HAECKELS 
-::(|fnfsis of iDan. 
-BV Lester F. Ward, A. M. 
EDWARD STERN & CO., 
125 and 127 North Seventh Street.-^ HAECKEL’S GENESIS OF lAN 
= OR = 
Pistroj of tljc tlfl’i'lopnunt of t|c 
|)uman llittt. 
BEING A 
REVIEW OF HIS “ANTHROPOGENIE,” AND EMBRACING A 
SUMMARY EXPOSITION OF HIS VIEWS AND OF 
THOSE OF THE ADVANCED GERMAN 
SCHOOL OF SCIENCE. 
BY 
LESTER F. WARD, A.M. 
EDWARD STERN & CO. 
Philadelphia: 
r2j c° 127 North Seventh St. Entered according to Act of Congress, in the year 1879, by 
EDWARD STERN & CO., 
In the Office of the Librarian of Congress, at Washington, D. C. 
PRESS OF EDWARD STERN & CO., 
125 & 127 NORTH SEVENTH STREET, PHILA. PREFACE. 
'T'HE three papers constituting this little brochure were originally 
J. contributed to the Penn Monthly, and appeared in the April, 
May, and July numbers of that magazine for 1877. 
As the work which it was their more especial object to review 
has not yet been placed before the non-German reading public, no 
apology is offered for their reproduction in separate form. 
In view, however, of the popular interest which the views 
of Prof. Haeckel have since called forth, and which seems to be 
still increasing, it was thought an opportune moment for laying 
before the general public this condensed exposition of the thought 
and labors of the great naturalist and philosopher. 
It may further interest the reader to learn that Prof. Haeckel 
has acknowledged, in a private communication to the author, the 
substantial correctness with which these papers represent his 
position. 
L. F. W. 
Washington, March, 18yp. HAECKEL’S GENESIS OF MAN, OR HISTORY OF THE 
DEVELOPMENT OF THE HUMAN RACE.1 
I. 
GENERAL HISTORY OF THE DOCTRINE OF DESCENT. 
IT is no derogation from the epoch-making labors of Charles 
Darwin to admit that the arguments he has presented in sup- 
port of his celebrated theory constitute, as it were, but the half of 
the vast array which the present state of biological science is capable 
of marshalling in its defence. 
The sources from which the evidences of descent and natural 
selection must be derived, may be divided into two general classes: 
First, Paleontology, Comparative Anatomy and Osteology, and 
Geographical Distribution (Chorology), i. e., a comparison of the 
adult forms of animals both living and fossil (.Phytogeny); and 
Second, the study of embryonic changes and post-natal metamor- 
phoses, or a comparison of undeveloped animal forms (Ontogeny). 
Of these two classes it may be said that the first have been fur- 
nished by Darwin, the second by Haeckel. Not that Darwin, 
either in his Origin of Species or in his Descent of Man, has wholly 
ignored the bearing of embryological considerations upon his 
theory. In the former work he has devoted seventeen pages of 
one of his concluding chapters to “ Development and Embry- 
ology ; ” the greater part of which, however, is occupied in pointing 
out the importance of the various kinds of metamorphosis, chiefly 
as it is observed in insects, amphibians, etc., after birth ; only inci- 
dentally referring to those more obscure metamorphoses which 
take place within the egg or the uterus. 
He does allude, however, more directly to Von Baer’s law, but 
without designating it as such ; and contents himself with quoting 
the passage, cited also by Haeckel in the preface to the third edi- 
tion of his History of Creation (1870), in which the great Russian 
embryologist remarks upon the striking similarity of many em- 
1 Anthropogenic, oder Entwickelungsgeschichte des Menschen, von Ernst Haeckel, 
Professor an der Universitat Jena. Leipsic, 1874. 6 
GENESIS OF MAN. 
bryos, so much so that he was quite unable to say to what animals 
two specimens which he had preserved in alcohol but had neglected 
to label, really belonged. Still less attention has Darwin paid to 
this source of argument in his Descent of Man. A few lines quoted 
from Von Baer and from Huxley, on page 14 of Vol. I, a figure of 
the embryo of a human being and one of a dog, from Ecker, on 
page 15, with brief comments, disposes of this branch of his great 
argument. Almost as much had been said by the author of the 
Vestiges of Creation, in 1842.2 It is safe, therefore, to assume 
that at the time of the appearance of the Origin of Species (1859), 
Darwin had no conception of the real part that the arguments from 
embiyology were destined to play in establishing his doctrine 
of the development of organic forms. And although in subse- 
quent editions he was able to notice the Gcnerelle Morphologic, it is 
still improbable that even then he had any adequate idea of the 
powerful ally he was to have in Germany, as the Naturliche Scliopf- 
ungsgeschichte, and not less the work under review, have proved 
the professor of Jena to be. It is of the former of these works 
that Darwin says that if it had appeared before the Descent of 
Man had been written, he would probably never have completed 
the latter. 
Professor Haeckel is no mere disciple of Darwin, profound as is 
his admiration of him, and unreserved as is his expression of that 
admiration. His own countrymen have accused him of being 
“ more Darwinistic than Darwin himself,” but it is clear that a 
large part of this difference is in.kind rather than in degree, and 
that he has infused into the developmental philosophy a true 
Haeckelian element. It is true that he drew the logical conclusion 
from the premises furnished by the Origin of Species five years be- 
fore the announcement of its recognition by Darwin himself in his 
Descent of Man. This conclusion he boldly and forcibly enunci- 
ated in the introduction to his Genercllc Morphologic, published in 
1866, and reiterated with still greater emphasis in his Naturliche 
ScHopfungsgcschichtc, in 1868. Between this period and that of the 
appearance of the Descent of Man, Haeckel was exposed to the 
bitterest attacks, not only from the adherents of the Church and 
the opponents of Darwin generally, but from those adherents of 
Darwinism in Germany—and they were many—whose conception 
2 New York, 1845, ?• Is°- GENESIS OF MAN. 
7 
of it was limited to the body of principles contained in the Origin 
of Species. As in that work all reference to the position of the 
human race in the animal kingdom was carefully excluded, thus 
ingeniously avoiding the shock of prejudice which any such con- 
nection would have occasioned, the simplicity, the naivete, and, at 
the same time, the force of reasoning displayed in it, not only 
won the immediate assent of all fully emancipated minds, but 
took a strong hold upon great numbers of liberally educated per- 
sons whose independent reflections had not yet carried them wholly 
out from under the influence of theological conceptions. Among 
these were many thoroughly scientific men and naturalists, special- 
ists in the various departments of science, whose analytical labors 
had not left them time fora synthesis of the facts even within their 
own special branch of research. These accepted the conclusions 
drawn in the Origin of Species without perceiving that other and 
important ones might and must follow from the same premises. 
And because Haeckel drew these logical and necessary conclu- 
sions, these persons attacked him from all sides, and heaped upon 
him every form of accusation. Besides the charge above referred to 
of out-Darwining Darwin, and of going further than Darwin him- 
self would ever sanction, there was added the stronger one that 
Haeckel knew nothing about true Darwinism. The appearance in 
1871 of Darwin’s Descent of Man placed these anti-Haeckel Dar- 
winians in a most embarrassing situation, silencing many, convert- 
ing numbers, and driving not a few into the theological camp. 
But Haeckel emerged majestically from the battle, unscathed and 
undaunted. To charges of “ radicalism ” he had simply replied : 
“ Radical thinking is consistent thinking, which allows itself to be 
checked by no barriers of tradition or of enforced dogma.” To 
the confused outcry of the theological school and of the anti-Dar- 
winians in general, he did not deem it worth his while to reply. 
A satirical remark upon this class, however, is worth reproducing 
and might be ranked alongside of Darwin’s cutting sarcasm, 
wherein he says that he who scorns to be descended from a beast 
will generally reveal his descent in the act of sneering, whereby he 
will expose his canine teeth. “Itis an interesting and instructive 
circumstance,” says Haeckel, “that just those persons are most 
shocked and indignant at the discovery of the natural development 
of the human race from the apes, who, in their intellectual develop- 8 
GENESIS OF MAN. 
ment and cerebral differentiation, are obviously least removed 
from our common tertiary ancestors.” 
Both in his History of Creation and in his Ant]iropogeny, Haeckel 
has done a service to the cause of evolution by reviewing, in a fair 
and disinterested manner, the history of the origin and progress of 
those ideas which have culminated in the Darwinian theory. Let 
us glance for a moment at this history. 
Passing over the names of Wolff, Baer, Kant, Schleiden, Oken, 
and Humboldt, in Germany, of Buffon and Geoffrey St. Hilaire, 
in France, and of Dean Herbert, Professor Grant, Patrick Matthew, 
Freke, and Herbert Spencer (Essays, 1852), in England, all of 
whom had given more or less definite expression to these pro- 
gressive ideas prior to the appearance of the Origin of Species, it 
may be remarked that the great conception of the natural relation- 
ship (filiation) of all organic forms and their descent or development 
from common ancestors that have existed in more or less remote 
periods of the past, had a threefold independent origin in the minds 
of three men who were contemporary at the close of the last and 
the beginning of the present century, in each of the three great 
nations that now lead the intellectual world. These men were 
Erasmus Darwin, grandfather of the illustrious Charles, in Eng- 
land, Wolfgang Goethe, the great poet and philosopher, in 
Germany, and Jean Lamarck, in France. Wholly unacquainted 
with each other and with each other’s works, these three men, 
almost at the same time, gave utterance to substantially the same 
fundamental ideas, and elaborated in more or less extended and 
systematic form the essential ground-principles which now underlie 
the edifice of all progressive biological science. 
In his work entitled Zdonomia, published in 1794, Erasmus 
Darwin lays great weight upon the transformation of species 
of animals and plants through their own activities of life and 
through forced habituation to changed conditions of existence. 
It is a current remark, as applied to Charles Darwin, that he fur- 
nishes in himself one of the finest illustrations of “ development,” 
and thus of the truth of his own theory, that can be cited. Far 
more pointed, however, is the pleasantry of Haeckel, when, refer- 
ring to the grandfather of Charles as entertaining the germs of his 
grandson’s philosophy, and noting the striking circumstance 
that his father, though a respectable physician, exhibited no signs GENESIS OF MAN. 
9 
of having inherited these intellectual characteristics, he cites the 
case as a good example of “ atavism,” and remarks that “ Erasmus 
Darwin transmitted, according to the law of latent inheritance, de- 
finite molecular motions in the ganglion cells of his cerebrum to 
his grandson Charles without their manifesting themselves in his 
son Robert.” 
The importance of Erasmus Darwin’s views, however, mixed as 
they were with some vagaries and unbalanced speculations, was 
slight as compared with that which we must ascribe to those of 
Goethe. In his various essays and writings on “ Natural Science ” 
in general (1780), on Comparative Anatomy and Osteology (1786), 
on the Metamorphoses of Plants (1790), and in later works, he has 
wrought out a philosophy of organic life, which, when carefully 
analyzed and translated into the terminology now adopted, is found 
to contain, in their most general and fundamental form, the essen- 
tial principles of the Darwinian theory of development. A few 
passages wall illustrate this. In 1706 he wrote; “All the 
more perfect organic natures, under which we see fishes, amphib- 
ians, birds, mammals, and, at the head of these last, man, are 
formed according to one original type (Urbild), which in its dura- 
ble parts only deviates more or less, and is still daily being im- 
proved and transformed through propagation.” It is from this and 
other passages in which Goethe establishes his doctrine of an origi- 
nal type or image, which varies only slightly and in detail and not 
in plan, that the modern adherents of the theory of fixed types seem 
to have derived their chief arguments. Cuvier must have been con- 
versant with Goethe’s scientific writings, and he may have drawn 
largely upon them in founding his celebrated system of classifica- 
tion. But like some other great works that have become author- 
ity, those of Goethe are found, in some things, to admit of two in- 
terpretations, and to supply texts looking more than one way. The 
above passage, taken in connection with others, is now seen still 
more clearly to give countenance to what is now the powerful rival 
of the doctrine of types : viz., the doctrine of descent. In another 
place he says : “An internal original community (Gemcinschaft) lies 
at the bottom of all organization ; difference of form, on the contrary, 
arises from the necessary relations to the external world, and we 
may, therefore, with right assume an original, simultaneous varia- 
tion and an incessantly progressive transformation, in order to com- 
prehend the at once constant and deviating phenomena.” GENESIS OF MAN. 
