we eat our food. The seventh pair (Fig. 207, VII) 
control the expression of the face, and are efferent fibers. 
The eighth pair (Fig. 207, VIII) of nerves is connected with 
the hearing and with maintaining the balance of the body. 414 
THE CONTROL OF LIVING 
The ninth, tenth, eleventh, and the twelfth pairs of cranial 
nerves spring from the medulla, and connect with the tongue 
and the pharynx, with the digestive system, with the lungs 
and with the heart. There are both afferent and efferent 
fibers in these highly complicated nerves. 
The Nerve Units and their Activities.——Owing to the 
great difficulty there is of investigating the finer structure 
of the nervous system, it 
is only within recent 
years that zoologists 
have learned about nerve- 
cells or neurons (Fig. 208). 
A neuron is composed of 
a nerve-fiber and a nu- 
cleus (Fig. 208) with a 
surrounding mass of pro- 
toplasm from which 
usually extend a great 
number of tree-like 
branches called dendrons 
(Fig. 208). Although the 
nerve-fiber is in some 
cases nearly as long as 
the human body itself it 
is practically invisible to 
the unaided eye because 
of the small diameter. 
With a compound micro- 
scope one may see running through the very middle of the 
fiber the axis cylinder or axon (Fig. 208). Surrounding the 
axon are one or two layers of protective sheaths made of 
fatty material which give the nerves their characteristic white 
appearance. About every millimeter of length there are con- 
strictions in the sheath which are called the nodes of Ranvier. 
Fig. 208. Nerve Cell. 
(From Stiles: The Nervous System; W. B. 
Saunders Company, Philadelphia.) REFLEX ACTION 
415 
Wherever a nerve-fiber emerges on a surface exposed to 
stimulation, such as the retina of the eye, the inner ear, the 
linings of the nose and the mouth, on the skin and in the 
various internal organs of the body—in all of these surfaces 
the axons divide into still finer branches and are distributed 
in minute collections of surface cells where the fibers receive 
their stimulation. All the fibers carry the impulse resulting 
from stimulation at less than 200 feet a second, and each 
sensory or afferent fiber carries an impulse which results 
in a single characteristic sensation. Thus the nerve-fibers 
running from the retina of the eye to the optic lobes, whether 
stimulated by light, pressure or disease cause the brain to 
make the sensation of seeing. 
If you get a splinter in your finger the nerve-impulse 
which gives you the pain runs along the axons of nerves that 
join the spinal cord between your shoulders. The impulse 
passes the nuclei of the neurons where they lie protected 
by the spinal column, and pass with the short branches of 
the neurons into the spinal cord. Here the axons branch 
many times, and connect with dendrons of other neurons 
giving over to them the impulse received at the skin. There 
are two paths open to the impulse. 
Reflex Action. By one path (Fig. 209) the impulse 
may pass to the dendrons of still another neuron which has 
its nucleus imbedded in the spinal cord and then outward 
by the motor nerve-fiber to the fine branches of the axon 
to the muscle-fibers of the muscles in the finger. The result 
of course is the immediate withdrawal of the injured finger. 
A nerve-impulse going over this path is an example of reflex 
action. By means of reflex action we save ourselves many 
times from serious injury, because the withdrawal of the 
injured or threatened member is done more quickly than 
would be possible by the other or “thinking” path. 
The thinking path is the same as the reflex action path 416 
THE CONTROL OF LIVING 
up to the point of transferring the impulse from the sensory 
fiber in the spinal cord. There the impulse passes to the 
dendrons of fibers that extend up and down the spinal cord. 
These in turn connect with neurons which cross the midplane 
of the cord and come to their termination in the surface or 
“cortical” area of the cerebrum of the brain on the opposite 
side. The pain is consciously or knowingly felt at that time, 
Fig. 209. Diagram Showing Motor and Sensory Connections. 
(From Van Gehucten: Les Centres Nerveux.) 
and the impulse is sent out by parallel fibers which connect 
soon with the motor-fibers that are connected with the mus- 
cle-fibers. 
Practically all the acts of young children are reflexes. 
Among them are sucking, coughing, sneezing, hiccups, vomit- 
ing, crying, clutching a finger or a stick, drawing up the legs, 
breathing, swallowing, changes in the size of the pupil of 
the eye, muscular contraction in fear, and pushing away 
undesired things. Some of the same acts are of course re- 
flexes for adults as well. In each case the stimulus brings a 
quick response in action, the impulse goes no further than THE SOURCE OF OUR HABITS 
417 
the spinal cord at the nearest point to the nerve bearing 
in and carrying out the impulse. 
As one grows older, other reflexes make their appearance, 
like balancing, throwing up the hand to protect the head, 
and walking. But walking is a thing that has to be learned, 
and of course the activity involves knowing what one wants 
to do. To this extent walking is not pure reflex action. 
The Source of our Habits. In the development of the 
individual another class of quick, non-thinking responses to 
stimuli makes its appearance. This class is personal and is 
not likely to be characteristic of human beings in general. 
This is the class of habits and accomplishments. Everything 
we learn to do starts from a stimulus, whether through our 
sense organs, or through the training of the muscular system. 
An essential factor in the learning process is the activity of 
the human will. The will places the sense organs into the 
proper relation to the environment to receive the stimuli 
of light, sound, taste, odor, pressure, heat, cold, and pain. 
The nerve-impulse passes with comparative slowness along 
one of the twelve pairs of cranial nerves, or one of the thirty- 
one pairs of spinal nerves up one or more relay neurons to 
the cortical layer of the cerebrum. 
Observations made on persons afflicted with nervous dis- 
eases or with injuries have made it possible for specialists in 
the study of the nervous system to determine with con- 
siderable accuracy the brain areas which control the portions 
of the body. The motor area for all the organs is located in 
a wide band that extends from near the ears across the top 
of the cerebrum. The auditory or hearing area is beneath 
the temples, and the visual or seeing area is in the portion 
of the cerebrum that occupies the back part of the head. 
The surface layer of the brain is gray in color and contains 
great numbers of the nuclei of the brain cells, while the 
deeper portion is a vast aggregation of nerve-fibers connect- 418 
THE CONTROL, OF LIVING 
ing with the other organs of the body. These fibers are 
white in color. 
There are a great many possibilities in the paths which a 
nerve-impulse may take while it is passing from neuron to 
neuron on its way to and through the cortical area. This is 
because the neurons have many branches, and through these 
branches come into contact with many different neurons. 
There is good reason for believing that with every passage 
of a nerve-impulse over an afferent series of neurons and 
a return impulse over an interlocking series of efferent fibers a 
definite association of the fibers is made, and the initial stage 
of a habit is formed. The oftener a nerve-impulse passes 
over a certain path the easier it is for the impulse to go that 
way, and the more firmly the habit is fixed. Whether the 
impulse does pass that way or by some other way depends 
upon the will. After numerous repetitions of the act the 
will needs only to initiate the action, and it is carried on 
more or less automatically. It may even be, as is thought 
by some biologists, that the cerebellum or the medulla may 
take over the control of the necessary transference of the 
afferent impulse to the efferent track. Thus, a good swimmer 
even after being a long time away from the water may start 
the process of swimming by an act of the will, when imme- 
diately he finds he can swim by the nerve tracts that learned 
the lesson long ago, and swim as well as ever. The cerebellum 
takes charge, and his brain is relieved of responsibility, if 
indeed, it could have recalled its former lessons and their 
difficulties. Similarly, a baseball player learning the art of 
striking the ball with his bat, or of catching it in his hands, 
after much wild flaying of the air, or many sprains and 
bruises of the hands, ultimately strikes the ball with a sug- 
gestion of the automatic skill of a Babe Ruth (Fig. 210), or 
catches it with the sureness of a faithful fielder. Habits 
such as these, and piano playing, typewriting, linotyping, 
weaving, etc., give to their possessors efficiency and the SOME BRAINS BETTER THAN OTHERS 
419 
saving of time. Whether the cerebellum takes entire charge 
of these activities, or whether the cerebrum maintains con- 
nection with the activity, the fact remains that thinking is 
seldom involved except to 
start the process of carry- 
ing out manual habits 
once learned. Thinking 
on some other matter may 
even be carried on at such 
times. 
Why Some Brains are 
Better than Others. 
Many problems have 
arisen in connection with 
the mechanism of the 
human brain; and many 
theories have been ad- 
vanced to account for 
some brains working bet- 
ter than others. Certain 
of the theories have long 
ago been abandoned as 
valueless. For example, 
it used to be thought that 
a person with a large head 
is necessarily possessed of 
a large brain; and a per- 
son with a large brain 
was supposed to have great mental power. Of course, 
it is true that human beings have larger brains in pro- 
portion to the weight of the whole body than has any 
other creature that has ever existed. But some of the 
largest human brains that have been examined belonged 
in life to very ordinary persons or even to imbeciles, and 
Fig. 210. Babe Ruth at the Bat. 
(© Keystone View Co., New York.) 420 
THE CONTROL OF LIVING 
some of the smallest brains weighed belonged in life to our 
ablest men. Again it was thought that the “bumps” on 
the surface of the skull could be taken as indications of the 
presence of some unusual mental trait immediately beneath. 
The absence of a bump on the elaborately charted brain area 
was thought to be proof of the absence of the trait that be- 
longed to that spot. These fanciful ideas held the attention 
of men for many years. Even to-day the “science” of phre- 
nology is believed in by some otherwise intelligent persons. 
A later theory to account for variations in intelligence as- 
sumes that the more intelligent have more and deeper folds 
in the gray or cortical layer of the cerebrum. This theory is 
still regarded by some scientists as having value. Theories 
are explanations or interpretations thought out by scientists 
to account for a known or partially known series of facts. 
While a new theory is being worked out, the old one cannot 
be given up entirely. The present or newest theory to 
account for the relative value of brains is in line with certain 
descriptions that have already been given. 
The brain is made up of neurons or cells. Connections 
are made between cells by means of the numerous fine ter- 
minal branches. It seems extremely likely that in some 
brains the connections of brain cells inherited from ancestors 
are more numerous and more perfectly made than similarly 
placed cells are in other brains. Not only does it appear that 
some persons receive a stimulus and understand an idea more 
quickly than do others, but also the ability to express a 
thought or a feeling seems naturally greater with some per- 
sons than with others. This inherited excellence is part of 
what constitutes brain organization. The other part of brain 
organization is what a person does for himself. Certain au- 
thorities regard this part as of greater importance than the 
inherited portion. 
It was once the custom to encourage boys, especially, by 
telling them that no success in life was too great for them THE WILL THE MASTER 
421 
to win, if they only made up their minds to attain it. Many 
older persons do this still, believing, however, in the pre- 
eminence of “genius.” Wiser persons nowadays are not in- 
clined to set before the young such ideals improbable of 
accomplishment as “being President,” or as becoming the 
richest man in the county,” and for more technical reasons 
than that both of these ideals are founded upon narrow sel- 
fishness. So eminent a psychologist as the late Professor 
William James (Fig. 213) of 
Harvard University many 
years ago pointed out the 
very great influence of the 
continued use of the nerve 
tracts in the formation of 
habits and ultimately in the 
formation of special and 
general intelligence and of 
character. 
Going into Training with our 
Brains. This field of hu- 
man endeavor—practicing on 
your nerve connections to 
make them do what you 
want—offers unlimited op- 
portunity for the develop- 
ment of that type of men- 
tality which we may call acquired genius, and for that brand 
of human character which may be summed up in the phrase 
complete control of one’s bodily resources. This is the game in 
life worthy of the attention of all. 
The Will the Master. One of the leading American 
writers and specialists on the nervous system was Dr. Wil- 
liam Hanna Thomson, of New York City. Dr. Thomson 
Fig. 211. Dr. William Hanna 
Thomson. (Courtesy of John S. 
Brownne, Librarian, New York 
Academy of Medicine.) 422 
THE CONTROL OF LIVING 
pointed out that the human brain with all its elaborate 
complexity does not make the thinking or the successful 
man, except as account is taken of that quality which 
drives or controls the brain, the human will. The will 
makes its first effort very early to control the brain and 
to build up the mind, which is all the material the brain 
collects in the way of experience. Dr. Thomson believed 
that the will not only stores the young mind with information 
collected from all available creation, but also that all knowl- 
edge-getting is closely correlated with the hands which 
mediate between the material world and the brain tracts of 
experience. The hands, and usually the right hand, do the 
things that result in significant ideas about such factors as 
distance, form, texture, sensation and all the qualities that 
go to make up whole ideas. 
Dr. Thomson believed that the right hand for all right- 
handed persons is so fundamentally important that its 
habitual use accounts for the location of the speech centers 
on the opposite hemisphere of the brain. Right-handed per- 
sons vrho have been paralyzed on the right side only are 
still able to see with their eyes, taste with their tongues, to 
hear well, and to breathe satisfactorily, because these organs 
are connected w ith functioning nerves from the unparalyzed 
left side. Left-sided paralysis of right-handed persons does 
not interfere with the speech or other idea-receiving or idea- 
expressing centers. The obvious way to account for these 
facts is to suppose that the hand is of great importance in 
developing the powTer of expression. Observations have been 
made in cases where parents or teachers have tried to change 
the natural inclinations of children from left-handedness to 
right-handedness. A definite result has seemed to be that 
the children were put back in the learning process. 
The closest scrutiny of human brain tissue by means of 
microscopic study has failed to reveal any structure on one 
side of the brain that is not present on the other, and yet it WORKING UNDER THE WILL 
423 
seems to be evident that one side of the brain has powers 
that the other does not have. This appears to indicate that 
the brain can be trained through the connections it already 
has, and that the human will may operate effectively with 
what the brain already possesses. 
Nerve Activity without the Will. However, one portion 
of the nervous system is outside the domination of the will. 
It is called the Autonomic Nervous System (Fig. 212). In 
the old text-books it was called the sympathetic nervous 
system. This portion of the nervous system is “self-regulat- 
ing,” which is the meaning of the word autonomic. The chief 
centers of this system are located in two chains of ganglia 
lying in the body cavity adjacent to the backbone, and con- 
nected by nerve cords into two lines extending forward 
and backward. There are other autonomic pathways, 
such, for example, as the tenth cranial or vagus nerve. The 
autonomic system is made up of a complicated series of 
“paired” or “opposite” nerves by means of which adjust- 
ments in the work of the organs of the body are made auto- 
matically. The stimuli which start into operation a given 
set of autonomic nerves are present in such conditions as 
food either actually in the stomach or only visible to the eye. 
The autonomic system secretes digestive fluids, the saliva 
in the mouth or the gastric juice in the stomach. The need 
of oxygen in the muscles or the presence of carbon-dioxide 
waste are conditions which will stimulate the heart, the blood 
vessels, and the lungs to varying degrees of activity. The 
degree of activity in health is adjusted by the working 
together of the paired nerves. 
Working under the Will. Although the operations of 
the internal organs cannot be modified by a direct act of 
the will, there are ways in which indirectly they may be 
influenced greatly. We may eat at one time or at another, 424 
THE CONTROL OF LIVING 
or we may run or not run as we please, or we may breathe 
fresh air or impure air as we like, or we may keep our bodies 
Neck Plexus') 
Pharynx Plexus 
Atm Plexus. 
Bronchial Plexus 
-Heart Plexus 
~K sophagtis 
PI OXU.S 
—Stomach. 
Plexus 
_ Celiac Plexus 
Lunvbap 
Plexus 
Sacra,! - 
Plexus 
Fig. 212. Autonomic Nervous System. 
(From Herrick: Neurology, W. B. Saunders Company, Philadelphia.) 
in health or not as we choose. It is not generally known, 
however, that we may bring the will to bear upon conditions WORKING UNDER THE WILL 
425 
that will determine the extent to which certain very small 
but very important glands secrete their fluid. These are the 
ductless adrenal glands, lying adjacent to the kidneys. Some 
basic facts connected with this matter were given on page 383. 
We know that during periods of great emotional stress, 
such as fear or anger, an increased amount of adrenalin, 
the secretion from these 
glands, is poured into the 
blood. The effect of this 
chemical is to cause sus- 
pension of the work of 
the digestive glands, while 
stimulating to greater ac- 
tivity the nerves that con- 
trol the skeletal muscles. 
The point was made that 
strong emotion at the time 
of meals works ill to the 
digestion, and that anger 
at that time must be care- 
fully avoided. But adren- 
alin has important uses, 
and is coming to be looked 
upon as a valuable chem- 
ical resource. About 1896 
Professor William James 
called attention to the fact that every person had withir 
his body a very great supply of untapped capacity foi 
work. Nearly everybody knows that once in a whih 
unusual need arises for the sustained and severe expendi 
ture of muscular and nervous energy. Sometimes we art 
surprised at our own feats or at the feats of others. Pro 
fessor James maintained that the unusual might become tht 
common occasions with great profit to the productiveness oi 
the human race. Not that we should wrack bodilv machines 
Fig. 213. Professor William James. 426 
THE CONTROL OF LIVING 
in “speeding them up” to the limit of their endurance, hut 
that we should deliberately calculate to make our bodies 
“pay for their keeping” by giving them all they can do 
efficiently while we work—and then letting them enjoy a 
good rest. 
In recent years skilled experimental physiologists have 
learned that the coming of fatigue through the formation of 
certain fatigue poisons in the muscles may be postponed by 
the presence of adrenalin. The adrenalin is poured out 
under the control of the autonomic nervous system during 
great stress of emotion; but emotion is subject to consider- 
able control by the brain and central nervous system. This 
is the indirect control we may exercise over the work of the 
adrenal glands. The practical problem then is to discover 
some means by which persons may easily and naturally 
approach efficiency, and make as complete use of their 
resources a great deal of the time as was done once by a tired 
farmer boy, who at the close of day welcomed a suggestion 
to go swimming, and while in the excitement of the sport 
responded swiftly and successfully to the call for help from a 
boy smaller than he. 
Work and its Enjoyment. There is a difference of 
opinion among many persons as to whether work is really 
enjoyed by the persons doing the work. We have proof 
enough that enjoyment is a prerequisite to efficiency and 
to the accomplishment of a considerable amount of work. 
A ditch-digger and a poet who are stimulated to work simply 
by the necessity of having something to live on may be 
equally indifferent to the quality of their work, however 
much the public may indicate its preference for the work 
of the ditch-digger by paying more for it. Still, we should 
not decry the value of the food stimulus to any worker, for 
no less a poet than James Russell Lowell considered it forr 
tunate and a stimulus to industry in writing poetry that one HABITS AS TOOLS FOlt LIVING 
427 
must work in order to have something to eat. But when 
one can say sineerely that he has added the great stimulus 
of enjoying his work, there is present the condition of a 
natural and easy approach to productiveness. 
Persons whose physical resources are slight or whose wills 
have not been trained to drive ahead the physical resources 
swiftly and efficiently often exclaim in wonder at the physical 
or mental labor accomplished by others. And frequently 
advice is given to hard workers to spare themselves, or they 
will “have nervous prostration.” A classic instance of a 
career important in biology is that of Charles Darwin who 
in spite of serious illness throughout a long life accomplished 
a prodigious amount of work. Work did not make him 
ill, and it seldom if ever causes anybody to break down. 
There are, however, certain contingencies which may operate 
to cause the breakdown, and not the least of these is the act 
of stopping work. Another is that a person may be so un- 
wise as to cut down his sleeping time. But the two great 
contributing causes to nervous breakdowns are unhygienic 
eating and an uncontrolled will that wanders into worries. 
If a person feeds himself as carefully as he would feed 
a horse of which he expects a humane amount of service, 
he would have attended to the first requirement. If in the 
early days of his existence a person has provided himself 
with a store of reasonably good mental and physical habits, 
then he should have no worries. 
Habits as Tools for Living. We find in this chapter 
that we have come around again to the topic of habits. It is a 
good subject to talk over once more, for habits are the 
equipment of life. In a very important sense they are the 
spiritual tools of our existence. Professor James said there 
are three classes of habits: good, bad, and those that are 
neither good nor bad. The good, of course, we will cleave 
to as we would to a good bat that has served us well, or to 428 
THE CONTROL OF LIVING 
a friend who has stood by us. The bad we shall try to break 
up by interposing chains of associations that will imper- 
ceptibly take their places. The tracks of the old bad habits, 
both physical and mental, are there, but we may be able to 
cover them up by not using them, or possibly by giving that 
portion of the mind which manifested them more profitable 
work to do. 
The habits that are neither good nor bad Professor James 
said should be changed now and then anyway. This sugges- 
tion may be somewhat mystifying until we understand that 
habits that are neither good nor bad are mostly those which 
make up our personalities, especially those elements which 
neither help nor hinder other persons particularly. For 
example, if you know that a certain key will unlock your chest 
of drawers, and some day you lose the key, you are put to 
serious inconvenience unless you are able to change that 
habit of opening the chest with a key, and can solve the 
problem with a button hook or with a piece of wire. Anyone 
who learns early to solve all manner of physical problems 
seldom finds himself a prey to circumstances; he controls 
them. It goes without saying that the almost universal 
childish desire to “do it myself,” to which we referred in 
Chapter I, makes the easy approach to the acquirement of 
the valuable habit of being able to adapt oneself to unex- 
pected circumstances. It was suggested in that chapter that 
older persons make a great mistake when they take from the 
young the opportunity to learn how to get out of difficulties 
more or less unaided. 
Similarly, in the matter of getting ideas about things, 
there are many persons who have learned nearly all they 
know of life from books. Their information is usually more 
or less stereotyped and uninteresting, and they are very dry 
persons themselves. They are drier still when they pore 
over books of one sort dealing with a narrow field of informa- 
tion. On the other hand, persons who seldom read a book HABITS AS TOOLS FOR LIVING 
429 
cut themselves on Irom being in touch with other minds 
that have looked upon life from different points of view. 
Those who work with their hands all the time, or engage in 
commercial or other financial pursuits all the time, or travel 
all the time, or do nothing in particular all the time, never 
“touch bottom” in dealing with the mental or moral prob- 
lems of life, and indeed never have any of the real fun of 
getting the better of the dif- 
ficulties that arise in the 
higher realms of living. In 
short, they never learn the 
habit of adapting their minds 
to new situations and of keep- 
ing their minds free from 
worries and fresh and young 
while growing older physi- 
cally. Dr. Thomson has 
called attention to the val- 
uable trait of keeping our 
minds young. He tells the 
story of the great English 
statesman Gladstone, who 
throughout a public career 
of sixty-six years never lost 
the power of directing a flexi- 
ble and vigorous intellect toward any matter mat de- 
veloped out of his experience in a long and successful 
leadership. The mind of our own great Lincoln had that 
same freshness and freedom from rigidity to so great a degree 
that he was able to save himself from breaking down in our 
long and troublous Civil War. Many equally active but less 
well known persons live their lives with considerable satisfac- 
tion to themselves and with great benefit to society in general. 
It pays to keep our habits that are neither good nor bad from 
becoming fixed. Thereby they really become “good” habits. 
Fig. 214. William Gladstone. 430 
THE CONTROL OF LIVING 
The Independent Mind. It would never do for anyone 
to plan for himself a mind like Gladstone’s or Lincoln's even 
if his ancestors had given him the basis for such a mind. 
The prime quality of a flexible mind is its independence. 
“Copy cats” are always ridiculed. It would be a fortunate 
circumstance if our system of education permitted more 
opportunity for everyone concerned to have wide ranges of 
experience. Not only would 
that give each one a chance 
to know what many groups of 
mankind do, and how they do 
their work, and so whether 
we individually would care to 
carve out a career in the 
same fields. But it would 
also furnish us with some 
understanding of the social 
relations existing between 
different bodies of mankind. 
In these two lines, therefore, 
we would be set to thinking, 
for thinking is what the mind 
does when it comes up 
against facts. Out of our 
thinking come the ideas which deal with facts and make 
them understandable to ourselves and to others. “That’s 
a good idea,” we say. This means that some one has set 
his brain to work on a problem and has solved it, or has made 
a fair start toward solving it. 
Our civilization has paid perhaps too much homage to 
persons who have had ideas and could put them into attrac- 
tive form. Many persons are so lacking in self-respect that 
they always seem anxious to have the idea or the opinion of 
another person,—of almost any other person. Perhaps this 
has had something to do with the fact that unscrupulous 
Fig. 215. Abraham Lincoln. THE IDEALS OF A THINKING BRAIN 
431 
persons have been able to have considerable success in ab- 
stracting money from the funds of those who showed so much 
dependence. Although we may blame our system of education 
for the prevalence of the dependent habit mentioned, we 
must not forget that in past ages it was only the few who were 
supposed to be able to think and to have authority as think- 
ers. W e now realize, however, that genius is largely a matter 
of mental discipline and of dealing with many experiences 
by thinking through them to the underlying ideas. Therefore, 
we need mostly to encourage a wider use of the habit of having 
a great variety of experience, of letting our individual minds 
do their own thinking, and developing their own ideas. 
The Ideals of a Thinking Brain. There is still another 
important step which the thinking brain will take almost of 
itself. It will form ideals. One of the most valuable of con- 
tributions which a thinking brain may make in the interest of 
its fellow beings is a clean ideal, a good ideal, a high ideal. The 
thinking brain may also create a selfish or a destructive ideal. 
What the brain does, depends on what the will makes it do. 
An ideal is the image of what one is working toward; it is the 
imaginary form of what an object in life will look like when 
it is accomplished. It is easy enough to describe an ideal, 
because everyone has them. For example, I want to make 
a lot of money, because men are estimated on the basis of 
their wealth; or so that I may subscribe freely to public 
charities, and to the aid of deserving persons. Or I want to 
be paid well for my work, because I regard my work as im- 
portant, and as being well done. Or I want to have a good 
balance in the bank, so that my family may live in comfort. 
Here are a number of ideals about money which may or may 
not constitute the chief ideal of a person’s life, and are to 
some extent selfish, to some extent good, and to some extent 
mixed or incomplete. 
The ideals of most persons are selfish, even when they 432 
THE CONTROL OF LIVING 
flatter themselves that they are doing it all for their fami- 
lies. A considerable number of persons have mixed or in- 
complete ideals. This is mainly because it is not the easiest 
of problems to develop ideals that hold well together logi- 
cally, that are sincere, and that have the virtue of being prac- 
tical in the long run, not on the basis of cash in hand, but on 
the basis of some great good to be attained in the lives of all. 
Persons of thoughtful temperament and of analytic in- 
clination like to work out their own ideals, and to plan and 
shape their careers. For, anyone can see that a career that 
is shaped has the chance of getting somewhere, while those 
careers that are not planned may drift anywhere,—and usu- 
ally do. So powerful is the human will over circumstances 
that a well-conceived plan and a set of ideals will, figuratively 
speaking, especially if joined with other wills, force itself 
through steel and concrete battlements. In spite of great 
obstacles which everyone knows exist, marvelous accom- 
plishments have been won by millions of ordinary human 
beings. Everyone of us ought to try to be one of those mil- 
lions, and thus justify our existence to our own conscience, and 
also fill out a career happy and generally satisfactory to our- 
selves and useful to mankind. 
The cultivation of ideals is one of the most interesting oc- 
cupations the mind can engage in. Persons who find pleasure 
and satisfaction in the pursuit of finer and cleaner notions 
of living, and in associating with other persons with ideals 
of similar kind, have gone a long way toward actually liv- 
ing finer and cleaner lives, for the thinking and the associat- 
ing make the possibility of doing. Such persons are not 
likely to need the advice of the nerve specialist either. Ideals 
are not merely dreams, but they are clearly conceived 
thoughts that take hold of the mind and the body, and make 
them over, if that is necessary. They carry the person into 
good company or bad company according to the nature of 
the ideals. They make or mar his very existence. It was THE IDEALS OF A THINKING BRAIN 
433 
ideals of a dangerous kind that brought on the World War, 
and it is ideals that may make universal and continuous 
peace possible when mankind comes to have consistently 
conceived ideals of that kind. The universal will determines 
what mankind shall be and do. CHAPTER XXXVII 
TIIE SENSE ORGANS AND THEIR CARE 
The organs of sense constitute the transforming stations 
between the contacts of experience and the central nervous 
system. Grains of sand may be blown against our faces. The 
contact of the sand with the skin is immediately transformed 
in the touch organs or nerve endings in the skin into a message 
to the central nervous system. A mouthful of hot potato or 
a piece of ice on the skin stimulate the temperature sense 
organs, and they transform the condition of heat or cold into 
a message to the central nervous system. 
The organs of taste in the mouth and the organs of smell 
in the mucous membrane of the nose transform the chemical 
stimuli into nerve messages which result finally in sensations 
of taste and smell. The complicated ear transforms the air- 
waves of sound into the phenomenon of hearing. The eye 
transforms light wave stimuli into nerve messages which 
result in the sensation of sight. 
Regarded in another way the organs of sense serve as 
the gateways to our knowing powers, our understanding. 
Through these several gateways the world, its facts, its ac- 
tivities and all that is done in it may flow into and increase 
our knowing, our consciousness. Without the sense-organs 
there would be no way for us to know anything. Without 
knowing, individual conscious existence would be impossible. 
The perfect working of the sense-organs is brought about 
through the normal development of the individual, and by the 
protective care of those sense-organs that are most liable to 
be injured. The most susceptible to injury are the eyes and 
the ears. The organs of touch, although not liable to injury, 
434 THE SENSE ORGANS AND THEIR CARE 
435 
are capable of being trained to delicate activities, as for ex- 
ample, they are among jewelry workers and others who 
handle delicate or small objects or carry on intricate activities 
with their fingers. The organs of taste are capable of being 
trained and made more discriminating, as among tea-tasters. 
Skilled musicians gain their capacity to play difficult music 
through long training of the ears, coordinated with the 
delicate control of finger and arm muscles. The eyes also may 
be trained to see things that are unnoticed by the average 
person. 
Ordinarily, we may not think of the tactile (touch) and 
temperature sense-organs as being protected, but they are. 
These sense-organs lie beneath the skin, or in membranes 
within the body. The organs of taste and smell are pro- 
tected within special cavities. The ear appears to be an ex- 
ternal organ, but the external part is only the sound wave- 
collecting portion of the ear. The middle ear is within the 
skull, and the membranous “drum” separates it from the 
external ear. Deep within the skull beyond the middle ear 
lies the inner ear with its complicated structure and its 
auditory or hearing nerve endings. No sense-organ is so well 
protected as the ear. 
The eyes are set in deep, fat-lined sockets in the skull. 
The eyeball is inclosed in a very tough coat, and over the 
eyeball lie eyelids, eyelashes and eyebrows which keep out 
dust, strong light and perspiration. The swift contraction of 
muscles in the eyelids protects the eyes ofttimes from serious 
injury without our thinking what is happening. At the outer 
corner of each eye is a lacrymal or tear gland which pours out 
a watery solution that flows over the eyeball into the tear- 
ducts leading to the nasal chamber. 
Nature’s provision for the protection of the sense-organs 
must be supplemented by intelligent care on the part of those 
who are old enough to understand the reasons for extra care. 
Those who have “colds in the head” realize that the mucous 436 
THE SENSE ORGANS AND THEIR CARE 
membrane of the nasal chamber is inflamed and covered with a 
large amount of mucous. Capacity to detect odors is reduced 
to a great extent, so much so that we sometimes realize that 
certain things we thought we had always tasted were really 
smelled. 
THE CARE OF THE EARS 
Sometimes in the winter time the doctors have a great 
many cases of “ear trouble.” These for the most part are 
the cases of children. They have “running ears.” Our 
grandmothers, or at least our great-grandmothers, did not 
think much about them. As a matter of fact running ears 
may become sources of grave danger, because a case of 
running ear may be associated with mastoiditis. 
Running ears come from inflammation induced by bacteria 
passing up the Eustachian tube from the pharynx to the 
middle ear. Pus gathers in the middle ear, and finally bursts 
the drum or tympanum of the ear. Pain in the ear is some- 
times the sign that the drum is stretched by the presence of 
pus. It is much better to have the drum lanced, because 
before the drum bursts naturally some of the bacteria may 
get into the spongy bone spaces and induce mastoiditis. 
Lancing insures perfect draining. This is properly accom- 
panied by syringing with normal salt solution or boric acid to 
assist in keeping the external ear passage free from injurious 
bacteria. Sometimes erysipelas bacteria get into the running 
ears if the draining is imperfect. Once in a while an after 
effect of measles is running ears and mastoiditis. A good 
doctor keeps a close w'atch on the eardrum in all measles 
cases. Nowadays, intelligent families keep on hand an ear 
syringe which permits of wrater going in one tube and the 
waste coming out another. In a vreek or two a lanced ear- 
drum will heal up, and the hearing of the patient usually is 
not affected. 
Many persons have a very bad habit of “picking the ears” THE SENSE ORGANS AND THEIR CARE 
437 
with the head of a pin or with a toothpick. The effect of this 
habit is to irritate the eardrum, and also to irritate the skin 
of the external ear passage, thus causing the formation of a 
small but painful ear boil. The best way to free the ears of 
excess wax and of dirt is to cover the blunt end of a toothpick 
with absorbent cotton, dip it into warm water, and with this 
clear the external ear passage carefully. 
Earache with children is sometimes the result of the harden- 
ing of a thick layer of wax on the eardrum. Doctors sometimes 
prescribe “drops” for softening the wax. Warm water and 
a syringe will also remove the cause of the trouble. 
THE CARE OF THE EYES 
The things that young people do to their eyes tend to bring 
on trouble which later in life they try to correct by using 
eyeglasses. Among these bad habits in mistreating the eyes 
are reading in a dark corner of the room, reading with the 
face to the source of light and the printed page in the shadow, 
reading in bed, reading in unnatural and awkward positions 
that induce strain on the part of the eyes in accommodating 
themselves to the unnatural positions. 
Eyestrain tends to become chronic, and may go from bad 
to worse, ending in relative helplessness to use the eyes 
efficiently. Various bodily disorders tend to aggravate eye- 
strain. Good health and exercise, including exercise of the 
eyes themselves, tend to bring the eyes back to normal 
condition. The great biologist, Charles Darwin, suffered 
much from eyestrain which was associated with intestinal 
difficulties. 
When the eyes of a human being are suffering from eye- 
strain, or from strabismus (cross-eye), from near-sightedness, 
or from far-sightedness, the oculist usually prescribes eye- 
glasses with particular specifications of degrees of curvature 
of the lenses. If the eyes become unsuited to the glasses, the 
lenses must be changed for others with different curvature. 438 
THE SENSE ORGANS AND THEIR CARE 
Usually that is the most that is done. However, experiments 
among oculists and others show that systematic daily exer- 
cise of the eyes on “Snellen cards” do help the eyes to be 
relieved of strain and other affections. Possibly this line of 
experimentation holds much satisfaction for the future. It 
seems so, although glasses may still be useful in certain cases. 
It does seem somewhat lacking in reasonableness that of all 
the sense-organs the eyes should be subject to an uncom- 
monly large group of hindrances. It also seems inappro- 
priate that about the only treatment given is a mechanical 
one, the nature of which indicates that something is missing 
from the eyes. There are two ways out for young people, one 
is better care in youth, the other is more exercises with the 
eyes themselves. 
When particles get into the eye, the lids maybe turned back 
and the particle cleared off with a soft cloth or brush used by 
another person. As a rule, the glass eye-cup containing boric 
acid is the best thing to use to clear out the particle, as it aids 
the natural movement of the tear fluid which flows across 
the eye from the lacrymal gland at the outer corner of the 
eye to the tear duct at the inner corner. In cases of in- 
flammation of the membranes of the eyes, the eye-cup and 
boric acid are also helpful. Besides, children like to use the 
eye-cup. It is fun, and the treatment gives the eyes a feeling 
of comfort. Incipient eye infections also may be warded off 
in this way. However, the most dangerous eye infections are 
liable to menace the sight of the child at birth. It is the 
custom now for doctors to drop some silver nitrate into the 
eyes of the new-born child as a precaution against infection, 
which otherwise might cause permanent blindness. 
The proper care of the sense-organs not only insures the 
retention of valuable aids in making our way through life, but 
it also makes possible our very existence as normal human 
beings. CHAPTER XXXVIII 
THE BONES AND THE MUSCLES; 
AND THEIR PROPER CARE 
The Skeleton. A man is very little taller than his 
skeleton (Fig. 93), and very little broader than the bones of 
his shoulders and his hips. The bones of his head, chest, arms, 
and legs are but slightly different in shape from their entire 
parts in life. Thus, it can be said truly that the skeleton 
gives form to the body. 
Mechanically the skeleton is more wonderful than any 
form-giving structure that has ever been invented. This 
is true of the skeleton as a whole, as well as of any of its 
parts. The entire skeleton gives form to the young child, 
newly born. But this form is quite different from the form 
of the grown man, and the difference is brought about 
by a gradual process of change taking place in the parts 
naturally and readily while the body continues at work. 
Young bones are soft, being composed in large part of car- 
tilage. Even when the bones have become harder, they are 
growing longer and thicker by a process in which the hard 
tissue is destroyed, and its place taken by new hard mate- 
rial. There are certain cells called osteoclasts, the busi- 
ness of which is to destroy bone cells, making way for more 
bone cells of the same kind. There are many other instances 
in the skeleton of mechanical adaptations to the needs of 
the body. 
That important organ which rules the body, the brain, 
is protected in a rounded box by bony plates being fitted in 
a complicated system of mortised and tenoned joints. Any 
ordinary jar or shock cannot injure the brain. No pillar 
439 440 
CARE OF BONES AND MUSCLES 
ever made has the flexibility with the strength that is pos- 
sessed by the spinal column. This flexibility is obtained by 
the drawn-out S-shaped curve of the whole column and by 
the elastic cartilaginous pads alternating with the bony 
sections of the column. The vital organs in the chest cavity 
are protected by the arched ribs which resist pressure. The 
ribs at the same time are adjustable to permit the up and 
down movement characteristic of breathing. 