To further explain this paradox he assumes two independent 
forces or impulses, working harmoniously together in nature, an 
internal formative impulse {innercr Bildungstrieb), and an external 
formative impulse (dussever Bildungstrieb). The former of these he 
also, in different passages, designates as the specific force (Specified- 
tionstrieb) and as the centripetal force ; the latter, on the other hand, 
he calls the modifying force or impulse of variation (Variationstrieb, 
and the centrifugal force. He also uses the term metamorphosis 
in a general (phylogenetic) sense as applied to the changes that 
take place in species and genera rather than in individuals. The 
following passage contains the kernel of this entire portion of his 
philosophy: “ The idea of metamorphosis is like that of the vis 
centrifuga, and would lose itself in infinity were there not a check 
offered to it; this check is the specific force (Specificationstrieb), the 
stubborn power of permanency {sake Bcharrlichkcitsvermbgen) of 
whatever has once become a reality, a vis centripeta, which in its 
deepest foundations can possess no externality.” 
If, now, we translate Goethe’s internal formative impulse, specific 
force, or centripetal force, by the modern term heredity, as we un- 
doubtedly may, and his external formative impulse, modifying force, 
or centrifugal force, by the modern term adaptation, as we may 
still more clearly do, we shall have, m Goethe’s philosophy of life, 
neither more nor less than the essential elements of the modern 
doctrine of descent. 
Of course, nothing is here found but the general principles ; the 
mode and the examples could not have been furnished in Germany 
when Goethe wrote. 
Haeckel, however, is abundantly justified in pointing to Ger- 
many’s greatest genius as having long ago given utterance to the 
most radical of his own doctrines and that for which he has re- 
ceived the severest animadversions, when, in the passage first 
quoted, he places man at the head of the mammalian class. And 
yet, who had thought of assailing Goethe with the charge of deriv- 
ing man from the apes ! 
With almost equal justice does Haeckel claim that, in the follow- 
ing and other passages, Goethe has not only declared the genea- 
logical relationship of the vegetable to the animal kingdom, but 
has furnished the nucleus of the unitary or monophyletic theory of 
descent. “ When we consider plants and animals in their most im- GENESIS OF MAN. 
11 
perfect condition they are scarcely to be distinguished. This much, 
however, we may say, that those creatures that now and then ap- 
appear, having relationships with plants and with animals difficult 
to separate, perfect themselves in two opposite directions, so that 
the plant at last glorifies itself in the tree, durable and fixed, the 
animal, in man, with the highest degree of mobility and freedom.” 
The ambiguity of Goethe’s language is due to the profundity 
and high generality of his ideas, coupled with a certain poetic 
vagueness so indispensable to his genius. In the former quality, 
though not at all in the latter, one is reminded of that profound 
and comprehensive analysis which, with all the materials of that 
later date (1866), and with the power of logic characteristic of 
England’s foremost philosopher, Herbert Spencer, in his Biology, 
(vol. 1, ch. xi., and xii.), has made of these same principles; a 
treatise, I may add, which Haeckel has indeed recognized,3 but 
upon which he could scarcely have failed to place more emphasis 
if he had been thoroughly acquainted with it. 
Quite different in method and character from Goethe’s contribu- 
tion to the theory of transmutation and descent was that of La- 
marck. Whatever his philosophy may have lacked in profundity, 
it was not open to the charge of ambiguity. All its shortcomings 
were amply compensated for by the wealth of illustration and the 
multiplicity of facts drawn directly from nature, which, as a life- 
long naturalist, he was able to bring to its support. In this respect 
(and this is after all the chief consideration), the now celebrated, 
though long neglected, Philosophic Zoologique is alone, of all the 
works that had preceded it or were contemporary with it, worthy 
of a serious comparison with the Origin of Species or the Descent 
of Man. And it is certainly a remarkable coincidence and may 
have for some readers, if no other, at least a mnemonic value, that 
the Philosophic Zoologique and the Origin of Species were separated 
by the space of just half a century, the former appearing in 1809, 
the latter in 1859. The interest of this circumstance is still further 
heightened by the fact that Charles Darwin 'was born in the year 
1809, the same in which the great precursor of his own works like- 
wise issued into the world ; as if its subtle influence had wafted 
across the channel and breathed its mysterious afflatus into the 
nostrils of the new-born herald of its principles! 
3 Schopfungsgeschichte, 5 Aufl. pp. 106, 657. 12 
GENESIS OF MAN. 
The dim intimations and scattered glimpses of Goethe and ot 
Dr. Darwin were insignificant in comparison with the lucid illus- 
trations and systematic arguments of the great French naturalist. 
After so many years of assiduous study Lamarck, as it were, but 
copied his conclusions from the pages of nature where facts stood 
forth like letters in a book. Yet none the less credit to his intel- 
lect, for was not this same book sealed to his great contem- 
porary, Cuvier, who knew its alphabet equally well ? And is it not 
sealed to many to-day ? The truth is that for the first time the 
causal and essentially rational type of mind had been joined in the 
same individual with those other qualities which impel to the pa- 
tient investigation of facts and details; rare combination, so success- 
fully repeated in the intellectual constitutions of Charles Darwin 
and Ernst Haeckel. 
When we compare, from our disinterested standpoint in America, 
the great chef d' oeuvre of Jean Lamarck, its systematic execution, 
its definite, avowed purpose, and its vast array of proofs from the 
only legitimate source of argument, with the various writings of 
Goethe containing his views on this subject, arranged with no sys- 
tematic order, having no well defined purpose, evincing no clear 
conception of nature’s means or methods, and manifesting a com- 
paratively scanty acquaintance with particular cases by which the 
laws under discussion are to be illustrated, we cannot fail to per- 
ceive, in the circumstance of Haeckel’s placing his own country- 
man before the son of a rival nation, in his estimate of the relative 
labors of the two pioneers of evolution, a trace of that almost 
inevitable national bias which lurks in regions of the brain inac- 
cessible to the invasion even of exact science. The essential 
incongruity between the first and last parts of the following passage 
will be apparent to all. “At the head of the French natural 
philosophy stands Jean Lamarck, who, in the history of the doc- 
trine of descent, next to Darwin and Goethe, occupies the first place. 
To him will remain the immortal glory of having for the first time 
brought forward the theory of descent as an independent scientific 
theory and established it as the natural philosophical foundation 
of all biology.” He certainly ascribes to Goethe no such “ im- 
mortal glory” as this. 
There is but one distinct element in Darwinism that is not also 
found in Lamarckism. This is the important recognition of the GENESIS OF MAN. 
law of competition among living organisms as a factor in develop- 
ment ; that principle which Darwin so forcibly expresses by the 
phrase “ struggle for existence.” Lamarck does indeed recognize 
this “ struggle ” and the influence it exerts in preventing the un- 
checked multiplication of any one species from rendering the globe 
uninhabitable to others. But he seems to regard this as a wise 
precaution and calculated “ to preserve all in the established order.” 
In other words, he recognizes it as a statical but not as a dynamical 
law. He fails to perceive its influence in transforming species. 
It is the full appreciation of this element that constitutes the real 
strength of Darwinism ; it is the key-stone of the arch of the 
descent theory, for the discovery and successful illustration of 
which too great praise cannot be awarded to the English naturalist. 
But every other important principle embraced in his Origin of Spe- 
cies was also contained in more or less definite form in the Philo- 
sophic Zoologique. 
The failure of Lamarck’s views to gain the ascendancy so rapidly 
attained by those of Darwin, was due to a variety of causes. First 
among these was the general fact that the state of science and pub- 
lic opinion had not, at his time, sufficiently advanced for the gen- 
eral reception of that class of ideas ; and any estimate of Lamarck’s 
works which leaves out their silent, leavening influence upon cer- 
tain classes directly, and thence indirectly upon society at large, 
is too hastily made and fails to do them justice. Next in impor- 
tance, in preventing the early spread of Lamarckism, comes the un- 
fortunate omission, above alluded to, to grasp the great law of bio- 
logical competion in its dynamic form. As a third influence may 
be ranked the somewhat direct and undiplomatic method of La- 
marck, which never consulted the policy of what he wished to say 
or courted the approval of high authorities. Every truth in his 
possession was put forward in the most direct and naked manner, re- 
gardless of the shock it might produce upon a world still groping in 
the murky atmosphere of teleology. Still a fourth element of weak- 
ness in the Lamarckian philosophy was the inadequate emphasis 
which he laid upon the most important of all his principles, that of 
heredity, and the correspondingly undue importance ascribed to 
habit, to use and disuse, as a direct agent in the modification of or- 
gans. The real failure here was to grasp the true connection and 
cooperation of these two principles. In short he seemed but dimly 14 
GENESIS OF MAN. 
to perceive the manner in which the inheritance of slight variations, 
however produced, and their transmission to successive generations, 
brings about, in the course of time, the transformation of some, and 
the extinction of other species. It is the clear conception and forci- 
ble presentation of this principle and its happy combination with 
that of the perpetual competition going on in nature, that gives 
to Darwin’s exposition that air of extreme probability and that 
power of universal conviction so characteristic of his works. 
The importance of this distinction between the methods of the 
two naturalists in expressing this conception may justify me in 
borrowing a few very appropriate terms from the Biology of Her- 
bert Spencer for its better illustration. We may then say that 
while Lamarck seemed clearly to comprehend the influence of the 
environment (milieu) upon the organism, and to attribute the results 
to this as the one great and sufficient cause, he failed on the one 
hand to take in the full scope of the environment, and on the other 
to conceive of all the susceptibilities of the organism. In his 
conception of the former he inadequately, if at all, appreciated the 
organic element, the influence of one organism upon another ob- 
jectively considered as a modifying force. In his notion of the 
organism and its susceptibilities he laid too great stress upon the 
principle of “ direct equilibration,” and comparatively little upon the 
far more important one of “ indirect equilibration.” To the readers of 
the Philosophic Zoologique it seemed a crude, to many a ridiculous, 
explanation of the length of the fore-limbs and neck of the giraffe, 
that they had become elongated by perpetual attempts to reach 
the branches of trees that lay beyond the reach of other animals; 
and while he admits that this could not have been accomplished 
by the efforts of any single individual, and ascribes it to a series of 
cumulative efforts through many generations, thus clearly recog- 
nizing and expressly affirming the influence of heredity, he yet 
fails to show the way in which this influence must have been ex- 
erted, its modus operandi. He does not say, for example, that the 
great elongation referred to was initiated in some remote ancestor 
by some slight variation in this direction, either accidental or per- 
haps due to the animal’s efforts; that this variation, proving ad- 
vantageous and being transmitted to a numerous progeny, rendered 
their chances of survival in critical periods greater than those of 
such as possessed no such peculiarity; that this power of survival, GENESIS OF MAN. 
due to this inheritable peculiarity, became thus a constant force 
which, through the interbreeding of those possessing it, tended to 
increase this variation, until in the course of generations it resulted 
in differentiating the giraffe in the special attributes of length of 
cervical vertebra; and of anterior limbs, and in giving it its present 
anomalous position among antelopes. Instead of this, Lamarck says: 
“ With reference to habits it is curious to observe their results 
in the peculiar form and figure of the giraffe (camelo-pardalis). 
It is known that this animal, the tallest of the mammals, inhabits 
the interior of Africa, and that it lives in places where the earth, 
almost always arid and without herbage, compels it to browse 
upon the leaves of trees and to be continually exerting itself to 
reach them. From this habit, long maintained in all the individ- 
uals of its race, it has resulted that its fore-limbs have become 
longer than its hind ones, and that its neck has become so much 
elongated that the giraffe, without rearing upon its hind feet ele- 
vates its head and reaches to the height of six metres, (nearly 
twenty feet).”4 It will be observed how in this reasoning (and it is 
so throughout), Lamarck passes from the observed fact directly to 
the original cause, leaving out the intermediate steps which it is 
necessary to supply in order to conceive of the manner in which 
the results are produced. Now, it is precisely this part of the ar- 
gument that mankind in general require before they are willing to 
give in their adhesion to a theory. They say: “it all looks plau- 
sible enough, but you fail to show us how it actually takes place.” 