All the long bones are curved, adapting them to ready 
bending. They are also hollow, giving greater strength for 
the same amount of material, and greater surface for the at- 
tachment of the tendons of muscles. At all movable joints 
the bones are wider, thus distributing the wear over more 
square inches of surface. The greatest flexibility and variety 
of movement is attained at the wrists and in the fingers, 
where the bones are small and numerous, and the surface 
for movement relatively very large. 
The Care of the Skeleton. The most we can reasonably 
advise in regard to the care of the skeleton is to suggest 
that everyone help to create such conditions of work, and 
also of play, that the risks to “life and limb” will be reduced 
to the minimum. Without doubt these risks are far greater 
now than is necessary. 
The first care that is needful to give the bones is in the 
way of proper food. The principal food of bones is lime and 
phosphorus and their salts. There is the dreadful disease 
called “rickets” characteristic of childhood which comes 
from neglect, or inability, of parents to provide those foods 
which contain vitamins, referred to on page 349. Per- 
sons of all ages must have the mineral salts, but the need 
is particularly one of growing individuals. The young es- 
pecially need the vitamins. 
The white race, like others, has strange ways of deform- 
ing the skeleton for the sake of “beauty.” We do not flatten THE CARE OF THE SKELETON 
441 
the head with a board, nor bind the feet so that they wil 
not grow larger than a child’s. Once, we girdled the trunl 
until the ribs turned in like the neck of an hour-glass. Hap- 
pily, public scorn and growing intelligence has turned stronglj 
against this habit. But we are now under the spell of the faci 
of tipping the foot forward with high unstable heels, so that 
the weight of the body rests on the toes. We smile at the 
pictures representing the appearance of the skull of the Flat- 
head Indians, and pity the Chinese women of an early day. 
But their age-long customs are now being altered rapidly, 
while our bone twisting habits are the results of shallow 
fashion under civiliza- 
tion, possibly to be re- 
placed by some other 
whim equally bad. Al- 
though the waist-binding 
habit of women in the 
civilized world is being 
modified, the vice of 
wearing high heels has become so firmly fixed in the early 
part of the Twentieth Century that it is impossible to buy 
ready-made certain qualities of women’s dress shoes with 
sensible low heels. 
Many persons think the reform of dress for women is a 
problem for the women themselves to work out. To a cer- 
tain extent this may be true, but it appears that a stronger 
campaign could be made on the basis of improving the con- 
ditions of comfort and health for all persons as human be- 
ings. Of late years a form of shoe known as the “army shoe” 
has come into general use in the army of this country, hun- 
dreds of thousands of pairs having been sold by certain firms 
that make a specialty of this particular type of shoe. Men 
outside the army in all branches of life have experimented 
with these shoes, and have increased their comfort greatly 
thereby. The shoes are broad, with thick soles, and with 
Fig. 216. Fashionable Heels and Army 
Shoes. 442 
CARE OF BONES AND MUSCLES 
low heels that run well under the foot. Women who are 
interested in the development of better conditions for them- 
selves and for other women will doubtless ask that the same 
ideas be carried out by manufacturers for them. 
There is an organized effort in this country being furthered 
under the name of the Correct Posture League which is 
endeavoring to create better ideals leading toward the more 
Incorrect Posture 
■ Weak or fatigue porturei 
The neck and trunk form 
a zig-zag line 
Correct Posture 
' Strong, healthful, be.ut.ful .nd efficient > 
The neck and trunk form a 
straight, vertical line 
Exaggerated Posture 
iRifid, ugly and harmful’ j 
This posture can be held only for * 
a short time and with great effort 
Fig. 217. Standing Postures. 
(Courtesy of American Posture League.) 
satisfactory development of the body. Although some of 
the directions given for maintaining the proper posture are 
especially applicable to the muscles, most of them apply to 
the skeleton as the fundamental structure involved. Our 
sitting and standing positions in time give the skeleton its THE MUSCLES 
443 
permanent set. If we practice on keeping our shoulders 
back, and well squared, our chest high and arched forward, 
and the neck perpendicular, we shall effectively counteract 
another foolish fashion known as the “fashionable slouch.” 
Modern desks at school are made so that the back fol- 
lows the natural curve of the human form, and gives it sup- 
port where it is needed. They do not shove the trunk for- 
ward at the shoulders, thus leading to the strain that makes 
one want to try all attitudes to obtain relief. 
The Muscles. Every movement made by the body 
or by any of its parts involves the activity of a muscle. The 
muscle acting may be as great as those of the back and the 
leg, or it may be composed of relatively few cells. In any 
case the activity always results from the contraction of the 
muscle cells. The contraction of the muscle is brought about 
by the stimulus that travels along the efferent nerve fiber. 
The way this happens is explained in Chapter XXXVI. Al- 
though muscular tissue is accustomed to respond to the 
stimulus carried by nerves, experiments have shown that 
muscles have the power of contracting when a stimulus is 
applied to them directly. 
The best known muscles of the body are under the control 
of the will, being connected with nerves that join directly 
with the spinal cord and brain—the central nervous system. 
These are sometimes called voluntary muscles. Other muscles, 
as for example, those of the stomach, intestines and other 
visceral organs are under the control of the autonomic nervous 
system. This connects indirectly with the central nervous 
system, but is not under the supervision of the will (seep. 421). 
The muscle cells of the first kind are spindle-shaped and 
marked by numerous cross markings, for which the name 
striated is used. The involuntary muscles are made up of 
plain, flattened muscle cells. 
Nearly all of the voluntary muscles are connected to 444 
CARE OF RONES AND MUSCLES 
bones by means of tough ligaments or tendons (Fig. 218). 
Movement of a part is brought about by the contracting 
muscle pulling on the tendon, which in turn brings the bone 
nearer to the central part of the skeleton. A few muscles, 
like the circular muscle around the mouth, contracts and 
performs its function without involving any movement on 
the part of a bone. 
Work and Rest.——Every muscle of the body should be 
put to work; and each should also be allowed its chance to 
rest. The full development of all the muscles requires their 
Brachialis 
/Weight 
Fig. 218. Muscle and Ligaments. 
(From Mackenzie: The Action of Muscles; Paul B. Hoeber, New York.) 
Power. 
'"Fulcruaa 
being employed regularly in their several functions. Other- 
wise, degeneration ensues. Yet, even in the healthy con- 
dition of muscles they tire of their labor, and must rest. 
The heart itself rests, for between the beats the muscle fibers 
recuperate. The stomach and the intestine have more rest. 
The voluntary muscles also require their opportunity for 
recuperation, which they obtain chiefly during sleep. But 
they need more, and under proper living conditions get it 
while the person is lying down, or sitting at ease. 
In Chapter XXXVI some suggestions were offered on the 
point of having useful occupation for the mind. Much of 
what is given there applies to the value of occupation for 
the muscles. But aside from the mental uplift one gets from 
using his muscles in productive labor, the muscles themselves ATHLETICS 
445 
have the needed stimulus to development; and they are 
educated by the training for performing their labor with 
increasing efficiency. 
Every person who can engage skilfully in various kinds 
of manual effort grows in power to control his environment, 
and incidentally commands greater respect among his fellows 
than he would without this ability. The all-round man may 
not be a great man in the estimation of the world, but he is 
more likely to be a perfect man in the sense that fundamental 
weaknesses are not so liable to exist. Besides, he is sure to 
be the happiest man of any, for he has so many anchors 
on life itself. 
Athletics. Fisher and Fisk in their book, How to Live, 
say there are two great forms of activity, work and play; 
and that there are two great forms of inactivity, rest 
and sleep. Rest and sleep are of course absolutely necessary. 
And so are work and play. But work and play seem more 
full of inspiration, for it is more obvious that something is 
being done. 
Work is the great function of adult life; and it is a man’s 
job. Play is the thrilling interest of childhood; and it is also 
the training school of the mind and the muscles for the 
more solid business of mature years. Athletics is the or- 
ganized play of the adolescent period. As such it has im- 
portant biological and also educational value. 
Athletics in schools was practically an Anglo-Saxon in- 
stitution in the beginning, starting in England and spreading 
to America. In America athletics has become general. 
The boys of every race represented in the schools and col- 
leges take part with eagerness, showing that custom and 
systems of education in other countries have been responsible 
for the absence of athletics in their schools. 
City schools engage in athletics more than do country 
schools. This is partly due to the greater development of 446 
CARE OF RONES AND MUSCLES 
city schools, and partly to the fact that city boys crave the 
activity that comes to country boys more readily. Yet 
country boys have play energy to spare, and where organized 
play has been developed prove their ability fully. Organized 
play will perform the same useful function for boys from any 
environment, and for girls whose mothers never had the op- 
portunity of engaging in the modern games. Athletics, of 
course, develops stronger 
muscles, but it also aids 
in the attainment of phys- 
ical poise, symmetry of 
form, and the harmonious 
adjustment of the vari- 
ous parts of the body. 
And incidentally, through 
athletics the organic func- 
tions of the body, diges- 
tion, circulation, assimila- 
tion, elimination, are car- 
ried on more perfectly. 
A very useful phase in 
the development of ath- 
letics in the schools is the 
fact that games are being 
introduced in the daily 
course of study. This in- 
sures proper attention being given to the organization of 
play, and to the need of every young person being put down 
for some of the training that in the early days of athletics in 
America used to go to the favored boys with the largest 
shoulders and the swiftest legs, boys who needed the training 
less than others. 
Athletics is for young human beings, and not for boys 
alone. Thus, all forms of athletics that will bring the results 
sought should be employed, for both boys and girls with 
Fig. 219. High School Boys in Cross 
Country Run. 
(© Keystone View Co., New York.) OVERWEIGHT AND UNDERWEIGHT 
447 
whatever modification in form experience suggests. To 
football and baseball we have added basket ball, captain ball, 
prisoner’s base, dancing. 
As our various forms of athletics develop still further, we 
may bring in more of the spirit which the Greeks displayed 
in their games, the spirit of imagination and beauty. It 
appears that one school of wrestling in Russia holds to the 
importance of beauty in the play of the muscles, anti in their 
development. 
A practical value of athletics from the point of view of 
educational administration is recognized by wise educators 
as a means to the normal development of “school spirit” 
or “college spirit.” Pride in the school team in football, 
baseball, or basket ball may easily grow into pride in the 
institution as a whole, in the scholarship of the school, and 
in its standing in the community. 
Overweight and Underweight. A person may gain in 
weight by the addition of muscular tissue, and of course 
muscular tissue is added until adult years. But considerable 
increases in weight in youth, and moderate increases in 
weight in adults is liable to be due to the storing up of fat 
cells between the muscles and about the thin membranes near 
the intestine. As a person grows stout the amount of sur- 
face in relation to the weight of the body decreases, thus low- 
ering the radiating surface for heat. Hence, foods that 
might develop heat energy are diverted into energy stored 
in the form of fat. Those who are fat tend to grow fatter. 
In some cases overweight may be corrected by means of 
athletic exercises, but usually it cannot be corrected in that 
way. Perhaps as many quack doctors prosper at the expense 
of overweight persons as from any other physical ill. None 
but the most reputable physicians should be trusted in any 
case. 
There are certain kinds of food which are best for over- 448 
CARE OF BONES AND MUSCLES 
weight persons to eat. Among these are lean meat in small 
quantity, vegetables that do not have high percentages of 
starch, such green vegetables as carrots, parsnips, beets, etc., 
and fruits. One should avoid much sugar, fats, and foods 
cooked in fat, nuts, butter, cream, and pastry. 
Thin persons sometimes need special consideration at the 
hands of the physician. They require usually a large amount 
of energy-producing food, such as fats, starch, and sugar- 
containing foods. If they are anaemic, they should have 
foods that contain iron, like eggs and green vegetables. 
Sometimes cod liver oil is prescribed to bring a person up 
to the normal weight. 
Studies made on the subject of weight of body in relation 
to general health and length of life bring out the fact that 
the average weight of persons of 30 years of age if main- 
tained throughout life gives the best condition for all. A 
table of weights for men and also for women of the various 
heights has been prepared, and is recommended as a useful 
guide to follow. OVERWEIGHT AND UNDERWEIGHT 
449 
TABLE OF IDEAL WEIGHTS 
Men 
Height 
Pounds 
Height 
Pounds 
Height 
Pounds 
ft. in. 
ft. in. 
ft. in. 
5 
12(5 
5 7 
148 
6 1 
178 
5 1 
128 
5 8 
152 
6 2 
184 
5 2 
130 
5 9 
156 
6 3 
190 
5 3 
133 
5 10 
161 
6 4 
196 
5 4 
136 
5 11 
166 
6 5 
201 
5 5 
140 
6 
172 
5 6 
144 
Women 
Height 
Pounds 
Height 
Pounds 
Height 
Pounds 
ft. in. 
4 8 
112 
ft. in. 
5 2 
124 
ft. in. 
5 8 
146 
4 9 
114 
5 
3 
127 
5 9 
150 
4 10 
116 
5 
4 
131 
5 10 
154 
4 11 
118 
5 
5 
134 
5 11 
157 
5 
120 
5 
6 
138 
6 
161 
5 1 
122 
5 
7 
142 CHAPTER XXXIX 
TIIE BUILDERS OF BIOLOGY 
Everyone who is interested in Life, observes accurately 
and records his observations correctly is a builder of the 
science of biology. Although the science of biology, as a 
more or less complete body of organized knowledge, is com- 
paratively new, the beginnings 
of it extend back to the time 
of the Greeks. Some of the 
great names connected with 
the upbuilding of biology are 
given in this chapter with 
short accounts of their work. 
Aristotle (384-322 B. C.). 
In history, Aristotle is known 
as the teacher of Alexander 
the Great, and as the leading 
philosopher and scientist of 
his time. In the study of 
plants and animals he was the 
first to point out the absolute 
necessity of knowing the facts 
of structure and development. He also proposed a system 
of classification of animals which was accepted without 
question by later investigators for hundreds of years. 
Aristotle knew a great deal about the development of 
animals from the egg, and held a theory in connection with 
that process which to a certain extent is believed in at the 
present time. He even prepared drawings of many struc- 
Fig. 220. Aristotle. 
450 VESALIUS 
451 
tural features of animals, but these, like the most of his 
three hundred contributions to human knowledge, have been 
destroyed. 
Aristotle expressed incompletely but clearly the idea of 
organic evolution by recognizing and calling attention to 
the gradation of organisms from the lowest to the highest,— 
man. After his time, it was over two thousand years before 
anyone learned more about the process of evolution than 
Aristotle had thought out. In fact, for hundreds of years 
men wrere inclined to inquire first what Aristotle had written 
on this or that topic, rather than to apply the scientific 
method of inquiry which the great thinker himself had 
devised. 
Vesalius (1514-1565 A. D.). Through the long dark 
ages and for a considerable time after the “re-birth of learn- 
ing” in the fifteenth century, no important advance in 
biology w'as made. Vesalius was the greatest of the early 
anatomists. Others before him tried to put the new spirit 
of learning and truth into the study of biology, especially in 
that branch of applied biology known to-day as Medicine. 
Hut Vesalius was the first of the anatomists to break the old 
bonds of authority, and to see things as they really exist. 
Others relied on the writings of Galen (131-200 A. I).) who 
had written on the anatomy of the human body in the second 
century of the Christian era. 
Vesalius was born in Brussels in 1514. Early in life he 
dissected birds, rabbits, dogs, and other animals. He began 
to study medicine in Paris at the age of 18. It is said of him 
that at the third lecture there in the amphitheater of Silvius, 
the professor, Vesalius pushed aside the ignorant surgeon- 
barbers, who in those days were employed to dissect at 
medical schools, and made the dissections properly. 
In later years Vesalius became a professor in the Uni- 
versity of Padua, Italy, where large numbers of students 452 
THE BUILDERS OF BIOLOGY 
flocked to study medicine under him. The greatest wrork 
that has come down to us from Vesalius is his Be Humani 
Corporis Fabrica. In this book excellent drawings of the 
anatomy of the human body artistically done indicate the 
clearness and the truthfulness of the method by which 
Vesalius worked. The scientific method wras thus reestab- 
lished in the domain of knowledge. 
Harvey (1578-1657). The fame of William Harvey 
rests upon the fact that he was the first to apply the experi- 
mental method to physiology. 
His greatest single contribution 
was the discovery of the circu- 
lation of the blood. By a study 
of the structure of the blood 
vessels of the lower animals, 
and by observing the effect of 
placing ligatures on arms and 
legs of living persons, Harvey 
learned that the blood flows in 
a circuit, and that the heart is 
the propelling organ. 
Biologists are inclined to 
consider Harvey, the English 
physiologist, and Vesalius, the 
Belgian anatomist, as among the most important of the 
founders of modern biological science, because of their exact 
methods of work and the fact that their active labor covered 
the two important fields of anatomy and physiology. 
Harvey was born when Shakespeare was fourteen years old. 
Thus they worked at approximately the same time. At 
the age of nineteen Harvey went to Italy to study medicine 
in the University of Padua, having graduated from Cam- 
bridge University (England) in the same year. After four 
or five years at Padua he received a degree called in those 
Fig. 221. William Harvey. MALPIGHI 
453 
days Doctor in Physic. He then returned to England where 
he began to practice medicine and to give public lectures. 
Malpighi (1628-1694). Compound microscopes were 
invented in the seventeenth century. These instruments, 
although very7 crude then, opened up rich fields for discovery 
in the finer structure of plants and animals. One of the most 
famous of the early histologists (scientists studying tissues) 
was the Italian physician Marcello Malpighi. 
Where practically nothing is known, discoveries must 
appear easy for the first investigator on the ground, but 
Malpighi was very skillful in devising methods of observa- 
tion where success would be difficult even with our modern 
appliances. He discovered the air spaces in the lungs of the 
frog, and suggested fairly accurately the position of blood 
and air on opposite sides of membranes. He saw the blood 
corpuscles passing through the fine blood vessels, that is, the 
capillaries. He worked out the finer structures of several in- 
ternal organs in the lower animals and inferred the existence 
of similar structure in man. But the most extensive piece of 
work on a single species was his study of the anatomy of the 
silkworm. This sort of detailed study on a small and some- 
what insignificant creature was a new idea. Even to-day the 
drawings published by Malpighi are considered remarkable. 
Malpighi was born in Bologna, Italy, of well-to-do peas- 
ant parents. He was given the best education the times af- 
forded, but was twenty-one years old before he had made 
up his mind on a career for himself. At about that time his 
parents died. But in spite of the burden of looking after 
seven younger brothers and sisters, he was able to begin 
and carry through his work at the University of Bologna. 
Malpighi served as a professor of the University of Bol- 
ogna, Pisa, and at Messina. Many honors came to him from 
his country and from England for his contributions to science. 
His period of productive labor covered forty years. 454 
THE BUILDERS OF BIOLOGY 
Linnaeus (1707-1778). The great Swedish naturalist, 
Carl Linnaeus, developed and perfected the two-name sys- 
tem of distinguishing the species of plants and animals. The 
naming of plants and animals in the well-known dead 
languages, Greek and Latin, has insured their identity be- 
ing understood everywhere. Besides, the brief and accurate 
descriptions of the species 
that was a part of the sys- 
tem which Litinaeus devel- 
oped enabled scientific men 
to determine whether an ani- 
mal or a plant was a member 
of a species already described. 
If the species on comparison 
turned out to be new to 
science, it could be named 
and described, and its iden- 
tity become a part of com- 
mon scientific knowledge. 
Starting with the species as 
the lowest group of individu- 
als Linnaeus perfected the en- 
tire system of classification 
of living things, bringing out 
in the complicated “System of Nature” the natural kin- 
ships among living things, based upon the likeness or 
unlikeness of structure throughout the great divisions of 
the animal and the plant kingdoms. 
Thus, the work of Linnaeus consisted more in organiz- 
ing and arranging the facts of biological science than in 
contributing new knowledge. But the enormous saving of 
energy and the resulting increase of efficiency in dealing with 
the knowledge about living things under the existing system 
of classification may be faintly imagined if we think what 
would be the task confronting a student who is directed to 
Fig. 222. Carl Linnaeus. CUVIER 
455 
study in a library where the books are stored in piles as they 
happen to be brought from other places. 
In the dignified Carl von Linne, as he called himself after 
being granted a patent of nobility by the King of Sweden, 
it is difficult to recognize the poverty-stricken student at 
the University of Upsala, who mended with paper and birch- 
bark cast-off shoes given him by friends in order that he 
might ultimately obtain his degree. 
Cuvier (1769-1829). Geortres Cuvier, the crreat Freneh 
anatomist, lived at a stage 
in the development of biology 
when there was considerable 
interest in the structure of 
the bodies of animals. But 
he was the first to plan the 
study of the structure or the 
anatomy of the entire animal 
kingdom. This was a gigan- 
tic undertaking, even though 
we understand that he was 
not undertaking the study of 
every species, but merely of 
the typical animals. The im- 
portance of this comprehen- 
sive study undertaken by 
Cuvier made comparison of 
the anatomy of animals on a large scale possible for the 
first time. 
Cuvier was deeply interested in nature from early boy- 
hood. He studied at the academy in Stuttgart, Germany, 
and later went to Paris where at the Jardin des Plantes he 
met many able scientists who gave him great encouragement, 
and whose leader he ultimately became. From a shy, per- 
haps somewhat shabbily dressed provincial youth, Cuvier 
Fig. 223. Georges Cuvier. 456 
THE BUILDERS OF BIOLOGY 
developed into a cultured gentleman with commanding in- 
fluence in the nation. 
Napoleon Bonaparte appointed him director of the higher 
educational institutions of the Empire, and scientific France 
perhaps over-honored him by accepting his teachings against 
the new theory of evolution. 
Bichat (1771-1801). By some authorities on the history 
of biology Bichat, the French histologist, has been placed 
among the first four or five greatest biologists. He lived to 
be only thirty-one, but in that short life accomplished a 
prodigious amount of work of very high order. His work 
was the study of the tissues or groups of cells of the organs 
and the activity of the tissues in health and disease. The 
work he did complemented and extended that of Cuvier, 
and in many respects was more difficult to do. In spite of the 
fact that Bichat studied the finer structure of organs and 
made sketches of the cellular structure, he did not use the 
compound microscope. 
Bichat was born in the Department of the Aisne, France, 
the region of terrible battles in the World War. As a boy 
he was bright and industrious. He went to Lyons to study 
medicine, but the French Revolution forced him to go to 
Paris. There he studied under the great surgeon Desault, 
and later became professor of anatomy. 
Muller (1801-1858). Johannes Muller is credited with 
being the founder of the modern science of physiology, and 
also with being one of the ablest and most magnetic teachers 
in European universities. 
Under Muller physiology was placed on a comparative 
basis. He not only endeavored to bring the knowledge of 
physiology into an organized whole, but he also extended 
it on the basis of experimenting into the allied fields of phys- 
ics, chemistry, and psychology. The methods of physiolo- VIRCHOW 
457 
gists who study problems to-day find their souree in the gen- 
eral method of work and in the faithfulness to truth that 
were so ably begun by Muller. 
Schleiden (1804-1881); Schwann (1810-1882); Schultze 
(1825-1874). The names of Schleiden, the botanist, 
and Schwann, the zoologist, have been associated in biology 
since 1839 in connection with the cell-theory of structure. 
Before their time the nucleus of the cell had been seen, and 
so had protoplasm, but the idea that living bodies are com- 
posed of cells had never been stated. As it was stated finally 
by Schleiden and Schwann it was in some respects incom- 
plete and inaccurate, but corrections were made rapidly by 
other workers who came afterward. 
It was not until 1861, the first year of the Civil War in 
America, that Max Schultze, a very able German zoolo- 
gist, practically completed the definite conception of the 
cell as the unit of structure of all organic things. He demon- 
strated the fact that the cells consist of minute bodies of 
protoplasm inclosing a dense, still more minute mass of 
protoplasm called the nucleus. Schultze pointed out the 
fact that many animal cells have no cell wall. In those 
cases the cells consist of the nucleus with its mass of proto- 
plasm. 
Since the time of these workers, the cell-theory has been 
developed still more until now it includes four phases, as 
stated by Professor Locy, of Northwestern University, “ (1) 
the cell as a unit of structure, (2) the cell as a unit of phys- 
iological activity, (3) the cell as embracing all hereditary 
qualities within its substance and (4) the cell in the historical 
development of the organism.” 
Virchow (1821-1903). Rudolph Virchow, a professor 
in the University of Berlin, spent a long and fruitful life in 
the interests of science, theoretical and applied, and also in 
the political and social welfare of his country. Virchow’s 458 
THE BUILDERS OF BIOLOGY 
chief contributions to biology were in connection with pa- 
thology, or the science of diseased tissues. He was also one of 
the first to state the theory that file material for inheritance 
is contained in the egg and in the sperm of each species. 
Virchow discovered that every cell in the bodies of plants 
and animals is derived from previously existing cells by the 
process of cell-division, thereby correcting errors in the theo- 
ries of earlier workers. 
Pasteur (1822-1895). In front of the Pasteur Institute 
in Paris stands a bronze statue representing a shepherd boy 
trying to beat off a mad dog 
that is attacking two children. 
The statue commemorates l he 
discovery of the antitoxin of 
hydrophobia by Louis Pas- 
teur, the best loved and one of 
the greatest of French biolo- 
gists. The story goes that the 
shepherd boy who was him- 
self bitten while protecting the 
children was brought to Paris 
in an effort to save his life. It 
was impossible to save the 
boy’s life, but the knowledge 
of his heroic conduct coming 
to Pasteur started the great 
scientist on the problem of 
finding a cure for the dread 
disease. This he succeeded in doing, and the erection of the 
Pasteur Institute by popular subscription was one of the re- 
sults. There are now Pasteur institutes in the large cities 
throughout the civilized world. In all of them treatment 
for the bites of mad dogs is applied, and in some, the causes 
of other diseases are studied. 
Fig. 224. Louis Pasteur. PASTEUR 
459 
Pasteur started his scientific career as a chemist. But 
while making some studies on fermentation or souring, which 
was then thought to be due to chemical causes, discovered 
that minute organisms are the actual cause. He discovered 
that the souring of milk and the fermentation of wine, form- 
ing alcohol, are caused by these minute livinv bodies. From 
these discoveries and from 
those made by others, es- 
pecially Koch, of Ger- 
many, and Lister, of Eng- 
land, that new branch oi 
biology, bacteriology, 
came to be created. Bac- 
teriology as a science came 
into being during the pe- 
riod of our Civil War, 
In that same period Pas- 
teur discovered a way of 
combating the insects 
that were destroying the 
vineyards of France. 
About the year 1868 
Pasteur discovered the 
disease that by killing the 
silkworms was destroying 
the silk-making industry 
of Franee. Later his whoh 
effort was directed to the work of ascertaining the causes of 
disease and of producing antitoxins (anti-poisons) for their 
cure. His method was to take some of the disease-producing 
virus from a stricken animal, and pass it through a series of 
stages by permitting the bacteria to grow in mixtures of such 
foods as beef broth and gelatin, thus tending to reduce the 
poisonous effect of the bacteria. Some of this “attenuated” 
virus was injected into a well animal, and the disease in a 
Fig. 225. Jupille. (Courtesy of the 
American Museum of Natural History.) 460 
THE BUILDERS OF BIOLOGY 
mild form would result. But at the same time antitoxins 
would be produced which would guard the animal from 
future attacks of the disease. Pasteur’s first success by this 
method was attained while experimenting with chicken 
cholera. Later he discovered the cause and the cure for 
splenic fever in cattle. In 1885 he discovered the cure for 
hydrophobia. The attenuated virus of hydrophobia is ob- 
tained by giving the disease to rabbits, and taking the 
serum of their blood containing the milder form of the 
disease, injecting it after certain preparation into the blood 
of the human being who has been bitten. The antitoxin 
thus injected is ready to combat and overcome the disease 
germs as they develop from the bite of the mad dog. 
In the Pasteur Institute at Paris various scientific work- 
ers discovered methods of inoculating against diphtheria, the 
bubonic plague, and lockjaw. 
Lister (1827-1912). It seems almost incredible that in 
our day of the general use of antiseptics, such as carbolic 
acid, bichloride of mercury, hydrogen peroxide and iodine 
that up to the year 1867 there was no way of preventing 
death if a wound became infected with gangrene. In that 
year Sir Joseph Lister, a professor of surgery in the Univer- 
sity of Glasgow experimented with the use of carbolic acid 
in the treatment of wounds. He was stimulated in this 
experimentation by the discoveries of Pasteur in the field of 
bacteriology. Lister’s success was immediate, and with the 
perfection of methods of sterilization the name of Lister is 
recorded among the great benefactors of our race, along 
with Pasteur, and with Koch, the discoverer of the cause of 
tuberculosis. 
Lamarck (1744-1829). Some of the Greek philosophers 
believed that living things had not always been as they were 
in their day. But even the most enlightened scientists up LAMARCK 
461 
to the beginning of the Nineteenth Century had not sug- 
gested a theory of evolution or change. Some, like Cuvier, 
believed that the species then existing had always existed. 
Although scientists had recognized the vastness of organic 
change that had taken place in Nature since the beginning 
of time, Jean Baptiste Lamarck was the first to suggest a 
consistent explanation and a 
theory of evolution. 
Lamarck was a botanist, 
but at fifty years of age he 
took up the study of inver- 
tebrate animals as part of 
his work in the Jardin des 
Plantes, in Paris. As he en- 
deavored to classify the spe- 
cies in the collection he no- 
ticed the variations in speci- 
mens from different localities 
and environments. He no- 
ticed also that animals living 
in certain surroundings, and 
having certain needs to meet, 
appeared to have parts and organs marvelously adapted to 
their needs. 
For example, the giraffe can browse on the leaves of trees 
easily because it has a long neck; a duck can swim well, 
because it has webbed feet; a horse can run swiftly because 
it has slender legs and hard compact feet; cave animals and 
underground animals have sightless eyes, as the result of 
their becoming adapted to dark situations. In fact, the 
fitness of organs to their functions seemed to be universal. 
Lamarck was not content with noticing the facts. He un- 
dertook to explain them. 
His explanation was that whatever need arises in the life 
of an animal, it is met by an effort on the part of the animal 
Fig. 226. Jean Baptiste Lamarck. 462 
TIIE BUILDERS OF BIOLOGY 
to adjust itself to the condition. In attempting to adjust 
itself the animal uses certain parts and perhaps neglects, or 
does not need to use, other parts. The parts used will develop 
by lengthening, or becoming stronger, or by changing form. 
The parts not used will become smaller and less significant. 
For example, Lamarck believed that the giraffe’s neck began 
to become longer by stretching to reach leaves, the duck’s 
feet became webbed by using them as paddles in the water, 
and that the moles and cave fishes became blind simply 
through not using their eyes. 
Of course, Lamarck did not maintain that these changes 
took place swiftly or in a definite individual. He did main- 
tain that the evolution of organs occurred by extremely slow 
stages through the effort to adapt being made in many 
succeeding generations, the changes accomplished in each 
generation being inherited by the next. Thus, Lamarck was 
the author of the idea that characters acquired in the life of 
the individual may be inherited and become characters of 
the species. 
For over one hundred years pitched “biological battles” 
have been waged over this proposition made by Lamarck, 
and although the evidence for the proposition is meager, the 
theory has not yet been given up. 
Like a great many other scientific men of an earlier day 
than ours Lamarck as a boy was put to studying for the 
Church. That was in those times considered the chief, or 
the only, professional career for a boy. But like some others, 
Lamarck did not prove to be adapted to that career, and 
finally broke with the parental home. He first went to the 
wars, where he showed the great physical and moral courage 
that became a notable part of his character in after life. 
Lamarck studied at the Jardin des Plantes, and later be- 
came a professor there. When his theory of evolution was 
proposed he became the storm center of a great debate in 
which Cuvier and others attacked his theories with bitter- DARWIN 
463 
ness. Cuvier’s influence was so great that Lamarck was 
generally neglected, and closed his life without receiving 
the homage warranted by his important beginning in the 
theory of evolution. 
Darwin (1809-1882). It has often been said that the 
most powerful book of modern times is Charles Darwin’s 
Origin of Species. The 
influence of the book ex- 
tended far beyond the 
realm of biology, and 
modified the thought and 
method of practically 
every branch of human 
interest and endeavor. 
After the publication of 
the book in 1859 the en- 
tire scientific world felt 
the stimulus of the new 
ideas, and science began 
to command the atten- 
tion of the intelligent 
persons of all nations. 
Darwin’s theory of evo- 
lution as explained in the 
Origin of Species and in 
later writings rested on 
three principles, first, the acts of variation among plants and 
animals, second, inheritance, third, natural selection. The 
facts of variation had been noted by Lamarck who endeav- 
ored to explain them. Daiwin collected and described vast 
stores of facts illustrating variations, but did not attempt 
to explain their cause. He believed that variations were 
inherited, and that to some extent the acquired characters 
are inherited. 
Fig. 227. Charles Darwin. 464 
THE BUILDERS OF BIOLOGY 
Natural Selection was the entirely new feature in the 
development of the theory of evolution. By natural selection 
Darwin had in mind the process by which many variations 
occur in a given environment. Some of the variations will 
be weak or not useful in adapting the organism to its environ- 
ment, others will be strong or “adaptive.” For instance, 
in a litter of foxes some will be weak and be able to obtain 
food with less success than the stronger ones. The latter 
will get more food, and will become stronger. Therefore, 
the chances of their living to reproduce their kind will be 
better than the chances of the weaker animals. This results 
in the selection in nature of the strongest and the most active 
foxes. But there are many kinds of variations that may be 
selected in nature besides those of strength. Color is a fea- 
ture which operates in a very interesting way. There is 
scarcely a species of animal from the highest to the lowest 
that does not profit from the similarity of its color to other 
things in certain situations. The color in most instances 
enables the possessor to escape some danger, but in certain 
instances it appears to aid the captor to approach its victim 
without being discovered. 
Another type of adaptation that falls within the opera- 
tion of natural selection is the kind that manifests degenera- 
tion, and still is adaptive. Examples of this kind are seen 
in the absence of soft appendages in earthworms, and in the 
absence of eyes. The tapeworm living in the intestine of 
the higher animals has neither eyes, nor mouth, nor intestine, 
nor appendages, and for these reasons is admirably adapted 
to its environment. 
On the basis of Darwin’s contributions to science other 
workers have gone on and contributed modifications of its 
principles. Darwin’s principles have been attacked by scien- 
tific men because of the absence of an explanation of varia- 
tion, and also because of the insufficiency of natural selection 
as a means of accounting for evolution,—a theory which no DARWIN 
465 
scientist now denies. In fact, so generally is the validity 
of the theory admitted that it is often called the law 
of evolution. The principal objection to certain phases 
of the theory as stated by Darwin will be given in later 
paragraphs. 
The fact that Darwin himself admitted the incompleteness 
of his own statement of the theory is a sign of one of the 
finest of the traits of character of this the greatest of all 
biologists. Darwin was intellectually honest. He would not 
cover up or ignore a fact when it appeared to conflict with 
an opinion he had held. But he would seek to learn more 
about the truth, no matter where it led him. The picture most 
of us have seen of Darwin represents him as a stern old man 
with patriarchal beard. But he was one of the kindest and 
most generous of men, not only in his family life, but even 
with the enemies he made on account of his startling 
theories. 
Some of these enemies were scientific men; others were 
leaders in the Church. The latter held out in opposition 
the longest, because they were convinced that the Darwin- 
ian theory threatened to undermine belief in religion. Never- 
theless, with the progress of general understanding, the leaders 
of the Church for the greater part relented, and now teach 
evolution as a proved law of life, applying even to religion 
itself. 
Darwin as a boy tried to study medicine, but found it 
very dull, and then went to Cambridge University to pre- 
pare for the ministry. But before taking his degree he be- 
came much interested in science. 
At the age of twenty-two he was accepted as naturalist 
on H. M. S. Beagle, a war vessel that was about to make 
a cruise of five years’ duration around the world. On this 
journey Darwin collected an enormous number of facts 
before the idea of change in the organic world became a 
conviction with him. In fact, like Lamarck, in the early 466 
T1IK BUILDERS OF BIOLOGY 
]>art of his study he believed firmly in the unchangeableness 
of the species of plants and animals. 
Soon after Darwin’s return to England he bought an es- 
tate out of an abundant inheritance, and retired there to 
begin his eventful life of collecting more facts, experimenting 
and thinking. From the time Darwin first became convinced 
of the truth of evolution, in 1837, he studied twenty-two 
years until in 1859 he published the famous book, The 
Origin of Species. 
Curiously enough when Darwin was about to publish his 
book, he received from the English traveler and biologist, 
Alfred Russell Wallace, an article which contained an ex- 
position of exactly the same important idea of evolution, 
worked out in another part of the world. Friends of the 
two workers arranged to have abstracts of the idea as given 
by them presented before the Linmean Society of London 
in 1858 at the same time. 
Darwin was born in the same year as our martyred Pres- 
ident, Abraham Lincoln, (1809) and died in 1882. During 
the last forty years of his life he worked under the handicap 
of ill-health, which was caused probably by eye-strain. A 
monument to the memory of Darwin has been erected in 
Westminster Abbey, London. His power in the field of all 
knowledge will be everlasting. 
Agassiz (1807-1873). Jean Louis Rodolph Agassiz is 
best known as a great teacher of zoology, especially as the 
teacher of many biologists of America, some of whom were 
still living and working at the time of the publication of 
this book. Everyone who has studied under Agassiz testifies 
to his inspiring leadership as a teacher and to the wonderful 
enthusiasm and productiveness of the man as a scientist. 
He was a great man and a warm friend in a circle of the 
great men of Boston and Cambridge, Mass., in the period 
of our Civil War. On the fiftieth anniversary of his birth AGASSIZ 
467 
he was given a dinner by these friends. One of them, the 
poet Longfellow, composed and read for the occasion “The 
Fiftieth Birthday of Agassiz,” which may be found in the 
Birds of Passage series of poems. One stanza reads, 
“And he wandered away and away 
With Nature, the dear old nurse, 
Who sang to him night and day 
The rhymes of the universe.” 