As in his illustrations, so in his general “ laws,” Lamarck fails to 
grasp the principle of Natural Selection. His first great law is 
expressed in these words : “ In every animal which has not passed 
the limit of its developments, the frequent and sustained use of 
any organ little by little strengthens, develops, and enlarges this 
organ, and gives it a power proportionate to the duration of this 
exercise; while the constant failure to use such organ insensibly 
enfeebles and deteriorates it, and progressively diminishes its capac- 
ities, causing it finally to disappear.”5 His second law is as fol- 
lows : “All that nature has caused individuals to acquire or lose 
through the influence of the circumstances to which their race has 
been long exposed, and consequently through the influence of the 
4 Phil. Zoo., Tome I, p, 254. Paris, 1873. 
5 Loc. cit., p. 235. GENESIS OF MAN. 
predominant exercise of any organ, or through that of a constant 
failure to exercise any part, it preserves through inheritance (<gene- 
ration) in the new individuals that proceed from them, provided 
the changes acquired be common to both sexes, or to those which 
have produced these new individuals.”6 
Whatever may be lacking in these two laws, there is certainly 
contained in them a clear expression of the two prime factors of 
the theory of descent: viz., heredity and variation ; or, as Darwin 
frequently expresses it, “ descent with modification.” The elements 
of availability alone are wanting ; those working principles by 
which the theory was to be erected into a perfect system and its 
machinery set into running order. 
A grand stride had been made, the doctrine of fixity of species 
had received a fatal thrust, the special creation hypothesis was un- 
dermined, teleology thenceforth was in organic nature doomed. 
A fifth and last element of weakness in the Lamarckian philoso- 
phy may be enumerated, one which Haeckel justly sets down to 
the greater credit of the illustrious author as indicating how far he 
had outstripped the intellectual progress of his age, so that it was 
practically impossible that his views should have been accepted in 
his own day. This consisted in the acceptance and express enun- 
ciation of two doctrines which are still to-day deeply involved in 
controversy, even among the most advanced scientific men of our 
times; that of spontaneous generation and that of the simian ances- 
try of the human race, embracing in the latter the extreme theory 
of the development of the mind pari passu with that of the nervous 
system and the brain, and carrying it out to the logical consequence 
of denying the freedom of the will, in the current sense of the 
phrase. These were clearly, in Lamarck’s day, shocking and atro- 
cious doctrines, and it is doubtless to these chiefly that is to be 
attributed the neglect of his great contemporary, Cuvier, to give 
the Philosophic Zoologique as much as a passing notice in his report 
on the progress of natural science; as well as the rebuke of his 
philosophical views which he saw fit to introduce into his “ eloge ” (?) 
of the great scientific labors of Lamarck. He little dreamed that 
when these utterances should have been forgotten, and the works 
of Cuvier consigned to the musty shelves of antiquarian libraries, 
the humble effort which he had first disdained to notice and after- 
6 Loc. cit. GENESIS OF MAN. 
17 
wards noticed with a reproach, would emerge from its long obscur- 
ity, and, in new and modern dress, find its way to thousands of book 
tables, as the classic foundation of a great progressive philosophy. 
With regard to Lamarck’s views on the subject of spontaneous 
generation, it is due to him to say that he did not espouse any of 
the crude conceptions which had been maintained on the authority 
of Aristotle among the scholastic metaphysicians. He repeatedly 
asserts that it is only the most imperfectly organized beings that 
could be directly produced by the forces of inorganic nature, and 
while he could have had but a faint idea of the extreme imperfec- 
tion of these lowliest creatures, still as only the least perfectly or- 
ganized could, according to him, become the products of spontaneous 
generation, his careful language on this point completely exempts 
him from the charge of entertaining gross notions about the origin 
of life. Haeckel, with his intimate acquaintance with the lowest 
known forms of organic existence, his monera, does not hesitate to 
declare the necessity of a transition, at some period, from the inor- 
ganic to the organic condition; nay, more, he believes that these 
monera are directly evolved, by the mechanical agencies of nature, 
out of inorganic carbon compounds, and that protoplasm, of which 
alone these creatures consist, is the initial stage of organic life. 
With Lamarck, as with Haeckel, it is the logical necessity, rather 
than any empirical discovery, that renders this doctrine indispen- 
sable as a starting point and first link in the chain of organic devel- 
opment. As the latter justly remarks, unless we do this the natu- 
ral explanation is given up, and there remains no alternative but to 
fall back upon the supernatural. Herbert Spencer, too, indepen- 
dently of his theory of physiological units, has felt the force of this 
a priori argument, and has ranged himself on the side of complete 
consistency. Neither need the teleologists exult at the apparent 
overthrow, just now so imminent, of the results of Bastian’s experi- 
ments. From such a result we shall only the better learn how na- 
ture works, and no adherent of the doctrine of archigonia will the 
less maintain that life must have had a beginning upon the planet. 
Lamarck leans to the assumption of a perpetuul series of such be- 
ginnings which are still going on in the present as in the past, a 
constant play of the originating force. Haeckel admits as much 
for protoplasm and for his monera ; beyond this he says it does not 
concern the theory of descent to go. Darwin, with his character- GENESIS OF MAN. 
istic diplomacy, never lifts the dark curtain that hangs between 
the organic and the inorganic world. 
Professor Haeckel is not only an original investigator, but also an 
original thinker. Primarily a specialist and investigator of the 
minute histology of living organisms, there is combined in his 
mental constitution, along with this indispensable talent, a large 
development of causality which renders it impossible for him to 
stop with the mere elaboration of details and the simple accumula- 
tion of facts. To him every fact is one of the terms of a proposi- 
tion, and every collection of related facts becomes an argument, 
while the sum total of his knowledge of those minute creatures 
which he has made a life study constitutes in his mind a philoso- 
phy. He is at once an investigator and a philosopher. To the 
former quality, his numerous monographs of the lower invertebrates 
sufficiently testify. His monograph of the Radiolaria (with an atlas 
of thirty-five copper plates), of the Gcryonidae, of the Siphonopora, 
but especially of the calcareous sponges, belong to the minutest 
and most exhaustive histological researches of modern zoology. 
In all these, but particularly in the last named, the author has con- 
stantly before him a theorem to demonstrate. He expressly 
avows that his investigations into the calcareous sponges were 
undertaken with a view to an analytical solution of the problem of 
the origin of species. He seems not to have feared thus to invite 
the charge of having resolved, in this investigation, to verify the 
argument of Darwin, the perusal of whose great work had induced 
him to undertake it. Nor does he fail to prove all he hoped to do. 
On the contrary, he claims to have overwhelmingly established all 
the principal claims of his English contemporary. The objection 
had been raised that the Darwinian theory did not rest upon a suf- 
ficient body of observed facts ; that it was a mere plausible synthe- 
sis from a too meagre analysis. Haeckel holds up his two volumes, 
containing the results of his five years of indefatigable labor on 
these lower organisms, and his atlas with its sixty carefully drawn 
plates, all elaborated from the most abundant materials from all 
parts of the world, and challenges the scrutiny of his scientific op- 
ponents. The doctrine of the fixity and invariability of species, al- 
ready reeling under the blows of Lamarck and Darwin, he claims, is 
therein completely demolished. He proves that in this group of ani- 
mals the number of genera and species depends altogether upon the GENESIS OF MAN. 
19 
meaning which each naturalist may happen to attach to these terms. 
He may class them all under one genus with three species, or under 
three genera with twenty-one species, or under twenty-one genera 
with 111 species, or under thirty-nine genera with 289 species, or 
even under 113 genera with 591 species, according as his concep- 
tion of genera and species be wide or narrow. In fact, the 591 dif- 
ferent forms may be so arranged in a genealogical tree that the 
ancestry of the entire group can be traced back to one common 
form from which all the rest must have descended, undergoing the 
modifications induced by the varying conditions of their existence. 
This common ancestor Haeckel believes to be the Olynthus. 
Thus, the long respected and miraculously created bona species 
is histologically demonstrated a myth. 
Rising from the special towards the general, the Generclle 
Morphologic may be next named. It was the first systematic 
attempt to establish the theory of development from the or- 
ganized facts of comparative anatomy. But the most popular, in its 
subject matter and style, of the works of Professor Haekel is his 
Natiirliche Schbpfungsgeschichte, consistiong of a course of lectures 
upon the questions in general opened by the Origin of Species, 
but containing the advanced views of the author, already re- 
ferred to. This work is, therefore, of the highest interest to the 
general public, and cannot be too strongly recommended. It is 
divided into five parts designated by the author with the following 
titles, respectively, each of which sufficiently characterizes its con- 
tents: 1, Historical Part; 2, Darwinistic Part; 3, Cosmogenetic 
Part; 4, Phylogenetic Part; and 5, Anthropogenetic Part. 
His Anthropogeny or History of the Devclopnmit of Man, to 
which we will now confine our attention more closely, is simply an 
enlargement and expansion of the last part of the History of Crea- 
tion. The greatness of the theme required this, and no one who 
carefully follows the author through this work will complain that 
justice has not been done the subject. As may well be imagined 
this work covers the most interesting field of investigation and in- 
troduces the reader into the most mysterious penetralia of nature. 
The charm of its diction, the fullness of its illustrations, and above 
all the perpetual wonderland through which it leads, entitle it to 
take rank at once among the most instructive and the most fasci- 
nating works to which modern science has ever yet given birth. GENESIS 0E MAN. 
“The proper study of mankind is man.” And yet how tame 
appear the most mysterious facts of human anatomy and physi- 
ology, as taught to the mass of mankind, compared with the as- 
tonishing revelations of comparative embryology and comparative 
anatomy ! 
As already remarked, Haeckel is a philosopher as well as an in- 
vestigator. No German philosopher can be without his terminology. 
Haeckel has his, and it remains to the future to decide whether the 
ends of science are to be furthered by its introduction. It is at 
least certain that to understand Haeckel one must understand his 
terminology. Being much of it of Greek derivation, it undergoes 
little change by transfer to the English language. In so far, how- 
ever, as it is German, this difficulty is great, often, indeed, quite 
insuperable. Everybody admits the inadequacy of some parts of 
Darwin’s terminology. The best English expounders of his theory 
have found themselves compelled to adopt other terms to convey 
his ideas with the requisite clearness and force. I have already 
referred to important improvements introduced by Herbert Spen- 
cer before it was possible for him properly to arrange the new 
biological laws under his universal system of cosmical principles. 
That author has also, in addition to those before referred to, pro- 
posed an excellent synonym for Darwin’s most important term, 
“ Natural Selection.” This he calls “ Survival of the fittest,” 
which, while it can never of course supersede the former, must be 
admitted by all to bring to the mind far more directly, the idea 
which it is desired to convey. 
Haeckel has felt the need of some adequate terms to characterize 
the two great classes or types of mind, which not only now, but in 
all ages, have existed in a state of opposition or rivalry in the 
world. No matter what questions might arise for solution bearing 
upon the knowledge or progress of the race, there has always ex- 
isted this sharply defined opposition growing out of these two 
constutionally opposite mental types. Various popular appella- 
tions have been employed from time to time, differing in different 
countries and for different forms of agitation. None of these, how- 
ever, have struck at the true psychological root of the phenomenon, 
and the world has been long waiting for a thorough analysis of this 
subject and the suggestion of a scientific terminology, based upon 
this ground-law of the constitutional polarity of the human intellect. GENESIS OF MAN. 
21 
That Haeckel has fully supplied this want I would not venture 
to affirm, but that he has made an important contribution towards 
such a consummation cannot be questioned. “ If,” says he, “ you 
place all the forms of cosmological conception of the various peo- 
ples and times into comparative juxtaposition, you can finally bring 
them all into two squarely opposing groups : a causal or mechani- 
cal, and a teleological or vitalistic group.” 
The first of these groups, by requiring every phenomenon to be 
conceived as the mechanical effect of an antecedent true cause 
(causa cjficicns), necessarily erects a cosmogony that is bound to- 
gether throughout by an unbroken chain of mechanically depend- 
ent phenomena. Such a universe is a unit, and throughout its 
domain there can pervade but one universal law. This all-pervad- 
ing homogeneous law is the monistic principle or force, while 
the whole theory which thus conceives of the universe is termed 
by Haeckel, indifferently, the monistic, and the mechanical theory 
of the universe. Only those minds that are imbued with this con- 
ception as a fundamental quality of their cerebral constitution are 
capable of appreciating, or of subscribing to the Darwinian and 
Lamarckian philosophy, which is simply the monistic principle 
applied to biology. This class has formed in all ages and countries 
the progressive and reformatory element of mankind. 
The teleological or vitalistic group, on the other hand, conceive 
of all phenomena as produced by a power either outside of nature 
and acting upon it, or consisting of Nature regarded as a conscious 
intelligence, and which, in either case, directs everything for an 
ordained purpose or end (causa finals'). This recognition of a 
cause independent of phenomena renders the operations of nature 
dual, and is designated by Haeckel as the dualistic conception, 
and the body of such conceptions as the dualistic philosophy. All 
teleological conceptions are, of necessity, dualistic, just as all causal 
conceptions are necessarily monistic. The distinction between teleo- 
logical and theological conceptions vanishes as soon as we class 
the pantheists among theologists. This class is the great conser- 
vative element of mankind, who, looking upon nature as under 
the control of Omnipotence, logically resign all effort either to do 
or to know into its hands. 