Agassiz did not become a resident of our country until 
be was thirty-nine years of age. He was born in Switzer- 
land. His first important 
scientific work was on fresh- 
water fishes. Later he stud- 
ied fossil fishes and proposed 
a new classification for them. 
Although the amount of work 
he did on the fishes was prodi- 
gious, he carried on and com- 
pleted monographs on the 
fossil echinoderms and on the 
fossil mollusks. 
When he was twenty-nine 
he branched out into a new 
field. He became interested 
in the phenomena of the 
movement of glaciers. In or- 
der to study glaciers contin- 
uously he built a hut on the Aar Glacier. He came to the 
conclusion that the whole of Switzerland was at one time like 
Greenland is now, covered with gigantic and deep rivers of 
ice which strewed boulders everywhere on the sides of the 
mountains. Later, in Scotland he discovered the undoubted 
evidence of a glacial epoch during which time a sheet of ice 
must have covered the north of Europe. 
Fig. 228. Jean Louis Rodolph 
Agassiz. 468 
THE BCILDERS OF BIOLOGY 
Agassiz’s interest in visiting America was partly due to 
his desire to study the extent ot' glacial action here. In 1840 
he came and delivered a series of lectures in Boston. The 
following year he was elected professor in Harvard Univer- 
sity. He carried on extensive work in geology and zoology 
in America with the aid of many assistants. He made ex- 
plorations to Brazil to study fishes, and built up the Museum 
of Comparative Zoology at Harvard, the best university 
museum in the country. 
Near the end of his life, Agassiz founded a school of re- 
search on the Island of Penikese, in Buzzard’s Bay, where 
the spirit of scientific investigation of marine life enthused 
many American biologists who were fortunate enough to 
come under the influence of the great teacher. One of the 
surprising facts of Agassiz’s career is his opposition to the 
Darwinian theory. He was one of the last of the great 
leaders in biology to oppose it. Agassiz died in 1873 and 
was buried in Mount Auburn Cemetery, near Boston. His 
monument is a great boulder brought from the Aar Glacier 
near the spot where his hut stood. 
Huxley (1825-1895). Professor Thomas Henry Huxley, 
the English biologist, exerted an important influence on 
critical methods of investigation in the morphology or struc- 
ture of animals as well as in their physiology. But, unlike 
most scientific men, he appeared often before the public 
to deliver addresses. Then his keen intellect, his brilliant 
wit, and his magnetic personality gave effective support to 
any scientific controversy or public cause he believed in. He 
was the knight-errant of evolution. In the period of gen- 
eral antagonism stirred up by the Origin of Species, Hux- 
ley battled formidably with opponents on the public plat- 
form and in public print. 
Like Darwin, Huxley was a man of thorough intellectual 
honesty. While defending the theory of evolution on general HUXLEY 
469 
grounds, he pointed out what he believed to be errors in the 
work of Darwin. For example, he did not believe that new 
species developed by the inheritance of small variations, 
but rather by the inheritance of large variations or “leaps.” 
A great deal of support for this opinion has since developed. 
Huxley was interested in many public movements. He 
was at one time a member of the London School Board, and 
at that time gave to the public some important criticism of 
the school studies. Huxley’s influence on the teaching of 
biology in secondary schools 
is undoubtedly greater than 
that of any other man. 
While Darwin was born of 
well-to-do parents, Huxley 
was the son of poor parents, 
and was not given the chance 
to go to school, and was not 
encouraged intellectually un- 
til he became a man. But by 
his own effort he got hold of 
scientific books and educated 
himself. At seventeen he be- 
gan to study medicine at 
Charing Cross Hospital, Lon- 
don. After receiving his de- 
gree he went as surgeon on 
II. M. S. “Rattlesnake” to Torres Strait to survey. He was 
on this journey four years. During that time he collected and 
studied great quantities of material from the sea. For many 
years afterward he drew upon that rich store for facts new 
to science. Later he gave much time to the study of fossils. 
From these two sources his most important contributions to 
publications were made. Perhaps the best known of Hux- 
ley’s public addresses is Mans Place in Nature, a very fas- 
cinating and illuminating essay. 
Fig. 229. Thomas Henry Huxley. 470 
THE BUILDERS OF BIOLOGY 
Weismann (1834-1916). August Weismann, the German 
biologist, gave the early part of his life to zoological investi- 
gations at the University of Freiburg. He studied and wrote 
about the development of the Diptera, known as the order of 
flies, and did a great deal of work on other groups of animals. 
Trouble with his eves at times caused him to turn his atten- 
tion to the problems of descent, 
especially that of heredity. 
Weismann was a keen critic, 
a master of details, and a 
thinker with rare powers of or- 
ganizing his facts and marshal- 
ing them into a consistent 
whole. But he was intensely 
speculative, and ranged into 
fields where his opponents main- 
tained his suppositions could 
neither be proved nor dis- 
proved. Nevertheless, the 
career of Weismann has been 
extremely useful in helping to 
clear up some vexed questions 
in the Law of Evolution. 
Weismann showed that the qualities transmitted from 
generation to generation in every species are carried by the 
minute bodies called chromosomes in the nuclei of the cells. 
In those animals and plants which reproduce by the sexual 
method the reproductive cells—the egg cells and the sperm 
cells—the chromosomes form the special “germ-plasm” 
which is the only material containing the characters for 
transmission. Furthermore, the reproductive cells are the 
only ones that pass from one generation to the next, and 
hence are the only ones that could carry the inheritance 
which continues forever. This fact gave rise to the expres- 
sion, “the continuity of the germ-plasm.” 
Fig. 230. August Weismann. 
(Photo from Keystone View Co.) MENDEL 
471 
Whereas Darwin believed that it was possible for char- 
acters or the effect of experience acquired by the individual 
during its life to be transmitted to the next generation, 
Weismann denied the possibility of anything of the kind 
taking place. As evidence of this he maintained that the 
experiences of the individual could reach only the soma or 
body cells, since they only are exposed to the effect of these 
experiences. He maintained that there is no way by which 
the effects in the soma cells may reach the reproductive cells. 
The group of biologists who are classed as Neo-Darwinians 
believe with Weismann that acquired characters cannot be 
inherited. 
Weismann believed strongly in the principal of natural 
selection as stated by Darwin, except that he speculated 
further and maintained that there was a natural selection 
going on among the elements of the chromosomes of the re- 
productive cells themselves. He thought all variations took 
place there and that the best fitted to survive were selected 
and gave certain qualities to individuals that developed from 
the varying elements. 
Weismann’s last great work was The Evolution Theory, 
published in 1904. He died in 1916, in the period of the 
World W ar. 
Mendel (1822-1884).——In the Middle Ages practically 
the only men of scientific attainments were attached to 
the priesthood of the Church. But in modern times, with 
the increasing specialization in learning, few men can give 
their attention to more than one field of endeavor. How- 
ever, Gregor Mendel, an Austrian monk, found time to carry 
on experiments in heredity that have caused his name to be 
placed conspicuously on the roll of honor in biology. 
In 1866 Mendel published papers which gave to the world 
some new and important discoveries. But the principles 
then discovered were overlooked by scientific men until 472 
THE BUILDERS OF BIOLOGY 
1900 when they were rediscovered by De Vries, the Dutch 
botanist. Bateson, the English zoologist, then found the 
original publications of Mendel and made them known to 
the world. Mendel experimented with growing common peas. 
The flowers of pea plants if left to their own development 
will pollinate and fertilize themselves. Mendel crossed one 
variety of form or color with another variety of form or color. 
When the seeds produced by 
this crossing matured they were 
planted the next year, and their 
progeny kept under observation 
for two or more generations. 
Mendel found that when a 
tall form of pea was crossed 
with a dwarf form all of the 
plants of the next generation, 
were tall. But if the flowers of 
the second generation were per- 
mitted to fertilize themselves, 
the seeds would produce in the 
next or third generation some 
tall plants and some dwarf 
ones. The character tallness was apparently the only one 
of the two present in the second generation, but further 
breeding showed dwarfness also to be present. Mendel 
called tallness in this experiment the dominant character, 
and dwarfness the recessive character. 
In the third generation another curious fact was that the 
number of dwarf pea plants was just one-fourth of the entire 
number. When the dwarf ones were bred they remained 
dwarf through as many generations as they were carried. 
When the remaining three-fourths, the tall ones, were bred, 
one-third of them (one-fourth of all) separated out as tall 
plants, and gave rise to other tall ones continuously. In 
each generation there were one-half of the entire number 
Fig. 231. Gregor Mendel. GRAY 
473 
that in the next generation gave rise to one-fourth dwarf 
and three-fourths tall. 
This mathematical relation is due to the chances of the 
reproductive cells to unite. There are just the same num- 
ber of chances of a “tall” reproductive cell uniting with an- 
other “tall” cell as there are of its uniting with a “dwarf” 
cell. These chances are expressed in the following alge- 
braic formula: 
TT + STD + DD 
(1+2 +1) 
Mendel experimented on the inheritance of the smooth 
and wrinkled character in pea seeds, and also on the inheri- 
tance of color. The theoretical importance of Mendel’s 
discoveries is that it shows that the reproductive or germ 
cells carry only one character of a particular kind; that is, 
they bear only the tallness or the dwarfness, and not both, 
although they bear other single characters of other kinds. 
The practical value of his work and of a great mass of work 
done on plants and animals since Mendel’s time is that we 
now have a method by which new varieties can be produced. 
We also know when we may expect a variety to breed true, 
and why it breeds true. 
Gray (1810-1888). Asa Gray was born in Oneida County, 
New York. From early boyhood he was an incessant reader. 
At the age of sixteen he began the study of medicine. lie 474 
THE BUILDERS OF BIOLOGY 
took his medical degree in his home county before he waS 
twenty-one. 
In the period of his study of medicine he became interested 
in botany. He collected a great many plants, and “ran 
down” their names. Accounts of his life make no reference 
to Gray’s practicing medicine. Instead, he soon became a 
professor of natural science, which in those days meant teach- 
ing every branch of science, in a 
small school in Utica, N. Y. He 
continued to collect botanical 
specimens. He taught and pub- 
lished his researches, some in 
botany, and some in mineralogy. 
His method of work was to 
be careful and painstaking. He 
carried on an extensive corre- 
spondence with scientific men, 
and supplied some with new 
specimens. Many years later, 
in his days of distinction, he 
came upon specimens in Euro- 
pean collections which he had 
prepared and sent to correspondents in early days. 
At the age of twenty-six he was appointed Curator of the 
Lyceum of Natural History in New York. At twenty-eight 
he was appointed professor in the University of Michigan. 
At thirty-one he was elected to be professor of natural his- 
tory at Harvard University, receiving a salary of $1,000 a 
year! At Harvard he established the well-known Botanic 
Garden, and began a long and distinguished career as the 
leading botanist of America. His several text-books became 
standard works everywhere, and his researches were classics 
in their field. He quickly caught the meaning of the new 
theories in evolution when Charles Darwin published the 
Origin of Species in 1859. His studies in plant life were 
Fig. 232. Asa Gray. GALTON 
475 
available to Darwin in the published accounts, as well as in 
voluminous correspondence with the great English biologist. 
In the elderly gentleman of Figure 232 it is difficult to 
recognize the alert and intense young man of an earlier period. 
His biographer says that in the street he was usually on a 
half run, as if impatient to reach his work again. When 
traveling by coach and climbing a hill, he would sometimes 
spring through an open window to secure a plant. He was 
quick and impetuous, and his prevailing spirit was of in- 
exhaustible good nature. 
De Vries (1848- ). Hugo de Vries, the Dutch bot- 
anist, an active and able experimenter still living at the 
time of the publication of this book, has made observa- 
tions in the Botanic Garden in Amsterdam on the varia- 
tions appearing in the evening primrose. He finds that new 
species seem to rise suddenly by the appearance of a new and 
considerable change in structure. These large changes he 
calls mutations. He believes that species have risen solely 
by the appearance of series of mutations. The mutations 
are fixed by natural selection. Thus De Vries believes in 
the principle of natural selection, but denies the validity of 
Darwin’s idea that species arise by the gradual accumula- 
tion of minute variations. It will be remembered that Hux- 
ley used an expression, “jumps,” which means the same thing 
as is implied by “mutation.” The probability is that both 
large and small variations operate in the formation of species. 
But we shall know more about it when future biologists 
carry on experiments as carefully as has De Vries. 
Galton (1822-1911). Sir Francis Galton was another 
important contributor to our knowledge of inheritance. He 
was especially interested in the applications of laws of hered- 
ity to the human race. Galton was the grandson of the poet 
naturalist, Erasmus Darwin, and a cousin of Charles Darwin. 476 
THE BUILDERS OF BIOLOGY 
Galton combated the theory of the inheritance of ac- 
quired characters. His work was valuable because like 
Mendel he tried to reduce the study of heredity to a mathe- 
matical basis. The movement which he started in this line 
still continues, and has extended to the application of mathe- 
matical measurements to the distinction between species. 
The phase of Gal ton’s 
work which is of the 
greatest social impor- 
tance is in the new ap- 
plied biological science 
to which he gave the 
name “Eugenics.” This 
means the science of be- 
ing “well born.” This 
science is now exten- 
sively studied, and much 
legislation in Europe and 
America has resulted 
from the movement 
started so ably by Galton. 
Our study of human 
inheritance has shown us 
that certain defects of 
body and mind are sure 
to be inherited, some as 
dominant, others as rescessive characters. The eugenists 
have convinced society that legal means should be taken to 
prevent persons suffering from certain foul diseases, and 
those of imbecile minds, from marrying. Our race must be 
protected from dangerous defects now existing. Otherwise, 
the whole race will tend to become degenerate. 
If there were no other practical application of biology 
than eugenics, the value of the science of life to humanity 
would be evident to the minds of all thinking persons. 
Fig. 233. Sir Francis Galton. 
(© Keystone View Co., Inc., N. Y.) BIKROIGHS 
477 
It is worth while to know that the science of biology is in 
a continuous process of development. Not all the essential 
facts have been discovered, and there are still important in- 
terpretations or explanations that will come with future 
thinking. Interest in the problems of life is very great among 
persons in general, of course, and deep enough for many 
persons to form the base 
of the activities of a life- 
time, even in our modern 
times, when the world is 
full of interests that nevei 
existed in former gen 
erations. 
Burroughs (1837-1921).- 
.John Burroughs was i 
different kind of biologisl 
from the others whose 
work has been describee 
in this chapter. He stud 
ied at no university. He 
had no training under i 
specialist of any kind, an< 
he left no record of tech 
nical work accomplished 
such as the other biolo- 
gists left. Yet, Bur- 
roughs has probably done more than all of them to inspire the 
young and the grown-ups also, with a deep and lasting love 
of nature. This inspiration was transmitted through simple, 
life-like and charming description of all things and conditions 
out-of-doors. Thorough familiarity with facts, and boyish 
enthusiasm about everything gave Burroughs a greater fol- 
lowing, perhaps, than any writer on nature topics ever had. 
Jolm Burroughs was born in Roxbury, in the Western Cats- 
Fig. 234. John Burroughs. 
(Courtesy American Museum of Natural 
History.) 478 
THE BUILDERS OF BIOLOGY 
kill Mountains, in the State of New York. His father was a 
farmer, and the son also became a farmer, varying that 
career with teaching a country school during his young man- 
hood. From early boyhood he liked the out-of-doors, the 
farm life, the hunting and the fishing. 
At the age of twenty-three, he sent an essay he had written 
on a philosophic topic to the Atlantic Monthly. The editor, 
James Russell Lowell, at first thought it had been “cribbed” 
from Ralph Waldo Emerson, so closely did it resemble 
Emerson’s style. But the article was genuine and was ac- 
cepted. The somewhat formal style of writing was later put 
aside, and the simple style of familiar description taken up. 
With this he was immediately successful. 
The “Rip Van Winkle Country” of the Catskills was 
known throughout to Burroughs. He had tramped over 
most of it, had fished, hunted and ridden through it so many 
times that to those who knew him in the long years of his 
leisurely but productive life, he was in reality as much a part 
of the character and charm of those low-lying, tree-covered 
mountains as was Washington Irving’s hero himself in 
fiction. 
Of course, everyone knows Rip Van Winkle. Not so many 
know the Catskills themselves. It may be that fewer still 
know well the writings of John Burroughs. But for those 
who have known all three, and in addition the personality of 
John Burroughs, there is a wealth of charm and spiritual 
satisfaction. 
Near the close of his life Burroughs prepared this message 
to be published in his biography: 
“My dear Young Friends: 
The most precious things of life are near at hand, without 
money and without price. Each of you has the whole wealth of 
the universe at your very doors. All that I ever had, and still have 
may be yours by stretching forth your hand and taking it. 
John Burroughs.” CHAPTER XL 
THINGS AND CONDITIONS THAT HOLD US BACK 
A Toppling Monarch. The World War of 1914-1918 
marked the beginning of the fall of monarchy in the world. 
None of the monarchs of history has ruled his subjects 
more tyrannically than has the longest-lived of them all, 
—King Alcohol. By a peculiar irony of fate that follows 
monarchs, and makes them disciplinarians of one another, 
the greatest human monarch on the eve of his own down- 
fall decreed that vodka should no longer be made in the 
Russian Empire. That act of Emperor Nicholas was recog- 
nized the world over as the beginning of the end of the 
power of drink. The abolition of the manufacture of 
absinthe in France, and the governmental control of the 
manufacture of alcoholic beverages in England and America 
were blows at the liquor traffic which followed naturally. 
When the abolition of the traffic became a political issue 
in the United States about the year 1880, the “Prohibition- 
ists” were regarded as narrow-minded meddlers with “per- 
sonal liberty.” The Woman’s Christian Temperance Union 
also came in for its share of social obloquy. Doubtless, 
there were “cranks” in both organizations, and so there 
were in the political party that forced the abolition of 
slavery before the country as a national issue in 1856. 
Although the Prohibition Party had never polled a vote 
that either of the two great parties had reason to fear, 
nevertheless, the sentiment for prohibiting the manufacture 
and the sale of alcoholic beverages in the United States 
grew at a rapid rate. First Maine and Kansas, and then one 
Southern state after another passed prohibition amendments 
479 480 
THINGS THAT HOLD US BACK 
to their constitutions. By 1919, the required three-fourths 
of the states of the Union had approved the eighteenth 
amendment of the Constitution to prohibit the manufacture 
and the sale of intoxicating beverages in the United States 
for other than scientific and medicinal purposes. 
Many of the largest public service corporations in the 
country have for some time refused to employ men who are 
addicted to the use of liquor. The interest of a railroad 
company in the habits of its employes does not rest on a 
moral basis, as might be the case with the interest of a city 
or a state in the welfare of its citizens. The concern of the 
company is purely economic. If it can establish a reputa- 
tion for a small number of accidents in the running of trains 
and in construction operations, it will increase its business 
in competition with other companies. It has been shown in 
the experience of operating and construction companies of 
many kinds that men who are given to the use of liquor 
suffer from accidents, or are the cause of accidents more than 
are men who do not have this habit. The fact that accidents 
destroy property" is an extra stimulus to reducing their fre- 
quency. Many companies that have been able to increase 
their efficiency in this way offer better wages than do other 
companies doing the same kind of work. 