Haeckel also employs the term dysteleology in antithesis to 
teleology, and frequently uses it as a general term to designate 
the monistic or mechanical philosophy. 22 
GENESIS OF MAN. 
The entire body of principles embraced in the Lamarckian, Dar- 
winian, and Haeckelian philosophy, when regarded as having passed 
through its hypothetical and theoretical stages, takes the form of a 
science, and receives the very 'appropriate name, History of De- 
velopment (.Entwickelungsgcschichtc), a term adopted by Von Baer 
and applied to embryonic development, but extended by Haeckel 
to embrace also the secular development of specific forms. This 
twofold application of the term History of Development, suggests 
the natural division of the science into its two great departments. 
The first of these is essentially that of Von Baer, and treats of the 
progress of the individual organism from the earliest embryonic 
condition throughout the numerous successive stages and trans- 
formations through which it passes until it arrives at the perfect 
state. Properly it does not stop at birth, but continues through 
life, during which, in many creatures, very important metamorphoses 
take place. This division of the History of Development is de- 
nominated Ontogeny. The other grand division, which treats of 
the development of present living forms out of antecedent forms 
through the influences of heredity (Vererbung) and adaptation 
(.Anpassung), is termed Phytogeny, a term derived from the Greek 
word <poXuv, a race. 
It is to this latter branch of the History of Development that 
the attention of progressive minds has been heretofore almost ex- 
clusively directed, and the arguments of Lamarck and Darwin have 
been chiefly drawn from considerations of comparative anatomy, 
of geographical distribution, and of paleontology. The powerful 
re-enforcement which it has now received from ontogeny was quite 
unexpected, and the astonishing uniformity with which the onto- 
genetic facts support, confirm, and corroborate the phylogenetic 
arguments, may be regarded as having placed the doctrine of 
development beyond the stage of theory and speculation, and 
established it as the first law of Biology. 
Although the chief facts of ontogeny had been discovered and 
recorded by Von Baer and others, a quarter of a century before, it 
was left for Haeckel to first perceive and announce their relation to 
the law of phylogenetic development, and to urge their irresistible 
force as arguments for the theory of descent. Von Baer himself, 
although he had erected them into a “ History of Development,” 
seems but dimly to have realized the significance of these embry- GENESIS OF MAN. 
23 
onic metamorphoses which he has observed and described, and as 
recently as the date of the late Professor Agassiz’ public lectures, 
is quoted by him in a private letter as still adhering to his doctrine 
of types, and protesting against that of descent from the apes.7 
Anthropogeny, or the Genesis of Man, considers all the argu- 
ments, both from ontogeny and from phylogeny, in support of the 
assumption of the descent of the human race in a direct line from 
the lower animals, shows throughout the length of this line what 
creatures now existing upon the globe or found fossil in the rocks, 
stand nearest to this line of descent, and aims to trace the pedigree 
of the being who is the present undisputed lord of the planet back 
to the lowest amoeba, and even to the moner. Haeckel does not 
stop with the ape, with the amphioxus, or even with the ascidian. 
Guided by the Ariadnean clew of ontogenesis, he pursues man’s 
genealogy back through the labyrinth of primordial forms into the 
cell, and thence still back until he loses it in protoplasm. 
Standing, as man does, at the head of the animal kingdom, and 
forming the last and highest stage of development upon the globe, 
the history of his progress from the lowest form of organic exist- 
ence must be co-extensive with that of all other beings. It differs, 
however, from the history of development in general, in not being 
concerned with any of the branches that diverge at various points 
from the main anthropogenetic stem. This becomes obvious when 
we commence to study phylogeny, but may be noted here as a 
means of better appreciating the true scope of Anthropogeny. 
A few illustrations will make it clear. 
Not to speak of the entire vegetable kingdom which is lopped 
off at the first stroke, we find, as we ascend the scale, that one after 
another the great branches of the Zoophytes, of the Annelids (in- 
cluding all the Articulates and the Echinoderms), of the Mollusca, 
of the Fishes, of the Reptiles, of the Ungulata and Cetacea, of the 
Carnivora and Rodentia, and of many other less important groups, 
are successively passed by and left behind ; thus obviating the ne- 
cessity of following out the special genealogy and development of 
each of these complicated divisions of natural history. The his- 
tory of development of man pushes right on, taking such notice 
only of divergent trunks as is necessary to fix with certainty the 
position of his line of march. 
? Since the above was written, the death of Von Baer has been announced. His 
last effort was in the nature of a systematic attack on Darwinism. 24 
GENESIS OF MAN. 
11. 
ONTOGENESIS. 
THE primary law of ontogenesis and that which connects it 
with the modern theory of development, is founded on the 
discovery of Von Baer, that the different successive stages of the 
embryonic development of the higher animals bear a singularly 
close resemblance to certain lower animals in their adult state, and 
that the embryos of many animals, and of man himself, in their 
earlier stages, are scarcely distinguishable from one another. This 
fact, as already remarked, was carefully studied by Von Baer, and 
the successive stages of embryonic life systematically compared 
and co-ordinated. In his great work on the History of Develop- 
ment of Animals, (1828-1837), that distinguished embryologist has 
given to the world the results of his exhaustive investigations. In 
this work he announces that the theory of types founded by Cuvier 
in 1816, upon the facts of comparative anatomy, is confirmed by 
those of embryology, and shows that the process of development, 
which is the same for all the animals of any of the four types, is 
different from those of different types. 
Haeckel does not gainsay the general truth of this statement, 
but simply shows that it cannot be used as an argument against 
the theory of descent, as Von Baer’s investigations were confined to 
fully differentiated animals of each type, and not extended to the 
then little known Amphioxus and Ascidians, which later researches 
have shown to constitute transition forms uniting two types. Be- 
sides, as we shall see, however different the course of development 
of different animals may be, the embryos of animals of higher 
types pass through phases identical with the adult forms of some 
of the lower types, though not of others, showing that the four 
types of Cuvier and Von Baer—Radiates, Articulates, Mollusks 
and Vertebrates—can neither be regarded as co-ordinate, nor as 
regularly subordinated to each other. And this is not all: Von 
Baer’s own facts, and those of many embryologists, show that there 
must be another type added to these four ; viz, the Protozoa, and that 
from this the course of both phylogenetic and ontogenetic develop- 
ment has been through the Worms directly to the Vertebrates, leav- 
ing the remaining types untouched. It seems, therefore, simply GENESIS OF MAN. 
25 
that the different branches of the main stem have in our time 
spread so widely, and become so far differentiated by adaptive in- 
fluences, that even their embryos have lost many of the original 
traces of relationship. The important fact remains that within the 
vertebrate type, as within other types, the embryonic stages cor- 
respond with wonderful accuracy to the successively ascending 
classes and orders established for that type. 
The law of Von Baer, expressed in the most general terms, as 
laid down by himself, is in these words : “ The development of an 
individual of a definite animal form is determined by two relations: 
first, by a progressive development of the animal body through in- 
creasing histological and morphological differentiation (Sonderung); 
secondly, through simultaneous progressive development from a 
more general form of the type to a more special. The degree of 
development of the animal body consists in a greater or less 
amount of heterogeneity of the elementary parts and of the indi- 
vidual components of a composite apparatus ; in a word, in the 
greater histological and morphological differentiation. The type, 
on the contrary, is the fundamental relation of the organic elements 
and organs.” 
Upon this important law, Haeckel puts the new interpretation 
that the “type” of Von Baer is the representative of the law of 
heredity of Darwin, (the vis centripeta of Goethe), while the “ degree 
of development ” means neither more nor less than his law of 
adaptation (Goethe’s vis centrifuga). 
The parallelism which is found to exist between the facts of 
ontogenesis and the facts of phylogenesis, between the embryonic 
forms of higher, and the adult forms of lower, organisms, is one of 
the most astonishing discoveries which science has ever made. 
It is one which would have been least likely ever to be reached 
by conjecture or by any form of a priori reasoning. There was 
but one possible mode of reaching this truth, and this was by 
long and patient investigation of the minutest objects and most 
occult phenomena, without the aid even of a “ working hypoth- 
esis.” 
Such a truth must have a meaning. This meaning Von Baer 
himself never realized and, when pointed out to him by others, never 
accepted. Yet I venture to predict that no unbiased reader of 
Haeckel’s Anthropogenie will any longer doubt the justice of his 26 
GENESIS OF MAN. 
conclusions respecting the significance of this marvellous co-inci- 
dence. The believers in miracles, who refuse to accept this ex- 
planation, will have discovered the most miraculous of all miracles. 
The singular alleged action of Providence in stirring fossil shells 
and bones into the earth, of which the mountains were made, “ as 
a cook stirs raisins into a pudding,” would be an intelligible phe- 
nomenon compared with this. That a man should begin his 
existence as an amoeba, should subsequently turn into a worm, a 
little later should become a lamprey, later still a fish, and after pass- 
ing through amphibian, reptilian, monotreme, marsupial, lemurian, 
and simian forms, should at last emerge with the human shape,— 
this series of remarkable metamorphoses, if required to be explained 
on the assumption that it is directed by the arbitrary will of the 
Creator, would furnish a more fatal stumbling-block than even 
the presence of those useless and usually deleterious rudimentary 
organs, which all higher animals are found to possess. For 
even if we can bring ourselves to comprehend how the Creator 
may, for some inscrutable reason, introduce many arbitrary irregu- 
larities into his handiwork, according as he may be actuated by 
this or that caprice, we are still at a loss to understand how he 
should wish to carry on a whole system of freaks in the embryo, 
which have a manifest correspondence with the mature forms of 
life known to exist upon the globe, unless there be some causal 
connection between the two systems. Nothing short of the most 
complete abnegation of reason, nay, of a strong effort to accept 
the unreasonable, can prevent the mind, cognizant of these two 
series of facts, from becoming thoroughly convinced that such a 
dependence must subsist. 
The science which embraces both the ontogenetic and the phy- 
logenetic development of life, the genesis of life in general, is called 
by Haeckel Biogcnia, a science, as he remarks, as yet scarcely 
founded. The law which expresses the relation between the 
facts of ontogeny and the facts of phylogeny is, therefore, the 
fundamental law of biogcnia. Stated in the most direct manner, 
this law is that “ phylogenesis is the mechanical cause of ontogene- 
sis.” From a somewhat altered point of view, the same idea is 
conveyed by saying that ontogenesis is a brief recapitulation of phy- 
logenesis, or, that the history of the germ (Kcimcsgeschichte) is an 
abridgment ox epitome of the history of the race { Stammcsgeschichte). GENESIS OF MAN. 
2 7 
Mathematically enunciated, the germ-development becomes a 
functio?i of the race-development, so that every differentiation of 
the latter carries with it a corresponding and consequential differ- 
entiation of the former. This is the fundamental law of organic 
development, the great biogenetic ground-principle, to which the 
student of the history of development, whether of its ontogenetic or 
its phylogenetic aspect, must continually recur. The law of 
heredity, which Goethe calls “ the stubborn power of permanency in 
whatever has once possessed reality,” while it graciously yields to 
the influence of surrounding circumstances and admits of progress, 
nevertheless requires, with all the rigor of sovereignty, that every 
step forward shall be taken through the established channels, and 
with due respect for the most ancient forms. The human germ may, 
indeed, develop and perfect itself in the highest form of organized 
existence, but the old and time-honored fish-form and worm-form 
and amoeba-form, nay, even the moner-form, must be respected, and 
the proud man-germ must humbly bow to the inexorable decree of 
Nature, and must undergo this manifold and repeated metempsycho- 
sis, which in its strange reality eclipses all the dreams of Thales 
and Pythagoras. 
Phylogenesis, which is a cause, begins with the moner; onto- 
genesis, which is a consequence, begins with the cell. For man, 
as for all animals that have advanced beyond an extremely low 
stage of existence, there is but one mode by which new individuals 
of the race can be created and the race itself perpetuated, and that 
is by the contact of two germinal principles having opposite sexual 
polarities. Each of these principles is a simple cell. The male is 
the sperm-cell, the female the germ-cell. Only by the union and 
literal blending of these two cells can generation take place, 
The cell is the lowest organized form of existence. It is also 
the last term in the histological analysis of the tissues of the body. 
An animal is ultimately nothing more than an organized assem- 
blage of cells, a compound individual. 
The moner is a lower form of existence than the cell, the low- 
est known form, and may be distinguished as a wholly unorganized 
and undifferentiated individual. 