The interest of the nations at war in restricting the liquor 
traffic was connected closely with the efficiency" and the 
dependability of the men in the trenches, and with the 
bearing of the manufacture of liquor on the food supply. 
Nations at peace find their chief interest in the bearing the 
traffic has on the prevalence of crime and poverty. Public 
service corporations are influenced by" the desire for efficiency 
and for the development of their financial power. Two 
other branches of organization that have made up their 
minds on the effect of the consumption of alcoholic beverages 
on human beings are the life insurance companies and the 
physiologists, the scientific experimenters in nutrition. The A TOPPLING MONARCH 
481 
interest of life insurance companies in the prevalence of the 
drink habit is connected with their desire to reduce to terms 
of scientific accuracy the chances of life and death of the 
persons they insure. The interest of the scientific experi- 
menters in food values is connected with their desire to 
ascertain and to publish the truth. 
An investigation made by a medico-actuarial committee 
studying the records of forty-three American life insurance 
companies ascertained that the mortality among “steady, 
moderate drinkers was 86 per cent greater than the average” 
for their several ages, and that of those who had a history 
of occasional alcoholic excesses, the mortality was “fifty 
per cent greater than the average” for their several ages. 
Those men who had taken two glasses of beer, or a glass of 
whisky, or their alcoholic equivalent each day, showed a 
mortality 18 per cent greater than the average. In all of 
these groups, the death rates from Bright’s disease, pneu- 
monia, and suicide were higher than the average. Following 
the discovery of facts like these, the life insurance companies 
establish groups of “risks” in which persons having a given 
set of habits or physical states are placed, and then are re- 
quired to pay a higher rate for their insurance. Of late years 
some of the companies refuse to accept the applications for 
policies made by persons whose lives are uncertain because 
of their vicious habits. 
The effect of alcohol on the human body has been studied 
scientifically by competent physiologists all over the world. 
About the year 1900 some American physiologists believed 
that alcohol could be called a food correctly and a proper 
stimulant to be used medically in certain cases. A great 
deal of investigation since that time has served to change 
that opinion, and to convince physiologists that alcohol is 
not a food in an accurate sense, and is not a stimulant at 
all. but is a dangerous narcotic. The number and the extent 
of the risks one takes in becoming addicted to the use of al- 482 
THINGS THAT HOLD US HACK 
cohol are so appalling that when our citizens become thor- 
oughly informed about the subject, it is altogether likely 
that the doom of the traffic will be well-nigh complete, even 
“for medicinal purposes.” The consummation of the end, 
however, must depend on the facts. They are as follows: 
The carbon in alcohol is oxidized and releases some energy, 
but the amount is small and of no consequence. As was ex- 
plained in Chapter XXXVI there are certain autonomic nerve 
Fig. 235. Guinea Pig. 
(Courtesy of Professor W. E. Castle.) 
centers which set organs into activity. Now, alcohol is one 
of the substances that paralyze the controlling nerve centers 
of the heart. In this way “the brake is taken off the heart,” 
and that organ begins to “speed up” its movements, thus 
giving to the early scientific observers the impression that 
the action of the heart was really stimulated. It is also 
known that while the pulse beat is more rapid under the in- 
fluence of alcohol the force of the beats is less, implying that 
the amount of blood sent through the arteries is not increased 
as was formerly supposed. These results obtained by ex- A TOPPLING MONARCH 
483 
perimenters in German universities have been verified by 
investigators working in the Nutrition Laboratory of the 
Carnegie Institution. The investigators agree that alcohol 
is a narcotic, a depressing drug, even in the smallest doses 
usually taken as a beverage. 
It has been ascertained by the investigators in the Car- 
negie Institution and elsewhere that the time required to 
act on a stimulus or suggestion given a man is increased 
after a small dose of alcohol. Simple intellectual processes 
are retarded, and the memory is impaired. 
Observations have been made on the resistance to disease 
of which persons given to the drink habit are capable, and 
it has been found that the paralyzing of the white blood cor- 
puscles is one of the causes of their lowered power of re- 
sistance. Some of the special forms of infectious diseases 
which are more serious for drinkers than for others are 
pneumonia, tuberculosis, typhoid fever, blood poisoning, 
cholera, and hydrophobia. 
Professor C. R. Stockard of the Cornell Medical College, 
New York, has carried out experiments on exposing guinea 
pigs to the fumes of alcohol for a certain period each day 
for years. Whatever conclusions he could draw would have 
a certain bearing on man, for the nature of the living sub- 
stance, protoplasm, is much the same anywhere. Treated 
guinea pigs often showed an opaque appearance of the 
cornea, the tough, transparent coat of the eye. Some be- 
came blind during the treatment. But examination showed 
no abnormal condition of the internal organs. Nevertheless, 
the offspring of a parent that had been treated with alcohol 
showed seriously diseased conditions. The chief defects were 
manifested in the central nervous system. Many young 
animals had nervous tremors. The hind legs, the fore legs, 
or both legs on one side would be paralyzed. In some animals 
the eyes were blind. Or there would be present one eye only, 
or none at all, even the eyeball and the optic nerve being 484 
THINGS THAT HOLD ITS BACK 
absent. The number of young guinea pigs tended to de- 
crease*. These defects persisted in at least three generations, 
although none after the first were exposed to the fumes of 
the alcohol. In fact, the great-grandchildren of the al- 
coholized parents “ almost without exception are incapable 
of reproduction, and are in many ways subnormal and de- 
generate.” 
Obviously the effect on the protoplasm of guinea pigs is 
more serious than it is on the protoplasm of man, when the 
inheritance is considered. It may not be correct to say that 
the internal organs of guinea pigs are not directly affected 
by the alcohol as was stated above, until it is possible to 
compare the physiological and psychological effects on the 
guinea pigs with the effects as we know them in man. It 
may not be possible to make this comparison. In any event, 
the experiments on the guinea pigs are impressive. 
There are some men of talent and understanding who freely 
acknowledge the validity of the principal charges in the 
indictment against King Alcohol. But they maintain also 
that in spite of all that has been shown, he has given the 
world much that is beautiful and wonderful in song and in 
literature. Besides, they say, the simplicity, charm and 
frankness of many personalities would be concealed from 
their friends forever, if it were not for alcohol. 
In terms of the physiology of the nervous system under 
the influence of alcohol, we now understand that when “the 
brake is taken off the brain” the creative imagination of a 
genius may conceivably produce work that is unusual and 
truly wonderful. These are possible results. There are few 
evils that do not occasionally yield a beneficial result. But 
we have only to sum up the results all along the line, and 
consider whether in all the possible artistic and literary 
product of men of genius much of the same kind of product 
has not been actually lost through the paralyzing effect of 
alcohol. We must not forget that qualities of this kind A TOPPLING MONARCH 
485 
that have been lost are never seen, and hence are not likely 
to be thought of. 
It is well for us to consider why after men understand the 
serious results of using alcohol they still continue the cus- 
tom. In a measure the answer is that a drug habit has 
been formed which the person finds difficult to break. With- 
out question many men drink because they believe it paves 
the way for greater sociability, for having what is called 
a “good time,” but chiefly because alcohol makes them 
forget the “hum-drum,” or the worry, or the poverty of 
their lives. 
Those who are fighting intelligently to destroy the liquor 
traffic should not forget that a strong point in the attack 
would be to aid also in the abolition of the conditions which 
exist as a constant menace to inducing men to drink. As was 
pointed out in the chapter on “Up from Savagery” we must 
endeavor to make it possible for every human being to have 
enough of the product of his labor to keep him in health and 
reasonable plenty. Besides, social conditions must be im- 
proved in every way, so that a man may find his home and 
the normal processes of living a comfort and a source of 
natural happiness. Furthermore, our system of education 
must be improved to give every person natural thoughts 
beyond the “hum-drum” of a stupid life of personalities. 
We must be taught to live outside our individual selves and 
to become a part of all nature, which is always interesting. 
It is absolutely wrong and destructive that a human being 
should be so surrounded by misery that he must take on a 
villainous habit in order to get away from himself and his 
environment. 
With all the important work that has been done to destroy 
the King, it is most important that his former subjects should 
be provided with a new and finer substitute for their loy- 
alty,—their own self-respect, and the welfare of their fellow- 
men. 486 
THINGS THAT HOLD US HACK 
The Drug Menace. In addition to the burden of alcohol 
upon us, there is an evil which is even more insidious in its 
operations than is alcohol, and that is the other, more terrible 
habit-forming “drugs.” The best known of these are the 
preparations and the derivatives of opium (morphine com- 
pounds). Less well-known habit-forming agents, intro- 
duced chiefly for medicinal purposes are cocain, acetanelid, 
acetphenetidin, antipyrin, phenacetin, caffein, cannabis indica, 
chloral hydrate, saccharin, codein, dionin, and heroin. The 
last named is one of the most terrible in its effects and its 
hold upon its victims. 
It is estimated that there are over 1,000,000 drug addicts 
in the United States. Everyone of these persons lives in 
unnecessary and avoidable misery. Naturally, there are 
groups of individuals wTho are desirous of preying upon their 
fellowmen if the opportunity offers. These persons engage 
in the surreptitious sale and distribution of the drugs, in 
spite of laws forbidding the traffic. Many of the medicinal 
products containing the drugs are sold legally over the 
counters in drug stores. For this the drug stores are not 
primarily responsible. The people are responsible for per- 
mitting the manufacture of the patent medicines of that 
kind. 
Sometimes physicians prescribe the drugs in cases seeming 
to require it. After recovery the patient may continue the 
use of the medicine on account of the apparent good effect. 
Thus the habit of using the drug is liable to be fastened on 
the patient, and he becomes one in reality practically 
throughout life. In the state of New York and in a few 
other states the law nowr requires physicians to make pre- 
scriptions for every filling of a bottle by the pharmacist, 
when habit-forming drugs are part of the ingredients. This 
helps to prevent the patient from continuing the use of 
the substance at his ow n pleasure. 
Another way in which habits of this kind are formed is THE DRUG MENACE 
487 
by the practice of giving “soothing syrups” to babies. By 
many mothers Mrs. Winslow’s Soothing Syrup has been re- 
garded as a great “blessing,” but that was because the 
mothers did not know what the medicine was doing to their 
children. This preparation contains morphine sulphate in 
quantity sufficient to quiet a child through the narcotic 
action of the drug. No mother when she understands would 
deliberately give her child morphine. Other soothing syrups 
may be offered as substi- 
tutes for the old one that 
is nowadays condemned, 
but they also contain 
drugs of the same nature 
and effect, either mor- 
phine itself, or codein, or 
chloroform, or chloral hy- 
drate, or cannabis indica, 
or heroin. Happily, with 
the new knowledge of the 
caring for babies the 
mother does not need to 
try to keep the baby quiet 
at all times. Sometimes 
crying is good exercise 
for it. 
Most persons who pat- 
ronize the places where 
soft drinks are sold do not realize that danger lurks there. 
Many of the products there contain caffein, the narcotic 
found in coffee and in the kola nut, or extracts of cocoa leaves. 
This principle of cocoa leaves is cocain, one of the most in- 
sidious and dangerous of drugs. The advertised value of 
drinks containing these materials is that they give relief from 
fatigue. Many persons are addicted to the use of medicated 
soft drinks. These persons are properly classified as drug 
Fig. 236. Alcohol Comparisons. 
(Poster of the American Medical Asso- 
ciation.) 488 
THINGS THAT HOLD US HACK 
addicts. The step to their absolute dependence on the drugs 
would be a short one for them. 
Many persons suffering from the chronic diseases of 
asthma, catarrh, tuberculosis, and epilepsy, and also from 
periodic colds and headaches purchase patent medicines that 
contain these habit-forming drugs. It is unfortunate that 
society has not yet been stirred to realize that patients 
suffering from disease naturally try to obtain relief from 
any and all sources that appear to be available. The bill 
for patent medicines is a large one, but the indictment 
against us for ignorance and the punishment for our social 
neglect are still more serious. We need to have more in- 
formation spread among all classes of persons, and after 
that there should be a more definite determination on the 
part of organized society to eliminate the unnecessary evil 
of preying drug habits. In their stead let us try to establish 
greater confidence in the scientific cure and eradication of 
disease. Drugs not only create unnecessary misery, but 
they also hold us back from race accomplishments greater 
than we may be able to conceive. 
The Smoking Nuisance. Prior to the sixteenth century, 
the use of tobacco was confined to the American Indians. At 
about that time Jean Nicot, the French Ambassador at 
Lisbon, Portugal, introduced snuff-taking in the Court of 
Catherine de Medici. The habit of smoking soon began 
to spread rapidly throughout Europe. Whatever men may 
say about the taste for alcohol being natural because the 
existence of alcoholic liquors may be traced far back in 
history, they cannot say it of tobacco. 
There has never been the powerful campaign made against 
the use of tobacco that has been made against alcohol, al- 
though in the early days of the introduction of tobacco in 
Europe the governments endeavored to oppose its use. Cer- 
tain influences in America have organized to fight the habit THE SMOKING NUISANCE 
489 
of using tobacco, and certain states forbid the sale of ciga- 
rettes to boys under sixteen. But the use of tobacco is on 
the increase, especially in the form of cigarettes. 
Tobacco contains a narcotic poison, called nicotine in 
honor of .Jean Nicot. A number of other organic chemical 
compounds are found in tobacco, chiefly pyridin, and furfural. 
All these are very poisonous, and if they were taken even in 
HE WON’T LAST LONG AFTER THE SUN GETS UP 
Fig. 237. Consumption “Cures.” 
(Poster of American Medical Association.) 
small quantities in their pure form would quickly prove fatal. 
Many experimental observations have been made.of the 
effect of tobacco on the human being. In 1912 an investiga- 
tion was made on the effect of the smoking habit on the 
candidates for membership in the football squads in six 
colleges. In every case the percentage of those actually 
achieving positions on the team was much greater for the 
non-smokers. In the same investigation non-smokers stood 
higher in scholarship, and there were fewer of them who 
failed or had conditions charged against them. 
In 1914 Dr. Bush carried on tests on college students 490 
THINGS THAT HOLD US BACK 
who smoked. After smoking, the students showed a per 
cent decrease in mental efficiency. He learned that the loss in 
efficiency was in imagery, perception, and association. Ciga- 
rette smoking seemed to be the cause of the most serious loss. 
Some men claim that smoking clears the mind, enabling 
them to accomplish more mental work than they could 
otherwise; while others maintain that smoking soothes the 
mind, enabling them to put 
aside worries and nervous- 
ness. It should be noticed 
that these claims are exactly 
the same as are those made 
for alcohol. And the inter- 
pretation of the effects ob- 
served is the same. The 
physiological effect is nar- 
cotic as wTith alcohol. The “brake is taken off the brain,” 
an expression employed by physiologists, although the feel- 
ing of some persons is that certain faculties of the mind 
have been stimulated to unusual activity. Others note 
the “soothing” effect, which is the distinctly drug activity 
of the tobacco. Men who are being “soothed” are being 
narcotized by the slow poison. The judgment of a man 
who is being affected by poison as to the comfort of a “good 
smoke” is hardly to be accepted. If an opium smoker told 
us that in his dreams he beheld certain wonderful things, 
more beautiful than he could see without the opium, we 
would hardly maintain that for this reason opium should 
be more widely used. 
Rather than accept the judgment of the narcotic user, 
wre ought to inquire concerning the actual effects of tobacco 
on the body. Some of these effects are a disturbance of the 
blood pressure, a more rapid heart action, shortness of breath, 
palpitation of the heart, pain in the region of the heart, and 
hardening of the arteries. It has also been noticed that 
Fig. 238. Cigar, Cigarette and 
Pipe. DISEASE 
491 
users of tobacco do not recover from operations so readily 
as do others. Tobacco also lessens the power of the volun- 
tary muscles, because of the depressing effect on the central 
nervous system. 
One of the regular chemicals in the stockroom of the sea- 
side laboratory of biology is nicotine. A drop of it in a dish 
of sea water containing specimens of delicate sea animals will 
paralyze their nervous systems immediately, and render 
them quiet for study. Yet many biologists are addicted to 
the use of tobacco. It is as if they stopped noticing effects 
when it came to considering themselves. 
Perhaps few intelligent men would deny that the use of 
tobacco in excess is a dangerous habit. But the extent to 
which each user employs this artificial soothing agent is 
considered by himself not to be excessive. A material that 
must be guarded against to prevent excess should reasonably 
have some easily demonstrated benefit. But tobacco has 
absolutely none. 
It has been maintained by good authorities that the 
prevalence of diseases of the heart and the circulation is in- 
creasing in this country. It is known that our per capita 
consumption of tobacco is increasing rapidly. In Great 
Britain the use of tobacco is decreasing, as is also the prev- 
alence of diseases of the heart and the circulation. A close 
parallel between these two sets of facts is thus demonstrated. 
Disease. The theory of disease prevalent in savage 
races to-day is the same as was probably passed through by 
civilized man. It is that an evil spirit or demon enters the 
body, and there causes various ills. Medicine-men or wizards 
endeavored to induce the evil spirit to leave the body, either 
by sacrifices, or by conciliatory measures, or by forcing it 
out through the agency of powerful charms, by beating 
tom-toms, or by pummeling the body of the patient. 
As civilization developed, there came into use the Hippo- 492 
THINGS THAT HOLD US BACK 
cratic theory of disease, called after its founder Hippocrates, 
“the Father of Medicine.” This theory was thoroughly 
believed in throughout the Middle Ages. According to it 
the human body contains four huviors, blood, phlegm, yellow 
bile, and black bile. In health the belief was that these 
humors existed in proper proportions, and that in disease the 
porportions were improper. 
As has been explained in the account of Pasteur, the germ 
theory of disease was formulated by Pasteur in connection 
with his studies of fermentation. This theory is accepted 
now by scientific workers all over the world, and the practice 
of medicine for the first time has become scientific. 
Although the civilized nations have progressed far in the 
matter of combating disease, the desirable end of eliminating 
it does not seem so simple of accomplishment as it may have 
seemed to be about the beginning of the Twentieth Century. 
Then physicians and the health authorities were probably 
over-enthusiastic about the discovery of the cell origin of 
communicable diseases. It seemed not too much to expect 
that through organized sanitation in city and country and 
through the isolation of patients that the most important 
of the devastating diseases could be checked at once and 
finally exterminated. 
Those who are not trained in medicine are liable to think 
that instead of the number of diseases being decreased, there 
are more of them than ever before. But this is only an ap- 
parent result. The study of disease has resulted in differ- 
entiating complaints into clearly defined diseases where gen- 
eral and vaguely understood physical ills formerly were 
treated. Besides, the development of commerce by explora- 
tion and travel has brought to the knowledge of men every- 
where the characteristic diseases of other countries. And it 
has sometimes happened that the diseases themselves have 
been transported to other lands than the ones where they 
were indigenous. DISEASE 
493 
However, no disease has been exterminated, nor is any 
likely to be in generations. It is true several have been 
greatly reduced in frequency and in their devastating effects, 
and this reduction is no doubt permanent. Diseases that 
are noticeably less frequent than they were before the dis- 
covery of the causes of communicable diseases are small- 
pox, typhoid fever, malaria, and bubonic plague. Diseases 
that are still all too common are tuberculosis, diphtheria, 
measles (a more dangerous disease than many imagine), 
scarlet fever, pneumonia, cancer, syphilis. Medical re- 
searches have reduced the fatality of these diseases but 
scarcely at all the frequency of their occurrence. 
There are also a group of diseases known as the organic 
diseases which were never more frequent than they are to- 
day. Bacteria have nothing to do with their prevalence, 
except in ways sometimes more or less remote. These dis- 
eases affect the internal organs of the body, especially the 
nervous system, the circulatory system, the kidneys, the 
digestive system. As already noted in an earlier section of 
this chapter, the use of alcohol and tobacco have a direct 
bearing on the prevalence of these diseases. To a consider- 
able extent also the general indulgence in an excessive amount 
of food tends to increase liability to these diseases. 
Happily for humanity the solution of the problem of ex- 
terminating organic diseases lies largely in our own hands. 
That is to say, the will to stop the enormous waste of human 
energy going out because of organic disease is all that it is 
necessary' to bring the undertaking into operation. But for 
the problem of stopping communicable diseases we need to 
fight long and intelligently to make the slightest impression. 
In the first place, the fight against disease is one that in- 
volves the efficient cooperation not only of cities, but also 
of states and nations, for the bacteria of disease break down 
all political boundaries. It is to the everlasting honor of 
the medical profession that its scientific investigators 494 
THINGS THAT HOLD US HACK 
have never held their discoveries within national limits. 
Scientists, medical foundations, and governments have co- 
operated and must continue to work together to save the 
members of the race from wasteful disease or early death. 
The question may easily arise as to why the regulations 
of boards of health have not been able to keep down the com- 
municable diseases. These rules are strict, and in general 
they are fairly well obeyed. When a communicable disease 
appears in a family the precautions in general, especially in 
the cities, are so effective that new cases seldom appear in 
the same family. But they appear elsewhere. 
Health authorities are now convinced that the chief 
reason that it will be difficult for a long time to come to 
eradicate disease is on account of the prevalence of what are 
known as “carriers.” These may be persons who have had 
the disease and continue to transport in their bodies the 
bacteria of the disease, or they may be persons who contract 
the disease in such form as not to become ill from it, or they 
may be persons in whose bodies the bacteria reside for a 
long time without making any impression. Investigation 
has shown that the number of carriers is far greater than 
is generally known. The nature of the case makes it difficult 
or seemingly impossible to detect all. 
One of the most famous cases of carrier is that of a woman 
known as “Typhoid Mary.” This woman was a cook, and 
she followed the common custom of changing places fre- 
quently. She had typhoid fever about the year 1907. 
Wherever she cooked some one or more members of the fam- 
ily became ill in about two weeks with typhoid fever. An 
investigator becoming suspicious of her connection with 
the numerous outbreaks of the disease followed her wander- 
ings from New York to Maine and back to New Jersey, 
finally succeeding in locating her and securing material 
from her intestinal tract that proved the existence of typhoid 
bacteria still in her body. She was forcibly detained in a hos- DISEASE 
495 
pital for a long time, and was finally discharged while still 
a carrier. Although this woman was probably not cleanly 
in her habits, the danger of permitting even cleanly persons 
who are carriers to prepare food, or in restaurants to wait 
upon their well customers is very great. It is often occasion 
for wonder that physicians and nurses so constantly in touch 
with disease seldom are known to carry disease to others, 
while persons in less exposed positions, like Typhoid Mary, 
may exist as menaces to the health of a community. Sani- 
tation or cleanliness is at the bottom of the difference. The 
physician or nurse is trained to be carefid, to wash the hands, 
to change the clothing, and to keep themselves in good health 
as a matter of professional preparedness. Probably Typhoid 
Mary seldom washed her hands. If our education created 
the instinctive habit of cleanliness in the race, the ravages 
of disease would doubtless be far less extensive than they 
are. 
Another place for general education on the score of health 
is the extension into all ranks of society of the truth about 
the causes of disease and the scientific methods of treatment. 
The causes of communicable diseases are undoubtedly micro- 
organisms of plant or animal origin, and yet there are great 
numbers of persons who profess to believe that “germs” 
do not exist except in the minds of the doctors. The un- 
fortunate fact is that the human mind has not developed 
to the extent of recognizing truth naturally. A bundle of 
prejudices clutter up the pathways of the brain. Long ed- 
ucation and the development of a racial habit of “thinking 
straight” are the main dependence of those who hope for 
success along this line. 
The recognition of the causes of disease entails a scientific 
search for the remedy, no matter what its nature. The main 
object in the scientific treatment of disease, let us realize, 
is the cure and prevention of disease in human beings. Many 
sentimental persons balk at this point, especially when they 496 
THINGS THAT HOLD US BACK 
see that the discovery of the cure of disease may lead to the 
destruction of life among some types of lower animals. They 
are unwilling to trust the scientific method, which is economi- 
cal of life by virtue of its very motive. Instead, many of 
these well-intentioned persons work to pass laws that hinder 
the saving of human life by assisting in the movement to 
stop experimentation with the lower animals. 
Now and then we hear them say that the inoculation of 
soldiers with typhoid vaccine even results in the death of 
large numbers of soldiers, in spite of what should be common 
knowledge that typhoid in soldiers’ camps nowadays is ex- 
tremely rare, while before vaccination for typhoid was dis- 
covered great numbers of soldiers in camps died of the 
disease. In spite of the fact also that smallpox has been 
well-nigh eliminated through the system of organized vacci- 
nation, many persons oppose vaccination, and strive to dis- 
credit a scientific discovery so obviously beneficial to man- 
kind. 
Smallpox vaccine, diphtheria serum, and the attenuated 
virus of hydrophobia respectively involve pain to cattle, 
to horses, and to rabbits. Shall we on that account decide 
to give up the cure of these diseases in human beings? This 
should be the test of the worth of the logical position held 
by those who call themselves “ anti-vivisectionists.” INDEX 
Abbatoir, 289 
Abdomen, 64 
Absorption, 388 
Acetanelid, 487 
Acetphenetidin, 487 
Acquired genius, 421 
Adams, John, 176 
Adaptation, 464 
Adrenal glands, 425 
Adrenalin, 426 
Adult, 327 
Afferent fibers, 413 
Agassiz, Jean Louis R., 466 
Age, neolithic, 160, 162, 181; new 
stone, 160; paleolithic, 181; pol- 
ished stone, 160; old stone, 157; 
rough stone, 157; 
Agriculture, Dept of, 245 
Ailanthus, 291 
Air-pore, 249, 251 
Albinism, 204 
Alcohol a narcotic, 482; com- 
parisons, 488 
Alcoholism, 206 
Aleurone layer, 301 
Algonkian, 147 
Alligator, 109, 148 
Alternation of generations, 237 
Amino-acids, 385 
Ammonia compounds, 226 
Amoeba, 7 
Amphibia, 100, 147 
Amylopsin, 385 
Animals, domesticated, 181; origin 
of, 147; prehistoric, 143 
Annelid, 147 
Annual rings, 271 
Anopheles, 10, 41 
Ant, 44; agricultural, 47; colony, 45 
Antelope, prong-horned, 126 
Anther, 211 
Antheridium, 236, 240 
Antherozoid, 236, 240 
Anthrax, 324 
Arthropoda, 70 
Anthropologist, 164 
Antipyrin, 487 
Antiseptics, 460 
Antitoxin, 450 
Anti-vivisectionists, 497 
Ant-lion, 60 
Aorta, 329, 392 
Ape, 155; anthropoid, 154 
Appendicitis, 386 
Apple, 277, 278, 339, 342; Baldwin, 
279; “seedling,” 278; wealthy, 282 
Archean, 147 
Archegonium, 236, 240 
Aristotle, 1, 450 
Ashes, 286 
Asparagus, 347 
Aspen,273 
Atlantosaurus, 147 
Athletics, 445 
Atom, 333, 336 
Auricle, 391 
Australian, 164 
Aves, 121 
Axis cylinder, 414 
Axon, 414 
Babe Ruth, 418 
Bacteria, 222 
Bacteria, nitrifying, 226; nitrogen- 
fixing, 227, 256; soil, 213 
Bacterium, 8,222 
Bailey, Prof. L. H., 284 
Barberry, 231 
Bark, inner, 259; outer, 259 
Barley, 297 
Barnacle, 147 
Bast fibers, 259 
Bat, 130, 147 
Bee bread, 43 
Bee, bumble, 212 
Beans, 256, 305, 343, 346, 347: 
bush, Lima, pole, 257 
Bear, 147 
Bear-dog, 195 
Beet, 342 
Begonia leaf propagating, 281 
Benzoate of soda, 365 
497 498 
INDEX 
Beriberi, 300, 348, 349 
Bichat, Marie Francois X., 456 
Bidens, 291 
Bile duct, 380, 385 
Biology, 16 
Biological interdependence, 287 
Bison, 147, 202 
Blacksnake, 102 
Bladder, 403 
Blood, composition of, 393 
Blood-poisoning, 223 
Blood vessels, 330, 405 
Blubber, 125 
Bluebird, 120 
Boar, wild, 193 
Bones, 439 
Boric acid, 365 
Boulder, 145 
Brachiopod, 147 
Bract, 252 
Brain of alligator, 410; of frog, 410 
of lizard, 410; of pigeon, 410 
of salmon, 410; organization, 420 
power, 419 
Bran, 301 
Branchiosaurus, 147 
Bread, 343, 346; Boston brown, 254; 
mold, 229 
Breathing pores, 259 
Bright’s disease, 482 
Broccoli, 304 
Brontosaurus, 147, 148 
Bronchial tubes, 401 
Brood-pouches, 74 
Brussels sprouts, 304 
Bryozoa, 147 
Bubonic plague, 460 
Buckwheat, 297 
Bulb, 280 
Bundle, fibrovascular, 247, 258 
Burbank, Luther, 283 
Burdock, 291 
Burroughs, John, 477 
Butter, 310, 311, 344, 348 
Butterfly, 147; black swallow-tail, 
55 
Cabbage, 304; descendants of wild, 
304; wild. 304 
Cactus, spineless, 284 
Caffein, 368, 487 
Calcium salts, 347 
California Fruit Growers Exchange, 
308 
Calyx, 261 
Camel, 147 
Cambium, 258, 260 
Cambrian, 147 
Cane, 309, 310 
Canines, 373 
Cannabis indica, 487 
Cannon-bone, 184 
Cannon, Prof. W. B., 383 
Capillaries, 396, 403 
Carapace, 106 
Caraway seeds, 301 
Carboniferous, 147 
Carbon, 332 
Carbon-dioxide, 82, 209, 250, 330 
Carbohydrate, 209, 215, 217, 250, 
331, 332 
Carbolic acid, 460 
Carnac, 162 
Carrot, 342, 343, 347 
Cartilage, 439 
Cassowary, 121 
Cat, 198; Egyptian, 198; family, 147 
Caterpillar, 48, 58 
Caterpillars, silkworm, 326 
Cattle, 189 
Cauliflower, 304 
Cave bear, 159 
Cecropia, 58 
Cell, generative, 264; sap, 217; 
vegetative, 264 
Cellulose, 366 
Cement, 374 
Cenozoic, 147 
Centipede, 69 
Cephalopod, 147 
Cerebellum, 412 
Cerebral lobes, 411 
Cerebrum, 411 
Chamois, 161 
Character, dominant, 189, 204; 
recessive, 189, 204, 472 
Characters, acquired, 461; domi- 
nant, 472; unit, 285 
Chameleon, 108 
Chapman, Frank M., 116 
Charcoal, 274 
Cheese, 344, 346, 348; Rocquefort, 
230 
Chicken, 199 INDEX 
499 
Chicken cholera, 460 
Chicken-farming, 201 
Chipmunk, 128, 243 
Chittenden, Prof. R. H., 352 
Chloral hydrate, 487 
Chlorophyll, 209, 250 
Chocolate, 369 
Chromosomes, 470 
Cilia, 6, 73 
Circulatory system, 329, 390, 393 
Citrus fruits, 307, 308 
Clam, soft-shell, 74 
Click-beetle, 53 
Clothing resources, 317 
Clover tubercles, 226 
Cluster cups, 231 
Cob, 252 
Cocain, 487 
Cochineal, 62 
Cockroach, 147 
Cocoa, 369 
Cocoanut oil, 310 
Cocoon, 44, 45, 325, 327 
Codein, 487 
Codfish, 85 
Coelentera, 22 
Coffee, 368; cereal, 358 
Cold storage, 364 
Composition of foods, 333 
Conceptacle, 219 
Conjugation, 216 
Conjugation-tube, 218 
Conklin, Prof. Edwin G., 203 
Constipation, 387 
Consumption “cures,” 490 
Contractile vacuole, 6 
Control of living, 409 
Cooking, 365 
Coral polyp, 21, 147 
Cornx ear, 244 
Corn, Indian, 243, 297, 339, 342, 343 
Corn meal, 254 
Com oil, 255, 312 
Corolla, 261 
Corpuscles, red blood, 10, 395; 
white and red, 394 
Cortical area of brain, 416 
Cotton, 317; bale, 321; field, 319; 
gin, 319; gin, modern, 320; 
plant, 318; seed, 320; seed oil, 310 
Cotyledon, 259, 301 
Cow, milch, 314 
Crab, 147 
Cranial nerves, 413 
Creatin, 34(i 
Creatinin, 400 
Creosote, 273 
Cretaceous, 147 
Cretin, 173 
Criminality, 206 
Crinoid, 147 
Crocodile, 148 
Cromlech, 162 
Crow, 116 
Culex, 41 
Curd, 311 
Cuttlefish, 79 
Cuvier, Georges, 4.55 
Cytoplasm, 7, 214 
Dairy farming, 311, 314 
Darwin, Charles, 152, 182, 212, 
427, 437,463 
Davenport, Charles B., 203 
Death rates, 363 
Deer, 147; Irish, 161 
Dendrons, 414 
Dental floss, 375 
“Dental insurance,” 377 
Dentine, 374 
Dermis, 404 
Devonian, 147 
DeVries, Hugo, 282, 472, 475 
Diabetes, 403 
Diaphragm, 372 
Dickerson, Mary C., 95 
Dicotyledon, 260 
Diet, vegetarian, 345 
Diffusion, 249 
Digestive system, 371, 372 
Dionin, 487 
Diphtheria, 148, 223, 362, 460 
Disease, 492 
Disease “carriers,” 495 
Diseases, “deficiency,” 349 
Dispersal of seeds, 290 
Ditmars, R. L., 108 
Dog, 147, 181,195; mad, 458 
Dolmen, 162 
Dragon-fly, 61, 147 
Dust, volcanic, 140 
Ear, inner, 435 
Ears, care of, 436 
Earthworm, 27 500 
INDEX 
Echinoderma, 26 
Edwards, Jonathan, 176, 204 
Eel, 83 
Effect of altitude on plants, 282 
Egg, 64, 315, 327, 339, 344, 347; 
“candling,” 315, 316; case, 220; 
cell, 220, 237; nucleus, 221, 253; 
preservation, 315 
Eighteenth Amendment, 481 
Elephant, imperial, 147 
Embryo, 15, 29, 237, 254, 301 
Endosperm, 253, 254, 301 
Enamel, 374 
End-products in digestion, 400 
Energy, 335, 336 
Environment, 208 
Enzymes, 224, 228, 250, 343, 382 
Eocene, 147 
Eohippus, 150, 151 
Epidermis, 260, 404, 405 
Epilepsy, 206 
Equus, 151 
Era, 146 
Erepsin, 385 
Erysipelas, 436 
Esquimaux, 164 
Ethnologist, 170 
Ethnology, 168 
Euthenics, 179 
Eugenics, 174, 476 
Eugenics laboratory, 176 
Eugenist, 476 
Eurypterida, 147 
Eustachian tube, 436 
Evolution, 152, 461, 463 
Excretion, 399 
Eye infections, 438 
Eyes, 435 
Eyes, care of, 438 
Eyestrain, 437 
False feet, 8 
Farm, 286; improved, 288 
Farming, scientific, 245 
Far-sightedness, 437 
Fat globules, 405 
Fats, 254, 310, 331, 344 
Fatty acids, 385 
Feeble-mindedness, 206 
Fermentation, 228 
Fern. 235; Boston, 238; cinnamon, 
238 
Fertilization, 211, 263, 264 
Fertilization of soil, 288 
Fertilizer, 289 
Fetlock, 184 
Fibrinogen, 395 
Fibrovascular bundles, 259 
Fire-fly, 54 
Fish, 158 
Fish, armored, 147; bony, 147; 
lung, 147 
Fission, 214 
Fleece, 324 