There are but two essential properties of a cell, a central nucleus 
and surrounding protoplasm. The only organization, the only differ- 
entiation, is that which distinguishes these two substances. And 28 
GENESIS OF MAN. 
this is itself very slight. Chemically, they can scarcely be dis- 
tinguished. Both consist of a carbon compound, containing a 
certain proportion of nitrogen, and belong to the albuminous group, 
of which all animal tissues are principally composed. The nucleus 
is generally of a darker color, but sometimes of a lighter, and may 
or may not contain in its centre a minute dot—nucleolus. It also 
may or may not be surrounded by a membranous envelope. This 
is generally present in the cells of plants, while it is generally ab- 
sent in those animals. 
The form of cells differs according to the circumstances of their 
existence. They are the most plastic and easily modified by ex- 
ternal conditions of all organized beings, and therefore make the 
best subjects for the study of the law of adaptation. Stationary 
cells in a motionless medium are uniformly spherical. When sub- 
jected to pressure they assume hexagonal, elongated, or compressed 
forms, according to the nature of the pressure. Cells that are 
active in a liquid medium have a portion of the matter composing 
their outer parts extended into a caudal appendage away from the 
direction of motion. In addition to the forms named, cells fre- 
quently assume others, sometimes taking wholly amorphous shapes, 
resulting from the particular conditions to which they may be sub- 
jected. They frequently change their form, and this not only from 
external influences, but in obedience to internal or subjective de- 
terminations. For a cell is a living creature. It possesses all the 
essential characteristics of an organized individual. The only 
functions necessary to characterize a living being are nutrition and 
propagation. Both these the cell possesses. It grows by the 
absorption of nourishment from the medium in which it lives. 
Where this nourishment is not uniformly mingled throughout the 
medium, but exists in the form of scattered solid particles, the cell 
acquires the power to extend portions of its substance into tempo- 
rary organs of grasping (pscudopodia), and thus to enclose and 
devour its food. It thus improvises a mouth and jaws on whichever 
side it may need them, and feeds itself after the manner of another 
animal. 
The cell propagates, like many much higher organisms, by 
division, or fission. It continues to take nourishment and to grow 
until it reaches the limit fixed by heredity for its size, and then, 
instead of growing larger or of ceasing to take food, it divides into GENESIS OF MAN. 
29 
two distinct cells. Each of these then goes through with the same 
process of nutrition and division, and so on. 
But besides these two essential phenomena, which are common 
to all life, whether animal or vegetable, the cell performs two other 
truly animal functions. It possesses the power of locomotion, and 
the faculty of sensation. Cells with caudal appendages, called 
lash-cells (Geisselzellen), have acquired that form in consequence of 
their independent activities in their liquid medium. Various other 
forms are traceable to similar causes. As a proof of the posses- 
sion by cells of a faculty of sensation, we have only to consider 
the efforts of various kinds to obtain their food. Some are actu- 
ally carnivorous, and show a certain degree of dexterity in captur- 
ing their prey. They are, therefore, not only capable of feeling, 
but, in a qualified sense, of thinking and of reasoning. 
There is no essential difference between the sperm-cells and 
germ-cells of higher animals, and the simple cells of which many 
lower animals consist, and beyond which they never advance. We 
can only say that among the infinitely varied forms of life we find 
that while most creatures have developed into highly compound 
states, and only revert to the original unicellular condition at the 
beginning of each individual’s existence, there are still many crea- 
tures that never progress beyond this primordial stage, and whose 
entire existence is passed in the form and condition of simple cells.8 
Among such creatures may be named the Amoebae, the Gregarinae, 
the Infusoria, etc. These animals, as well as those which consist 
simply of an accumulation or aggregation of cells, such as the 
Labryinthuleae, etc., and which form the second stage of develop- 
ment, never rising above the cellular condition, are classed by 
Haeckel, together with his Planaeada, in a grand-division or depart- 
ment by themselves, and called Protozoa. A further ground for 
this classification will be seen later. 
According to the fundamental biogenetic law above stated, the 
cell must be the primordial form out of which all more highly1 
organized beings, including man, have developed, since it is the 
original stage of their ontogenetic development. And as there 
still exist unicellular beings resembling the sperm-cells and the 
8 A complete description, both popular and systematic, of all the unicellular organ- 
isms known to exist, was published by Prof. Haeckel in 1878, entitled Das Protisten- 
reich, of which he has kindly sent the writer a copy. 30 
GENESIS OF MAN. 
germ-cells of higher organisms, the deduction is warranted that all 
higher creatures are the descendants of some form of these unicel- 
lular beings. Considering the differences that may and do exist 
even in cells, and in animals consisting of a single cell, Haeckel 
is led to the conclusion that of all the unicellular creatures known 
to science, the Amoeba bears the strongest evidence of being the 
original progenitor of the human race. 
The history of the discovery of the human ova and spermatozoa 
deserves a brief notice. In 1672, De Graaf discovered the Graafian 
vesicle, which he supposed to be the ovum itself. In 1797, Cruik- 
shank, Prevost and Dumas found and described the true ovules, 
but failed to comprehend their real nature and importance. It was 
left for Von Baer, thirty years later, to complete the discovery, and 
place it before the world in its full light. Purkinje (1825) and 
Wagner (1835) added important contributions in the discovery of 
the germi native vesicle or nucleus, and the germinative dot or nu- 
cleolus. The fact that the ova are simple cells could not be recog- 
nized until after the founding of the universal cell-theory by 
Schleiden (1838) and Schwann (1839). It was then perceived that 
eggs themselves are cells, differing in scarcely any respect from the 
cells of other tissues. 
The discovery of the spermatozoa, or male seminal animalcules, 
was first made by Leeuwenhoek in 1674, and confirmed by Louis 
Ham in 1677. A long war arose between the so-called Animalcu- 
lists and Ovulists, the first of which believed that the animalcules 
were the true and only germs of the future being, which simply 
found in the ova a suitable matrix for their development, while the 
latter maintained that the ova were the true germs, which were 
only affected with a germinative impulse by contact with the sper- 
matozoa. The real nature of this mysterious process has only 
been clearly brought to light by the labors of more modern inves- 
tigators, among the foremost of whom must be ranked Prof. Ernst 
Haeckel, of Jena. 
The ova of all mammals are identical in all essential character- 
istics. They all possess both nucleus and nucleolus, are of a 
spherical form, and about one-tenth of a line in diameter, and all 
acquire at maturity a membranous envelope called the chorion or 
zona pellucida. The egg of a mouse and that of an elephant can- 
not be distinguished from each other or from the human ovum in 
any respect. They are all simple cells. GENESIS OE MAN. 
The sperm-cells of mammals possess a no less marked similarity, 
They are exceedingly small as compared with the germ-cells, and 
possess long filiform caudal appendages. The chorion is wanting. 
Their form may be divided into head, body and tail, but between 
no two of these parts can there be said to exist any clear line of 
separation. The head contains the nucleus surrounded by proto- 
plasm or cell-substance, which is carried backward in gradually 
diminished quantity, forming the remaining portions. It was not 
until the year 1873 that it was discovered that these important or- 
ganisms, like the female ova, were simple cells. This discovery is 
in great part due to Prof. Haeckel’s own investigations. 
We may now consider the immediate consequences of the union 
of the sperm-cell with the germ-cell. The spermatozoon penetrates 
the many times larger ovum, making its entrance through minute 
pores in the chorion, and mingling at once with the germinative 
matter of the cell. A remarkable change takes place. Two per- 
fect cells with opposite sexual polarities have been drawn together 
by their inherent affinities. They have met and their substances 
have commingled. They literally blend into one individual. But 
that individual is no longer a cell. The sperm-cell has lost its in- 
dividuality and wholly disappeared. The nucleus of the germ- 
cell has likewise entirely vanished. The entire interior of the 
original cell has become a homogeneous mass of protoplasm, no 
longer possessing any traces of organization. Only the chorion 
remains to determine its original form. It is a case of retrogres- 
sion (Riickbildung), of reversion to the lowest type of existence. 
The human being who, as represented in sperm-cell and germ-cell, 
stands on the plane of the amoeba and the infusorium, has gone 
back, on the union of these cells, to that of the moncr. As if 
nature was not satisfied that any form of life should begin with the 
cell, the second stage of existence, but required absolutely that 
every being, no matter how high might be its destiny, should go 
to the very foot of the scale and climb the entire distance, in order 
that it might pass through every form that has belonged to its 
whole line of ancestors. 
From another point of view, this union and literal blending of 
the male and female principles is not only of the highest intellectual 
interest, but is calculated to awaken the most lively aesthetic senti- 
ments. Nothing more poetic or romantic has ever been presented 32 
GENESIS OF MAN. 
to the human fancy by all the fictions of the world than the mar- 
vellous reality of this courtship of cells! The very fountain-head 
of love (Urquelle der Licbe)\s reached in the affinities of two cells! 
The ruling passion of all ages has its ultimate basis in this new- 
found physiological fact. When the march of science shall have 
exposed the false basis upon which the present artificial code of 
social life rests, and when the fears of those who can imagine 
nothing better shall have been dispelled, then let the future Homer 
of science sing, not the illicit loves of Paris and Helen, which 
whelm great nations in untimely ruin, but the lawful wooings 
and the heroic sacrifices of the sperm- cell and the germ-cell as 
they rush into that embrace which annihilates both that a great 
and advancing race may not perish from the earth ! And here 
there is no fiction, there is not even speculation. Both the plot 
and details of this tale belong to the domain of established fact, 
and rest upon the most thorough scientific investigation. 
The structureless form first assumed by the fecundated ovum is 
termed a cytod, but from the circumstance of its being the onto- 
genetic form, which corresponds to the moner, Haeckel has also 
applied to it the systematic name of Monerula. In his system this 
is the stage of germ-development which the moner, before its 
further differentiation, had impressed upon all organic matter, 
and through which all higher forms must consequently invariably 
pass. 
This cytod or monerula stage is, however, of short duration. 
Very soon the homogeneous mass acquires a new nucleus, and 
thus again assumes the character of a simple cell. This second 
cell-form is so similar to that of the unfecundated ovum that many 
observers who had actually witnessed the cytod-form, on looking 
again, soon after, and seeing only the primary cell-form, had dis- 
credited their intermediate observations. It was not until the en- 
tire transformation had been repeatedly witnessed through all the 
steps of its progress, that the fact of such a strange transition be- 
came established beyond a doubt. 
The new cell, although indistinguishable from the old, possesses 
an invisible element derived from the absorbed substance of the 
sperm-cell which gives it the potential character of the parents. 
The old cell, as such, was an independent living organism, capa- 
ble of performing the essential functions of life, including that of GENESIS OF MAN. 
33 
reproducing its kind; i. e., of dividing up into cells like itself, but 
which could progress no farther. The new cell, on the other hand, 
is the germ of a highly-organized being. 
This is the seco7id, or ovulum-stage of development which has 
been impressed upon the germ by the amoeba stage of phyloge- 
netic development. The human being is now an amoeba. 
The next step in the development of the fecundated germ con- 
sists in a process of division which takes place in the nucleus. 
This first divides into two, and the surrounding protoplasm ar- 
ranges itself into two hemispheres so as to form a double cell. 
Then each of these two nuclei, with its surrounding protoplasm, 
goes through the same process, dividing the cell into four parts. 
The same process is then repeated for each of these parts, and so 
on, increasing the division in a geometrical progression, until the 
entire contents of the chorion consist of a mass of closely-aggregated 
minute cells. 
The form which the fecundated egg has now assumed, is called, 
from its resemblance to a mulberry, the Morula, and constitutes 
the third, or Monda-stage of development. It is merely a com- 
pound form of the simple cell. Instead of one comparatively 
large cell, it now consists of an aggregated society of small cells. 
Prof. Haeckel has established a theoretical group of compound 
amoebje, which he calls Synamoebia, as the phylogenetic ancestral 
form to which the Monda owes its existence; but it has been shown 
by the researches of Archer and Cienkowski into some species 
of Cystophrys and into the Labryinthidece, that these hypothetical 
Synamoebia have an actual representation in the fauna of the globe. 
These creatures are found to consist of formless accumulations of 
similar simple cells. 