Fletcher, Horace, 351 
Flour, “bolted,” 302 
Flour, Graham, 302 
Flower, 211, 261; pistillate, 252; 
staminate, 252 
Flowers, insect-pollinated, 212 
Flowers, wind-pollinated, 211 
Food resources, 297 
Foods, natural, 338, 339 
Foramenifera, 9, 147 
Forest conservation, 269 
Forest fire, 275 
Forest protection, 275 
Forests, 265 
Formaldehyde, 273, 365 
Fossil, 141 
Fox-dog, 195 
Frog, leopard, 92; development of, 
94 
Frond, 238 
Fructose, 310, 341 
Fruit sugar, 310 
Fruits, 307 
Fungus, 209, 229 
Fungus, bracket, 234, 274 
Funk, Casimir, 348 
Fur, 317 
Furfural, 490 
Gall-fly, 49 
Galton, Sir Francis, 174, 475 
Gastric fluid, 382 
Gastropod, 147 
Gall bladder, 380 
Gamete, male, 264 
Gelatine, 366 
Generation, asexual, 241; non-sex- 
ual, 237; sexual, 237 
Geranium, wild, 291 
Germ, 252 INDEX 
501 
Germ-plasm, 470 
Germ-pore, 264 
Giant jellyfish, 19 
Gill, 73, 82 
Gill-covers, 82 
Gizzard, 121 
Glacial epoch, 154, 467 
Glacier, 145 
Gladstone, William, 429 
Glands, digestive, 381 
Glucose, 228, 249, 255, 310, 332, 341, 
343 
Glycerin, 385, 399 
Glycerol, 399 
Glycogen, 398 
Glyptodon, 147 
Gorilla, 155 
Grafting, 279, 280 
Grain products, 297 
Grand Canyon, 141 
Grape fruit, 308 
Grasshopper, 62, 63 
Gray, Prof. Asa, 473 
Grouse, ruffed, 112, 203 
Growing, 334 
Guinea pig, 483 
Gulick, Dr. Luther, 407 
Gullet, 7, 379 
Habit, 417 
Haddon, A. D., 163 
Hsemaglobin, 347, 358, 394 
Hair follicle, 405 
Hall, Prof. W. S., 356 
Harvey, William, 452 
Hawk, chicken, 114; Cooper’s, 114; 
red-tailed, 114 
Head, 64 brachycephalic, 164; doli- 
chocephalic, 164 
Heart, 329, 392 
Hemp, 286 
Heredity, 153, 471 
Heroin, 487 
Hesperornis, 147 
Hickory nuts, 344 
Hippocrates, 493 
Histologist, 453 
“Hoe” cake, 254 
Hold-fasts, 219 
Holmes, Dr. Oliver Wendell, 79 
Hominy, 254, 339, 343, 346 
Homo sapiens, 163 
Honey, 339, 342 
Honey-bee, 41 
Honey-bee drones, 42; neuters, 42; 
queens, 41; workers, 42; swarm- 
ing, 42 
Honeycomb, 43 
Honey-dew, 47 
Hookworm, 33 
Hornaday, Dr. William T., 112 
Hornet, 49 
Horse, 147, 150, 152, 158, 182; 
dawn, 150; evolution of the, 151; 
wild, 152,182, 186 
House-fly, 36 
Human brain, the, 409 
Human machine, the, 335 
Human will, the, 417 
Humors, 493 
Husk, 252 
Huxley, Thomas Henry, 155, 159, 
468 
Hybridization, 284 
Hydra, 18 
Hydrogen, 332 
Hydroid, 147 
Hydroids, 16 
Hydrophobia, 460, 497 
Hyena, 159 
Hyena-dog, 195 
Hyracotherium, 151 
Hysteria, 206 
Ibex, 158 
Ice Age, 154 
Ichthyornis, 147 
Ichthyosaurus, 147 
Ideals, 431 
Incisors, 373 
Indian, American, 164 
Indian corn, 277 
Industry, pork-packing, 312 
Inheritance, 461, 463, 472; social 
control of, 178 
Ink, India, 79 
Insanity, 206 
Insecta, 64 
Insects, 36 
Instinct, 196 
Intestine, 329, 380; large, 372, 387; 
section of, 388; small, 372, 380, 399 
Invertebrate, 147 
Iron, 332, 334 502 
INDEX 
Jam, 342 
James, Prof. William, 421, 425, 
427, 428 
Jennings, Herbert Spencer, 203 
Johnny cake, 254 
Jukes family, 177 
June-bug, 51 
Jungle fowl, 200 
Jupille, 459 
Jurassic, 147 
Kale, 304 
Kallikak family, 177 
Kidneys, 329, 330, 402, 403 
Kidney tubule, 403 
King Alcohol, 480 
Koch, Dr. Robert, 459 
Kohlrabi, 304 
Kropotkin, Prince, 165, 168 
Lactase, 385 
Lacteals, 399 
Lactometer test, 315 
Lady-bug, 52, 62 
Lake dwellings, 161 
Lamarck, Jean Baptiste, 461 
Larva, 57, 327 
Larvae, 39 
Larynx, 401 
Lava, 141 
Law, Mendel’s, 190, 206 
Lazear, Dr. Jesse W., 11 
Leaf, 260 
Legumes, 348 
Lemons, 308 
Lenticels, 259 
Lettuce, 347 
Life on the farm, 293, 294, 295 
Ligaments, 444 
Lime salts, 348 
Lincoln, Abraham, 430 
Linen, 286, 317, 321 
Linnaeus, Carl, 454 
Linseed oil, 322 
Lion, 147, 161 
Lipase, 385, 399 
Lister, Sir Joseph, 460 
Liver, 329, 330, 372, 381, 392, 399 
Lizard, 108 
Lobster, 65 
Lockjaw, 460 
Locust, Carolina, 63; clouded, 63; 
red-legged, 63; Rocky Mountain, 
63 
Lungs, 266, 329, 372, 392, 401, 402 
Lye, 286 
Lymph glands, 397; spaces, 397; 
system, 395, 396; vessels, 389, 
397, 399 
Macronucleus, 6 
Magnesium, 334 
Magnesium salts, 347 
Malaria, 10 
Malarial parasite, 10 
Malpighi, Marcello, 453 
Malt, 297 
Maltase, 385 
Maltose, 332 
Mammal, 146 
Mammalia, 136 
Mammals, Age of, 151 
Mammoth, 158 
Man, 147; Age of, 151; birthplace of, 
156; cave, 156, 160, 181; Cro- 
magnon, 160; feeble-minded, 173; 
Java, 159; Mendelian Inheritance, 
in, 203, 205; Neanderthal, 158, 165 
Man’s origin, 154 
Man’s relatives, 155 
Mantle fold, 73 
Maple, 291 
Maple sap, collecting, 341 
Marsupial, 149 
Mastodon, 147 
Mastodonsaurus, 147 
Mastoiditis, 436 
May-beetle, 52 
May-fly, 147 
Measles, 436 
Meat, 339, 344, 346, 347 
Meat inspection, federal, 313 
Meats, 312 
Medulla, 412 
Medullary plates, 259 
Medullary rays, 259 
Medusae, 16 
Megatherium, 147 
Menace, the drug, 487 
Mendel, Gregor, 177,198, 285, 471 
Mendel’s Law, 177 
Men, Races of, 163 
Menhir, 162 
Menu, scientific, 359 INDEX 
503 
Meryehippus, 150 
Mesentery, 392 
Mesohippus, 151 
Mesozoic, 147 
Meta-protein, 385 
Metschnikoff, Prof. Elie, 395 
Micronucleus, 6 
Middle ear, 435 
“Middlings,” 301 
Milk, 313, 339, 342, 344, 346; in- 
fected, 362 inspection, 362; sour- 
ing, 361; sugar, 332 
Milker, mechanical, 314 
Mind, independent, 430 
Miocene, 147 
M ivart. Prof. Saint George, 198 
Molars, 373 
Molecule, 249, 250, 333, 336 
Mollusca, 80 
Molt, 39 
Monocotyledon, 259 
Monument, Druid, 162 
Morphine sulphate, 488 
Mosasaurus, 147 
Mosquito, 10, 38 
Mosquito control, 40 
Moss, 235 
Moth, 58, 325 
Moth eggs, 325 
Motor-fibers, 416 
Motor and sensory connections, 416 
Mud puppy, 100 
Mule, 187' 
Muller, Johannes, 456 
Muscles, 439, 443 
Mushroom, 232; field, 233; “gills,” 
233; “inky-cap,” 233; “shaggy- 
mane,” 233 
Muskrat, 72 
Mussel, fresh-water, 72 
Mutation, 145, 153, 165, 189, 475 
Mutual aid, 165, 168 
Natural selection, 463 
Nature, 2 
Nautilus, chambered, 79 
Near-sightedness, 437 
Neck-canal, 240 
Nectar, 210, 212 
Necturus, 100 
Negro, 164 
Neo-Darwinians, 471 
Nerve-cells, 414 
Nerve-fiber, 413 
Nerve units, 414 
Nervous system, 409 
Nervous system, autonomic, 423, 
424, 426,443 
Nervous system, central, 443 
Neuron, 414, 420 
Newt, 98 
Nicotine, 490 
Nitrate, 213 
Nitrogen, 213, 332 
Nodes of Ranvier, 414 
Noguchi, 12 
Nucleus, 7, 13, 214; of nerve cell, 
414 
Nucleolus, 7 
Nuthatch, 119 
Nuthatch, white-breasted, 119 
Nutrient, 331 
Nutrients, inorganic, 346 
Nuts, 307 
Oatmeal, 299, 339, 343, 346, 347 
Oats, 299, 300 
Observer’s tower, 274 
Octopus, 79 
(Esophagus, 380 
Oil glands, 406 
Oils, 310; vegetable, 344 
Oleomargarine, 310, 311 
Olfactory nerves, 411, 413 
Oligoeene, 147 
Olive oil, 310, 311 
Olive trees, 312 
Onion, 342 
Oosperm, 241 
Optic lobes, 412 
Optic nerves, 413 
Opossum, 123, 147 
Orange, 339, 342 
Orchard fruits, 307 
Ordovician, 147 
Organism, 3 
Organs, secreting, 371 
Orris root and chalk, 375 
Osmosis, 248, 389 
Osteoclasts, 439 
Ostrich, 121 
Ovary, 64, 252, 262 
Ovaries, 29 
Overweight, 447 504 
INDEX 
Ovule, 253, 262 
Ox, 188; long-horned, 188; musk, 
161; wild, 158 
Oxygen, 250, 330, 332, 347 
Oxidation, 83, 251, 336, 347, 399 
Oyster, 75, 147 
Paleozoic, 147 
Paleolithic Age, 157 
Paleontologist, 154 
Paleontology, 154 
Palisade cells, 260 
Pancreas, 371, 372, 381 
Pancreatic duct, 380 
Papillae, 378 
Paramcecium, 6, 203 
Parasite, 209, 222 
Pariasaurus, 147 
Parsnips, 343 
Partridge, 112 
Pasteur, Louis, 458 
Patent flour, 302 
Peanut butter, 344, 346, 347 
Peanut oil, 311 
Pearls forming, 73 
Peas, 305, 343, 346 
Pellagra, 349 
Pepsin, 382 
Peptones, 385 
Peripatus, 147 
Permian, 147 
Perspiration, 405 
Pestle, 161 
Petal, 261 
Phagocyte, 394 
Pharynx, 379, 401 
Phenacetin, 487 
Phenacodus, 147 
Phosphorus, 332, 334 
Photosynthesis, 216, 217, 250, 261 
“ Phrenology, ” 420 
Physiologist, 410 
Pig, 193 
Pill-bug, 147 
Pine, mountain, 282 
Pistil, 211, 261 
Pith, 247, 258 
p,fli /ipllc 2/)() 
Plant, breeding, 277; female, 264 
lice, 47 
Plants, green, 209; non-green, 222 
Plasma, 395 
Plastron, 106 
Pleistocene, 147, 154 
Plesiosaurus, 147 
Pleurococcus, 214 
Pliocene, 147 
Plumcot, 283 
Plumule, 253, 258, 301 
Pneumonia, 223 
Poison gland, 105 
Polistes, 49 
Pollen, 211, 252 
Pollination, 211, 263; cross, 264; 
self, 213, 263 
Polliwog, 98 
Pompeii, 140 
Portal vein, 398 
Posture, correct, 442 
Potassium, 334 
Potassium salts, 348 
Potato, 277, 278, 305, 343; “eye,” 
278; sweet, 305, 306, 342, 343 
Precooling fruit, 309 
Premolars, 373 
Preservative, chemical, 365 
Prohibition, 481 
Propagation from parts, 279 
Protective resemblance, 464 
Protein, 254, 331, 345; protecting 
foods, 337; sparing foods, 337 
Proteins, complete or perfect, 400 
Proteose, 385 
Prothallus, 240 
Protohippus, 151 
Protonema, 237, 239 
Protoplasm, 7, 334 
Protorohippus, 151 
Protozoa, 13 
Psychologist, 410 
Pteranodon, 147 
Pterodactyl us, 147 
Ptomaines, 365 
Ptyalin, 382 
Pulse, 390 
Pupa, 38, 325, 327 
Pure Food Law, 341 
Pure line, 190 
Pylorus, 380 
Pyorrhea, 376 
Pyrenoids, 217 
Pyridin, 490 
Quadrupeds, 31 INDEX 
505 
Rabbit, 147 
Race, yellow, 164 
Racer, blue, 102 
Radial canals, 18 
Radicle, 253, 258, 301 
Radiolaria, 147 
Rattlesnake, 104 
Reaping oats, 302 
Rectum, 372 
Redwood, 271 
Reflex action, 415 
Reindeer, 157, 158 
Renal corpuscle, 403, 404 
Rennin, 382 
Repairing, 334 
Reproduction, 7, 215; sexual, 217, 
230 
Reptile, 111 
Reptiles, Age of, 151 
Reptilia, 111 
Resemblance, aggressive, 136; pro- 
tective, 136 
Respiration, 251 
Retting of linen, 322 
Rheumatism, 359 
Rhinoceros, 147; wooley, 159 
Rhizoid, 240 
Rice, 298, 299 
Rice, brown, 300; polished, 349 
Rice polishing, 300 
Rickets, 349, 440 
Rigg’s disease, 376 
Rind, 247 
Robin, 120 
Rock weed, 218 
Root-hairs, 246, 258 
Root, primary, 253 
Root-stock, 280 
Root-tubercles, 256 
Rosin, 273 
Royal jelly, 44 
Rumen, 192 
Ruminant, 192 
Rye flour, 301 
Saccharin, 487 
Saccharose, 341 
Sago, 343 
St. Vitus’ Dance, 206 
Salamander, 98 
Salicylic acid, 365 
Salivary glands, 371, 381 
Salmon, 88 
Salmon, chinook, 89 
Salts, inorganic, 331, 334 
Samp, 254 
Sandworm, 30 
Saprophyte, 210, 222 
Scale-bug, 61 
Scale-insect, 53 
Schleiden, Matthias Jakob, 457 
Schultze, Max, 457 
Schwann, 457 
Scorpion, 147 
Scraper, 161 
Scurvy, 349 
Sea-fan, 23 
Seal, fur, 131 
Sea-pen, 23 
Sea urchin, 25, 147 
Sebaceous glands, 406 
Sense organs, 434, 435 
Sensory-fibers, 416 
Sepal, 261 
Seton, Ernest Thompson, 112 
Shagreen, 85 
Shaler, Prof. N. S., 195 
Shark, 84,147; basking, 84;white, 84 
Shellac, 62 
Sheep, 192 
Sheep-shearing, 323 
Shoes, 441 
Sieve tubes, 259 
Silk, 317, 326; weighted, 327 
Silkworm, 57 
Silkworm caterpillar, 325 
Silkworm, Life history of, 325 
Silurian, 147 
Silver nitrate, 438 
Siphon, 72 
Skeleton, 439; care of, 440 
Skin, section, 405 
Slime, green, 214 
Slipper animalcule, 6 
Slug, 78 
Smallpox, 497 
Snail, land, 77; sea, 78 
Snellen card, 438 
Soda fountain, 369 
Sodium, 334; chloride, 347; salts, 348 
Soil-water, 249 
Somites, 35, 64 
Sorus, 238 
Species, The Origin of, 152 506 
INDEX 
Spermaries, 29 
Spermary, 64 
Spermatozoa, 15, 64 
Sperm-cell, 220, 236 
Sperm-nucleus, 253 
Sphagnum, 235 
Sphenedon, 147 
Spider, 67, 147 
Spider, garden, 68 
Spinach, 347 
Spinal column, 440 
Spinal cord, 412 
Spiracles, 71 
Spirogyra, 215 
Splenic fever, 460 
“Splint” bone, 184 
Sponge, 14, 147 
Sporangium, 238 
Spore, 224, 233 
Spores, spring, 231; summer, 231 
winter, 231: of yeast, 227 
Sporidium, 232 
Sport, 282 
Squid, 79, 86 
Squirrel, 147 
Stamen, 211, 261 
Starch, 250, 343 
Starch, corn, 255 
Starfish, 23, 147 
Steapsin, 385 
Stegomya, 11 
Stegosaurus, 147 
Sterilization, 460 
Stigma, 211, 253, 262 
Stiles, Dr. C. W., 34 
Stockard, Prof. C. R., 484 
Stoma, 231 
Stomata, 251 
Stomach, 372, 379, 380 
Stonehenge, 162 
Strabismus, 437 
Strata, 141 
Strawberry plant, 307 
Striated muscle cells, 443 
Style, 252, 262 
Sucrase, 385 
Sucrose, 309 
Sugar, 309 
Sugar beet, 309 
Sugar, cane, 309 
Sugar, maple, 341 
Sugars, 341 
Sulphur, 332 
Swarming, 44 
Sweat glands, 405 
Sweetbread, stomach, 381 
“Sweetening” of soil, 288 
Swimmeret, 66 
Syntonin, 385 
Syrup, 342 
Tadpole, 95 
Tannic acid, 368 
Tanning agency, 286 
Tapeworm, 31 
Tapioca, 343 
Tapir, 147 
Tar, 273 
Tarpan, 182 
Tartar, 374, 376 
Tassel, 252 
Tea, 368 
Teeth, brushing, 375; care of, 375; 
milk, 373; mistreated, 373; per- 
manent, 373; “wisdom,” 372 
Tendons, 444 
Tentacles, 73 
Tertiary, 151 
Textiles, 326 
Theine, 368 
Theobromin, 369 
Thomson, J. Arthur, 212 
Thomson, Dr. William Hanna, 
421, 429 
Thoracic duct, 399 
Thorax, 54 
Threshing wheat, 303 
Thrush, hermit, 120 
Thrush, wood, 120 
Thunder lizard, 148 
Thymus gland, 372 
Thyroid gland, 312 
Tiger, 147 
Tiger, saber-tooth, 144 
Tissue, connective, 366 
Titanothere, 147 
Toad, 95 
Tobacco, 489 
Tobacco a narcotic, 491 
Tongue, 378 
Tooth, vertical section, 374 
Tortoise, box, 106 
Trachea, 71 
Transpiration, 251 INDEX 
507 
Transforming plant food to animal 
food,289 
Trap, salmon, 90 
Trawl, 86 
Triassic, 147 
Triceratops, 147 
Trilobite, 147, 148 
True skin, 405 
Trypsin, 384 
Tube-feet, 23 
Tuberculosis, 223 
Turnip, 343 
Turpentine, 273 
Turtle, 147 
Turtle, box, 106 
Typhoid fever, 38, 223, 362, 364 
“Typhoid Mary,” 495 
Typhoid vaccine, 497 
Uintatherium, 147 
Underweight, 447 
Urea, 400 
Ureter, 403 
Uric acid, 359, 400 
Vaccination, 497 
Vacuole, 227 
Variation, 463 
Variation in plants, 280 
Vena cava, 329; inferior, 393; 
superior, 393 
Vegetables, 303 
Ventilation, 407 
Ventricle, 391 
Vermes, 35 
Vermiform appendix, 372, 381 
Vesalius, 451 
Vespa, 49 
Vesuvius, 140 
Villi of intestine, 388 
Virchow, Rudolph, 457 
Virus, attenuated, 459 
Vitamin, 311, 314, 331 
Vitamin “A,” 349 
Vitamin “15,” 349 
Vitamin “C,” 349 
Vitamins, 348 
Vodka, 480 
Voluntary muscles, 443 
Wallace, Alfred Russell, 466 
Walrus, 147 
Warm bath values, 406 
Wasp, 48 
Wasp nest, 48 
Waste elimination, 401 
Waste from lungs, 402 
Water, 331, 334 
Weasel, 134 
Weeds, 290 
Weismann, August, 470 
Whale, 147 
Whalebone, 126 
Whale, right, 125 
Wheat, 300; grain, 301; in mill, 292; 
rust, 230 
Whip-poor-will, 115 
Whitney, Eli, 319 
Will, 421 
Windpipe, 401 
Wood-alcohol, 273 
Wood ducts, 259 
Wood fibers, 259 
Wood lots, 272 
Wolf, 195 
Wool, 323 
Work, 444 
Wren, house, 118 
Wrigglers, 11, 39 
Yeast, 227 
Yeast, wild, 228 
Yellow fever parasite, 11 
Yellow jacket, 49 
Zygote, 230, 231, 237, 253, 264