The fourth stage of germinal development is the Blastosphaere- 
stage. It consists of a transformation of the Morula, which is 
brought about by the absorption of a clear fluid from the medium 
in which it is situated, which collects at the centre and crowds the 
cells outward, pressing them together until they are made to form 
a single layer upon the inner surface of the chorion, and thus leav- 
ing the whole interior filled only with the new liquid. The germ 
is enlarged during the process, from its former diameter of about 
one-tenth of a line to that of half a line. The cells now forming 
this single layer have assumed a hexagonal shape, due to their 34 
GENESIS OF MAN. 
lateral pressure against one another. The new form is denomi- 
nated the Blastosphaera or vesicula blastodermic a, while the cellular 
layer bears the name of germinal membrane (Keimhaut) or blasto- 
derm. 
The blastosphaere is a stage of embryonic development which is 
common to all creatures that have a higher organization than that 
of the synamoebian societies of cells. In many of the lower forms 
of life it becomes a stage of metamorphosis rather than of embry- 
onic development, these minute blastosphaeres lead independ- 
ent lives for a time, as the larvae of higher forms. This is the case 
with the calcareous sponges, with many zoophytes, worms, ascidi- 
ans and molluscs. Such larvae are called Planulce. They are 
usually covered with cilia, which serve as aids to locomotion. 
These facts alone would justify the believer in the dependence of 
ontogeny upon phylogeny in maintaining that this stage had once 
formed the highest plane of development, and that there had once 
existed a race of creatures which, after passing through the three 
preceding stages, completed their career as true blastosphaeres, and 
that all higher organisms must, in that sense, be descendants of 
such a race. Haeckel assumes such a group of creatures, which 
he calls the Planaeada. This hypothesis, however, was scarcely 
necessary, from the fact that there are animals well known to 
science which conform in their general structure entirely to this 
stage of development. Many such creatures now exist, both in 
the sea and in fresh water, consisting of a single exterior layer of 
cells, surrounding a fluid or gelatinous interior, and usually pro- 
vided, like the larval forms, with locomotive cilia. Especially may 
be mentioned the Synura in the Volvocinae and the Magosphaera 
planula. The latter was discovered and named by Haeckel, who 
has carefully traced its development through the lower stages, and 
proved the Planula to be its highest and mature condition. Such 
an animal is, therefore, a true Planaea, as strictly so as are the 
members of Haeckel’s theoretical ancestral group of Planaeada. 
To the philosophical embryologist, the blastosphaere-stage pre- 
sents an extraordinary interest. Nothing could illustrate this 
better than the remarkable utterance which it has elicited from Von 
Baer himself, one of the few of his statements which possess not 
only an ontogenetic, but also a phylogenetic significance. “ The 
farther we go back,” says he, “the greater agreement do we find, GENESIS OF MAN. 
35 
even in the most different animals. We are thus led to the ques- 
tion, whether at the commencement of development, all animals 
were not essentially alike, and whether there does not exist for all 
a common primordial form? As the germ is the undeveloped 
animal itself, so it may be reasonably stated that the simple blasto- 
-4 
sphaere (Blasenform) is the common fundamental form out of 
which all animals are, not only ideally, but historically devel- 
oped.” 
The next and fifth stage of embryonic development is the most 
important of all, as it leads us directly to the consideration of 
Haeckel’s celebrated “Gastraea Theory.” The ontogenetic form 
is called the Gastrula, which differs in two important respects from 
the Planula. Instead of a single cellular layer, as in the latter, 
the Gastrula possesses two such layers, one immediately within 
the other. These layers themselves differ from that of the Plan- 
ula, in consisting of several rows of cells instead of one, thus form- 
ing two distinct coats composed each of several layers of cells. 
These two coatings are quite independent of each other, and may 
be easily separated, which is not the case with the layers of cells 
composing each coat. The two coats differ still further from each 
other, in being made up of unlike cells. Those of the inner are 
larger, softer, and darker colored than those of the outer. 
The other important distinction between the Gastrula and the 
Planula is the possession by the former of an orifice at one point 
on its surface, through which it receives its nourishment, and 
excretes refuse materials. This form of the Gastnda-stage, how- 
ever, it should be stated, cannot be identified in the higher verte- 
brates. In man it is represented merely by a disc-shaped thicken- 
ing at one spot on the spherical germ, and the formation there of 
the two primary germinative layers which extend round into a sort 
of sack, which is the unmistakable homologue of the typical Gas- 
trula of the lower animals. 
The process by which the embryo passes from the Pla7iula to 
the Gastrula state, though simple, would be somewhat tedious, and 
the reader must be referred for the details of this transition to 
treatises on embryology, or to Prof. Haeckel’s own work. 
An extraordinary interest attaches to this stage ot ontogenetic 
development, in consequence of its carrying the embryo across the 
line which separates the Protozoa from the Metazoa. Haeckel in- 
sists upon this as the primary division of the animal kingdom. 36 
GENESIS OF MAN. 
The Protozoa are not a co-ordinate department or type with the 
Vertebrates, Mollusks, etc. They constitute a sub-kingdom, co- 
ordinate only with the other sub-kingdom of Metazoa, under which 
these types all fall. To class the Protozoa among the Radiates 
would be equivalent to placing the Cryptogams under the Endo- 
gens in a botanical system. The reasons for this are purely onto- 
genetic. The Gastrula possesses the two primary germinative 
layers, which belong to none of the forms below it. The most 
thorough embryological research has established beyond a doubt 
the important fact that all the tissues of the body of every animal 
that develops beyond that stage, are evolved out of the one or the 
other of these primary layers. The Protozoa and the Metazoa are 
therefore separated by the broadest possible line of demarkation, 
the former possessing no primary germinative layers, while the 
latter are either composed of them or developed out of them. 
The extreme importance of these cellular layers, therefore, be- 
comes at once apparent, and it is upon the manner in which the 
different tissues of the body are formed out of this simple building 
material that the most patient and indefatigable embryologists 
have been engaged during the past half century. It is found that 
from the outer layer or exoderm are formed : first, the epidermis 
and organs arising from it (hair, nails, feathers, scales, etc.); sec- 
ondly, the nervous system and the most important part of the 
organs of sense; thirdly, the greater part of the flesh of the body, 
the muscles; and fourthly, the skeleton of vertebrates; in short, 
all the organs of locomotion and sensation. 
Out of the inner layer, or entoderm, on the other hand, are de- 
veloped first, the inner lining or epithelium of the entire cavity 
of the body, together with that of all the glands and organs be- 
longing to it, lungs, liver, etc.; secondly, the muscles of the in- 
ternal vegetative system, including the heart; and thirdly, the cells 
of the generative organs. This last, however, is still open to some 
doubt. 
In consequence of these special functions performed by each of 
the two primary germinative layers, the outer one has been called 
the animal germ-layer {animates Kcimblati), and the inner the vegeta- 
tive germ-layer (vegetatives Keimblati). The Latin terms exodcrma, 
dermophyllum, lamina dermalis, and lamina serosa, have also been 
applied to the former, and entoderma, gastrophyllum, lamina gas- 
tralis, and lamina mucosa to the latter. GENESIS OF MAN. 
37 
The Gastrula is a common larval form of many lower animals, 
such as Sponges, Polyps, Corals, Medusae, Worms, Mollusks, and 
Radiates. It is also a larval form of the two most interesting of all 
animals for the history of development: viz., the Ascidian and the 
Amphioxus. Many Zoophytes and sponges are indeed nothing 
more in their final state than an aggregation or society of Gastru- 
lae. They therefore constitute a compound Gastraca. 
There is still another larval form belonging to this class which 
possesses an almost equal interest with the Gastrula. This is the 
Ascnla. It belongs to the life histories of both Sponges and Me- 
dusae, being developed out of the gastrula-form, and from it the 
fundamental biogenetic law leads us back to the long extinct Pro- 
tascus, or primordial sack, which was the ancient progenitor of 
the Zoophytes. It is fixed to the bottom of the sea, having its 
open end directed upward. No longer needing the cilia em- 
ployed by the Gastrula as organs of locomotion, these are conse- 
quently wanting. Its body consists of a simple sack or stomach, 
whose walls are formed by the two primary germinative layers in 
all their primordial simplicity. 
The already famous Gastraea Theory of Haeckel is nothing 
more than the simple application of his fundamental biogenetic 
law to the Gastrula stage of development. By this law he is led 
to the conclusion that at one period in the history of the globe, an 
animal, having at maturity the form and organization of the Gas- 
trula, and to which he gives the name of Gastraea, constituted the 
highest form of organic development upon it, and that from this 
primordial state of the two primary germinative layers, the process 
of differentiation of organs proceeded, until the present complex 
state of the animal kingdom has been reached, even as from the 
embryonic gastrula-form the highest of living beings are now de- 
veloped through this ontogenetic recapitulation. “ The Gastraea,” 
says he, “must have lived at least during the Laurentian period, 
and sported about in the sea by means of its ciliated exterior coat, 
in the same manner as the free-moving Gastrulae now do.” 
The great interest which attaches to the Gastraea Theory, as 
already remarked, arises out of the immense importance of the 
primary germ-layers as the basis of all future histological develop- 
ment. That which carries it further out into the field of specula- 
tion, however, and thus in one way adds still more to its interest, 38 
GENESIS OF MAN. 
is the difficulty both in finding the true homologue in man and 
the higher vertebrates generally, of the Gastrula of the Ascidian 
and Amphioxus, and also in finding any good systematic represen- 
tative of the ancestral Gastraea. 
The rest of the history of the ontogenetic development of man 
is the history of the differentiation of the two primary germina- 
tive layers. The Gastrula stage has furnished, in these two layers, 
the raw material for the entire future structure. By watching the 
progress of growth in exoderm and entoderm, the successive tis- 
sues of every part of the body may be traced to the highest degrees 
of specialization. From this point of view that stage possesses an 
interest far exceeding that of all those that have preceded it: for in 
it is found the first truly specialized organ. That organ is the sto- 
mach. The two essential functions of life are nutrition and repro- 
duction. The one is the promoter of ontogenetic, the other of 
phylogenetic development. But, as we saw in the cell, these two 
functions are originally one, and that one is nutrition. Repro- 
duction appears here as a mere continuation of nutrition. Nutrition 
goes on to the limit of growth, when division takes place. Nutri- 
tion is commuted into reproduction. Generation is phylogenetic 
nutrition ; a truth which we should never have reached except by 
the study of the lowest organisms. Nutrition, therefore is the one 
essential function of life. The organ of nutrition is the stomach. 
How significant, and yet how reasonable, that in the course of 
development the first specialized organ should be the stomach, and 
that the first creature possessing a specialized organ should consist 
wholly of a stomach! Such a form is the Gastrula ; such a crea- 
ture was the Protascus; and such is the hypothetical Gastraea of 
Haeckel. 
The sixth stage of the ontogenetic development gives the human 
embryo the form and organization of a worm. Our moral and 
religious teachers have from time immemorial delighted in remind- 
ing us that we were but “worms of the dust.” They should thank 
science for demonstrating that they were right. We might almost 
give them credit for an inspirational insight, did they not render 
their sincerity questionable by the indignation they evince when 
told that in the same sense that we are worms, we are also apes. 
The first important step in the progress of embryonic develop- 
ment, after leaving the Gastrula-stage, is the formation of two GENESIS OF MAN. 
39 
additional germ-layers out of the two original ones. The exact 
mode of their development is still under discussion among embry- 
ologists. Haeckel believes that the original exoderm and ento- 
derm secrete each a new layer of cells from its inner surface; that 
is, from the surface of each which is contiguous to the other, so 
that the two new layers lie against each other and separate the 
primary by the thickness of both. It is, nevertheless, considered 
that in the process the original constitution and identity of the 
primary layers are destroyed, so that they have virtually resolved 
themselves into four secondary germ-layers. The two outer layers, 
however, now perform together the office of the original exoderm, 
while the two inner ones take the place of the entoderm. This 
division into four secondary germinative layers is the final division, 
all the tissues, without exception, being formed out of these, as 
they have in nearly every case been traced. 
The names assigned by Von Baer and by Haeckel to these sec- 
ondary layers have reference to the functions which they are found 
to perform. Being all German in their etymology, they are diffi- 
cult to render into English. The following may answer as such 
an imperfect version:—Numbering them from the outside, the 
first is called by Von Baer the skin or dermal layer (Hautschicht), 
and by Haeckel the dermo-sensory leaf or fold (Hautssinncsblatt). 
The second is the muscular layer (Fleischschicht) of Von Baer, and 
the dermo-fibrous leaf or fold (Hautfascrblatt) of Haeckel. The 
third is Von Baer’s vascular layer (Gefdssschicht), and Haeckel’s gas- 
tro-fibrous leaf or fold (.Darmfaserblatt). The fourth, or extreme 
inner layer, Von Baer has denominated the mucous layer or mem- 
brane (Schleimschicht), while Haeckel calls it the gastro-glandular 
leaf or fold (Darmdr'iiscnblatt). Space will admit of no further 
following out of this interesting part of the history of embryonic 
development. 
All worms are composed of these four secondary germ-layers, 
the lowest possessing them in their greatest simplicity. The popu- 
lar idea of a worm is an elongated creature, consisting of many 
joints or rings [somites), but this is only a compound state of the 
primitive worm, each ring or joint constituting, zoologically, a dis- 
tinct individual, and possessing morphologically, if not physiologi- 
cally, all the characters of one. The primitive worm has but one 
joint. Among the lowest of the worms are the Turbellaria, which 40 
GENESIS OF MAN. 
in many respects resemble the Gastrulae of some higher animals. 
Like them, their body consists of a simple sack with only a single 
orifice, and even possesses the ciliary organs of locomotion. The 
great difference lies in the nature of the cellular layers composing 
this sack. In the Eirbellaria these-are the four secondary instead 
of the two primary germinative layers. Haeckel reasons here to 
an ancient primordial worm (Urwurm, Prothelmis), corresponding, 
in all respects, with this stage of embryonic development in man 
and the higher animals generally, and from which not only all 
other worms, but all creatures higher than the worms, including 
mankind, have descended. This worm-stage acquires an increased 
interest from the circumstance that here the main trunk divides, 
sending off the articulate branch in one direction and the mollusk 
branch in another, leaving only the vertebrate stem. The embryo 
assumes a certain bilateralness, the four secondary germinative 
layers grow together at their dorsal median line, and a chorda 
dorsalis is formed. This is the true Chordonium-stage. The em- 
bryo now has the closest affinities with the larval state of the As- 
cidian, which, strangely enough, though wholly devoid of a chorda 
in its final state, has a well-defined one in its larval state. There is 
another creature, the Appendicularia, which possesses a chorda 
dorsalis throughout its existence, although in all other respects it 
is a true worm, and belongs, with the ascidians, to the Tnnicata. 
This animal is the true connecting link between the worms and 
the vertebrates, between the ascidian and the amphioxus. The 
hypothetical Chordonium of Haeckel, the assumed ancestor of the 
human race at this stage, and exact representative of the embryo 
at this period growth, differs scarcely at all from the Appen- 
dicularia. It is the common ancestor of the Tunicata and the 
Vcrtcbrata. 
From a worm, the embryo passes directly into a vertebrate. As 
the ascidian larvae, the appendicularia, and the amphioxus are 
separated only by the smallest differences, although the two former 
are clearly worms, while the latter is clearly a vertebrate, so the 
corresponding transition stages in the embryo are distinguished 
only by almost imperceptible shades. 
The future man is now a vertebrate, but without distinct ver- 
tebrae. He is wholly without brain or cranial enlargement, with- 
out a regular heart, without mouth, without limbs. He now be- GENESIS OF MAN. 
longs to a great subtype of the Vcrtebrata, which Haeckel denomi- 
nates the Acrania. This entire sub-type has now but a single 
known living representative on the globe, the amphioxus9; but 
Haeckel believes that a period existed when the Acrania greatly 
prevailed over the Craniota, or cranium-bearing vertebrates, and 
peopled all the seas and waters. This Acrania or amphioxus form 
constitutes the seventh stage of ontogenetic development. 
The next or eighth stage is the Lamprey or Monorrhina stage. 
The nervous system and the vertebral column begin to differen- 
tiate. The spinal marrow undergoes a slight enlargement at its 
anterior extremity, which is the rudiment of the brain. The 
vertebral column begins to develop out of the rudimentary 
chorda dorsalis. This does not take place by a gradual, simulta- 
neous formation of all the vertebrai along the line of the chorda, 
but, singular as it may seem, by the formation of one vertebra 
after another, beginning with the most anterior. This remarkable 
process points unmistakably to the composite character of the 
frame-work of every vertebrate body. Each vertebra of a verte- 
brate, like each ring of an annelid, represents a distinct and once 
independent unit of a compound organism. 
The present Cyclostomata or Mopiorrhinae are believed by Haeckel 
to be the sparse remains of a once great group of animals, which in 
ancient times shared the possession of the globe with their gradually 
increasing rivals, the Amphirrhinae, which had sprung from them 
just as the embryo of every higher vertebrate passes from the con- 
dition of the one into that of the other. The type of the former is 
the still living Lamprey or letromyzon. As the names imply, the 
Monorrhinae have but one orifice for mouth and nose, which is of 
a circular shape, and is used as a sucker, while the Amphirrhinae 
are provided with a pair of jaws and two nasal orifices. Excluding 
the Amphioxus [Acrania) the entire vertebrate type (Craniota) falls 
under these two groups, the Amphirrhinae embracing all the higher 
vertebrates, from the lower fishes upward. 
From the form of the first of these groups to that of the second 
the embryo now passes, and enters upon its ninth stage of develop- 
ment; it becomes a fish. But as natura non facit saltum, this first 
9 A second acranial animal, discovered near I’eale Island, Morton Bay, Australia, 
has very recently been reported to the Royal Society by Prof. W. Peters, who has de- 
scribed it under the name of Efiigomet/iys cultellus. This discovery is of the highest 
interest'to naturalists. 42 
GENESIS OF MAN. 
fish-form is not that of a true Tcleost, or ordinary bony fish, but of 
a Selachian. Indeed, the higher fish-form is never attained, but the 
embryo skims along at the bases of the great ichthyic and amphi- 
bian branches, without becoming at anytime a true fish or a true 
Batrachian. This is a very significant fact, and one which, while it 
is easily accounted for by the general theory of descent, forms at 
the same time a powerful ontogenetic argument for the truth of 
that theory. For the typical representatives of any great group 
exhibit only the extremities of greatly differentiated branches remote 
from the parent stem, and it is not to be expected that in the 
corresponding embryonic forms of animals higher up the stem we 
should see anything but copies of those forms which existed prior 
to, or at the commencement of, ramification, and which are conse- 
quently within the common line of descent of both. 
Some will, perhaps, regret that their ancestors should have been 
worms, while they cannot count in their pedigree either the bee or 
the ant; others may not feel flattered to be informed of their close 
relationship with the frog and the toad; but few, I think, will be 
sorry to learn that their forefathers were not reptiles, though this 
fact precludes the more pleasant thought of claiming relationship 
with the birds; for birds, with all their grace, beauty, and inno- 
cence, are neither more nor less than transformed reptiles. 
The human embryo passes along the base of the Batrachian 
branch and through the Sozura (thus saving its tail) and so keeps 
quite aloof from the wfiole race of lizards, snakes, turtles, etc., and 
a fortiori, of birds. The unborn man is first a Selachian, then a 
Lepidosiren, then a Siren, and finally a Triton. His first limbs are 
fins, his first respiratory organs are gills, and his lungs are at first 
fish-bladders. 
The tenth and last stage of ontogenetic progress is denominated 
by Haeckel the Amnion-stage. This stage embraces not only that 
of all true mammalian forms, but also takes in the two inter- 
esting antecedent groups, the Monotrcmata and the Marsupialia. 
Haeckel establishes a hypothetical Protamnion, which he locates 
in the Permian period, and which he claims to have been the 
original progenitor of all the Amniota, or amnion-bearing animals. 
The distinguishing characteristic of this embryonic form, as the 
name implies, is the beginning of the development of the impor- 
tant organ known as the amnion, which is simply a large extension 
of the yolk-sack, and is filled with a nourishing fluid. This fluid GENESIS OF MAN. 
43 
is gradually absorbed and appropriated by the embryo, and fur- 
nishes a portion of its nutrition. Simultaneously with the amnion 
is developed also another important organ, the Allantois, or pri- 
mordial urinary sack. Both these organs are confined to the three 
highest classes of Vertebrates (reptiles, birds and mammals). The 
embryo now begins to manifest decided mammalian characteristics. 
Already, the gills have disappeared, having become transformed 
into jaws, hyoid bones, and otolithes: the heart has acquired its 
four chambers, and the swim-bladders have been specialized into 
lungs. For a while the uro-genital and excrementary orifices 
empty into the common cloaca giving it the monotreme character. 
Then, while the •allantois is still present, a partition separates 
these, making both open externally. This is the Marsupial stage. 
Lastly, the allantois is transformed into a placenta, and the pure 
mammalian stage is reached. Leaving the great branches of the 
Carnivora and Rodentia on the one hand, and of the Ungulata and 
Cetacea on the other, the embryo now passes through the various 
phases of a Sloth-form, an Ape-form, and an Anthropoid-form ; 
and, conditions being normal, emerges on the two hundred and 
eightieth day of gestation with the form of a human being. 
No one who experiences the least regard for natural truth, what- 
ever views he may hold respecting the meaning of particular facts, 
can contemplate so remarkable a series of phenomena as this, and 
realize that he has himself once been the subject of such a strange 
course of development, without being led into a train of reflection 
which will open up to his mind broader and juster conceptions of 
the universe. 
At the same time it would be impossible to exaggerate the 
degree of added strength which a popular acquaintance with the 
bare lacts of ontogenesis would impart to the hypothesis of devel- 
opment or modern doctrine of descent, and thus indirectly to the 
general conception of the law of universal evolution. 
111. 
PHYLOGENESIS. 
THE fundamental biogenetic law that ontogenesis is an abridged 
repetition of phylogenesis, that the transformations through 
which the individual passes during its ante-natal and post-natal ex- 
istence in the brief period of its career, are a mere reflection of those 44 
GENESIS OF MAN. 
through which its race has passed during the long ages of its slow 
development, and that the latter process is the strict physical and 
mechanical cause of the former,—this deepest of all biological laws 
Haeckel no longer treats as a theorem requiring demonstration, but 
employs it as a postulate by the aid of which all the most trouble- 
some gaps left in the anthropogenetic series by the evidences of 
comparative anatomy, paleontology, and geographical distribution 
(chorology), are satisfactorily closed. Such gaps have existed along 
the entire line, rendering it difficult and in many cases impossible 
to trace it, and leaving so large a part of the whole theory of de- 
scent a matter of conjecture, that it was easy for those so disposed 
to point out unanswerable objections. But once admit the facts of 
ontogenesis, and miracle alone, and this of the most incredible kind, 
is the only alternative to the acceptance of the fundamental law, 
which, candidly viewed in the light of these facts, bears every mark 
of inherent probability. Not only does this law fill out numerous 
voids and supply many wholly “ missing links” in the phylogenetic 
chain, but it also confirms, in the most remarkable manner, nearly 
every item of the evidence furnished by the other sources of proof 
of the doctrine of descent. . 
Great, indeed, was the step which this doctrine took when the 
remarkable revelation was made in the domain of comparative an- 
atomy, that the Amphioxus possessed a chorda dorsalis, and that 
the Ascidian larva contained an even more distinct trace or rudi- 
ment of a vertebral column. Professional naturalists, without pre- 
conceived ideas could no longer resist the inference that here was 
the true nexus between the worms and the vertebrates. Consider 
now, the almost crucial verification which this hypothesis received 
when it was found that the embryonic stages of every creature 
higher in the scale of being than the Amphioxus presents phases 
identical with those of that animal and of the Ascidiae, that even 
the human embryo has its worm-stage immediately succeeded by 
its Chordonium stage, and this again by its Acranial stage ; the 
collateral proofs extending even to the germinative layers, and thus 
rendering the correspondence complete and the inference irresist- 
ible. Equally pointed illustrations might be drawn from many 
other points along the line of common descent. 
But valuable as is this class of evidence at these comparatively 
advanced stages, it is still more so far down toward the dawn of GENESIS OF MAN. 
45 
organic existence. For while in the former it only serves to 
supply the omissions or verify the testimony of an array of pa- 
leontological, anatomical, and chorological facts, in the latter it 
stands alone as the sole evidence of a tangible character of the 
development of living forms out of the primordial and unorganized 
plasma of nature, and indeed from inorganic matter itself. These 
ontogenetic stages have already been considered, and unavoidable 
mention made of many of the forms to which they correspond, and 
whose stamp they bear. 
The deeper problem of the origin of life on the globe is one 
which strictly belongs to phylogeny, and one which Haeckel has 
not hesitated squarely and boldly to meet. The doctrine of spon- 
taneous generation, or archigonia, is by no means so simple as 
many suppose, and is not to be settled either by the success or 
failure to originate bacteria, diatoms, and monads, under certain 
conditions, in organic infusions. 
The only form of generation which has ever yet come within 
the scope of human observation, and which, from the nature of 
things, can ever be expected to be directly witnessed by human 
eyes, is, of course, that wherein the offspring proceeds directly 
from a known and distinct parentage. This form of generation is 
called tocogonia, and genesis itself in its widest sense is, therefore, 
primarily divided into archigonia and tocogonia. 
The exceedingly complicated subdivision of tocogonia must be 
passed over, as we need consider here only the simpler but still 
somewhat complex one of archigonia, or original spontaneous 
generation. Although nothing is perhaps empirically known re- 
specting this process, its existence as forming the first link in the 
phylogenetic chain, possesses the highest degree of probability a 
priori, which is not at all lessened by any empirical failures to sub- 
ject it to the testimony of the senses. 
The problem divides itself into two, which Haeckel considers 
distinct and independent. The phenomenon assumed by the one 
he calls plasmogonia, in which the genetic process is conceived as 
taking place in a fluid containing organic matter, which is supposed 
by some to be essential to the origination of life. The other form 
of archigonia, on the other hand, conceives the process as taking 
place in a medium consisting wholly of inorganic elements, and 
Haeckel accordingly denominates this process autogonia, i. e., un- 46 
GENESIS OF MAN. 
aided self-generation. It will be observed that the great majority 
of the experiments thus far tried, have been confined to the first 
of these classes, or plasmogonia. If we now consider the second 
class, or autogonia, we perceive that this also presents a two-fold 
problem. It is either a process which, under certain rare and 
favorable conditions, is going on at all times in some parts of Na- 
ture’s domains, or it may be one which was only capable of taking 
place at one period in the geological history of the globe, when 
conditions existed which were quite different from those now 
existing, and that all the life now found on the globe has descended 
through the tocogonic process from the primordial organisms then 
created. 
To all these questions but one answer can be given; but this is 
an answer which either must be given, or else the whole monistic 
theory must be surrendered. The answer is that somewhere and 
at some time the organic world must have developed out of the 
inorganic. 
This is all we really know, but this we do know just as well as 
we know that the surface of the earth has undergone the changes 
which geology teaches that it has undergone. One of three things 
is certain : either organic life must have existed from eternity, or 
it must have been created specially, or it must have had a natural 
origin out of inorganic matter. The first of these contradicts all 
the facts of geology and all our modern ideas of the cosmogony of 
our system. The choice lies, therefore, between the other two, 
and for the consistent dysteleologist there remains no alternative. 
Haeckel, however, is undoubtedly too hasty in many of his 
sweeping assumptions respecting this problem, as for example, 
that of the direct autogonia of his moners, such as Bathybius 
Haeckelii of Huxley, who dredged it from the bottom of the 
Atlantic, where it exists in vast quantities as a strange, unorganized 
mass of living protoplasm. Even this would doubtless be too 
great a saltus for Nature to make. It is certainly far more in har- 
mony with Nature’s processes generally, and with the whole tenor 
of the monistic or genetic philosophy, to conceive that between 
the two divisions of archigonia which he establishes, autogonia and 
plasmogonia, there is in Nature a regular gradation, as throughout 
the rest of her domain, and that she first develops the plasma, that 
is, some combination of organic matter, consisting of the necessary GENESIS OF MAN. 
47 
nitrogenized and carbon compounds in a high state of complexity 
and instability, and then, as a mere continuation of a uniform pro- 
cess, impresses this, first with the lowest and then with higher and 
still higher vital properties. For life is unquestionably a product 
of molecular organization. 
While, therefore, inorganic matter must be regarded as the 
primordial ancestor of all organized beings, the first stage in the 
genealogical development of all living things, and hence also of 
man, must have been some form of moner. Haeckel enumerates 
eight genera of moners now existing on the globe, and there can 
be no doubt that there are many more still undiscovered, and their 
extreme and absolutely structureless simplicity renders it highly 
probable that they are really the first form of life which was 
developed on the globe. 
The direct descendants of the moners are undoubtedly the 
various forms of amoeba. About the only observable differentia- 
tion required to effect this transformation, is the development of a 
nucleus in the interior of the protoplasmic substance of the former 
creature. This change converts the cytod into a true cell, and such 
is the character of the amoeba, a simple individual of the first 
order. According to Haeckel, neither the moner nor the amoeba 
can be strictly classed either with animals or with plants. They 
belong, together with many other lowly-organized beings, such as 
the Flagcllata or lash-cells, the diatoms and the rhizopods, to his 
famous third kingdom the Protista. As moners, however, are the 
lowest of all forms of life, he divides these into three classes, 
animal moners, vegetable moners, and neutral moners. The first 
class develop into the lowest animal form, the Protozoa ; the sec- 
ond into the lowest vegetable form, the Protophyta ; and the third 
into the neutral form, the Protista. He also speaks of animal 
amoebae, and seems to regard these creatures more nearly allied to 
animals than to plants. At least, he places both the moner and 
the amoebae at the base of the animal scale, as the first and second 
terms of the phylogenetic series. 
From the amoeba-group proceed the true Protozoa, which, 
therefore, stand in the anthropogenetic line. Applying now the 
biogenetic law to the Monda-stage of ontogenesis, we are able 
to conclude that these animal amoebas, at one period in their his- 
tory of development, formed societies or compound individuals 48 
GENESIS OF MAN. 
(.Synamoebia), which therefore constituted the corresponding third 
stage of development in the anthropogenetic line. 
There must have next existed, as the fourth stage, a family of 
creatures standing at the base of the protozoa, whose bodies con- 
sisted of a simple, hollow sphere, the walls of which were formed 
of a single layer of cells. These were the Planaeada, and they 
find their embryonic recapitulation in the blastosphaere stage. 
These creatures are not yet so far extinct but that representatives 
of them still exist in Haeckel’s Mogosphacra, in Synura, and in 
other marine and fresh-water forms. 
The gastrula-form of embryonic development, barely traceable 
in the higher vertebrates, but common to both Amphioxus and 
Ascidiae, as well as to many lower forms, is all there is to warrant 
the assumption of a class of beings once peopling the waters of the 
globe, whose bodies consisted of a simple sack, open at one end, 
and formed of two cellular layers. These were the interesting 
Gastracada, which have given to all the forms that have descended 
from them the warp and woof of all their tissues, the primary ger- 
minative layers. They must have developed directly out of the 
Planaeada, and form the fifth stage in the descent of man. 
Ontogenesis next points, as a sixth stage, to an extinct race of 
primordial worms, Archelminthes, which originated from the Gas- 
traeada by the formation of an intermediary germinative layer, 
from which the two inner secondary layers eventually differen- 
tiated. These creatures belonged to the lowest sub-division of the 
worms, the Acoclomi, which, as their name implies, possess no cav- 
ity of the body (coelom) distinct from the sack-like stomach. They 
are also without any vascular system, heart, or blood, but manifest 
the first traces of the formation of a nervous system, the simplest 
organs of sense, and rudiments of secretive and reproductive 
organs. The typical representatives of the Archelminthes are the 
Turbellaria, but they also closely resembled the parasitic Trema- 
toda and Cestoda, which belong to the group Acoclomi. Thus is 
man connected by blood relationship with the loathsome tape- 
worm that infests his stomach ! 
Out of the Acoclomi were developed the Coelomati, which, still 
low in the scale, nevertheless possess a distinct coelom. The now 
extinct race which effected this transition have been called the 
Scolccida, and form the seventh stage of anthropogenetic develop- GENESIS OF MAN. 
49 
ment. The precise interval which they seem to have bridged over 
lay between the Turbellaria and the Enteropneusta, the last of 
which are represented by the well-known Balanoglossus. From 
this point the great articulate branch swung off, and a little higher 
the important branch of the Mollusks. 
To arrive at the eighth stage, we are again compelled to resort 
to the fundamental biogenetic law, and reason from the chordonium 
stage of embryonic development of all vertebrates to an extinct 
form, which must have possessed the rudiment of a vertebral col- 
umn in the form of a chorda dorsalis as a permanent character of 
its adult state. It would have been wholly impossible to say 
whether this assumed creature should be placed in the department 
of articulates, mollusks or worms, were it not for the flood of light 
which the anatomy of the Amphioxus and the Ascidian has, 
within the past few years, shed upon the whole problem. 
The existence of such a chorda in the former of these animals, 
and its presence also in the larval forms of the latter, are two facts 
which point unmistakably to the type Vermes as the one which 
has furnished the transition to the Vertebrata. No creatures have 
been found in any of the other types which afford the least intima- 
tion of any such transition, and neither in the Protozoa, the Zoo- 
phytes, the Echinodermata, the Crustacea, the Arthropoda, nor the 
Mollusca, has any trace of a chorda dorsalis, either in the larval or 
adult state, been detected after the most thorough examination. 
The conclusion is, therefore, irresistible, that the sub-kingdom 
Vermes and the class Tunicata have furnished the true progenitor 
of the vertebrates. This transition form itself has probably long 
been extinct, but it has left lineal representatives in the Ascidia, 
Phallusia, etc., which, while through long adaptation to a fixed 
existence during their adult state they have lost their chorda, still 
retain that distinctive character during their free larval state, as the 
unquestionable ontogenetic representative of an organ which they 
have inherited from their extinct chorda-bearing ancestor. This 
ancient and primordial ancestor of the vertebrate sub-kingdom to 
which so many facts, both of ontogenesis and of phylogenesis, with 
so great certainty point, Haeckel denominates the Chordonium. As 
if to put the solution of this important question beyond the possi- 
bility of a future doubt, it is now found that a member of this same 
group, the Appendicularia, actually preserves its chorda during life, 50 
GENESIS OF MAN. 
and this creature may therefore be regarded as a living representa- 
tive of the true Chordonium. 
The Amphioxus forms the ninth stage in the anthropogenetic 
line, and furnishes the first link in the vertebrate chain. It is the 
only known representative of the once great subdivision of verte- 
brates called by Haeckel the Acrania, or skulless vertebrates.10 Of 
this wholly unique and extremely interesting creature sufficient 
mention has already been made. 
The tenth stage is that of the Monorhina, or Cyclostoma, which 
have for their best-known representative the Petromyzon or lamprey. 
These arose out of the Acrania through a simple enlargement of 
the anterior extremity of the spinal nerve and the differentiation of 
the corresponding part of the chorda dorsalis into a rudimentary 
cranium. The distinctive circular mouth-orifice Haeckel regards 
as a mere adaptive character not present in the original progenitor 
of the Craniota. 
The transition to the eleventh, the Selachian or primordial fish- 
stage, took place through the formation of a pair of nostrils and a 
pair of jaws out of the simple, circular mouth-orifice of the Cyclos- 
toma. This transformation led to the Amphirhina, a branch of 
the Craniota, systematically coordinate with the Monorhina, but 
embracing all the rest of the vertebrate sub-kingdom. With the 
higher fishes (Ganoides and Teleostei) human genealogy is not 
immediately concerned, but only with the lowest sub-class, the 
Selachii, whose present living representatives are few, and comprise 
the sharks, rays, etc., but which formed, in the Devonian age, the 
chief population of the waters of the globe, as their singular 
heterocercal remains, found in the rocks of that period, abundantly 
attest. 
The transition from the Selachians was next to the Dipncusta, 
which constitute the twelfth stage. It was brought about by the 
natural adaptation of the organs of the body to a partially terres- 
trial existence. The swim-bladders were transformed into imper- 
fect lungs, the nasal orifices, which in fishes have no communication 
with the interior of the mouth, established such a communication, 
and the single auricle of the heart divided into two, thus corre- 
spondingly improving the circulation of the blood. Th& Dipneusta 
10 See note 9, page 41. GENESIS OF MAN. 
therefore employed their gills, which they retained, when in the 
water, but breathed through their lungs when on land. They form, 
therefore, a very anomalous and interesting transition group, con- 
necting the lowest fishes with the lowest amphibians. They were 
a very large class in paleolithic time, as their dental remains tes- 
tify, but at present only three genera are known, each with a single 
species, viz :—Protopterus anncctens, of the rivers of Africa; Lepi- 
dosiren paradoxa, of tropical America; and Ceratodns Forsteri, from 
South Australian swamps. 
Gegenbaur has demonstrated that the real character of the fins 
of fishes is that of many-toed feet. The changes that led from the 
fish to the Dipneusta seem not to have affected the number of these 
toes, although a certain adaptation of the fins to terrestial locomo- 
tion was perceptible. The next important transformation was to 
concern this part of the animal anatomy. The animals nearest 
related to the Dipneusta are unquestionably the amphibians, with 
which the former are frequently classed; but they differ from them 
in the important respect of possessing regular, five-toed feet. But 
one conclusion can be drawn from this fact, and this is that among 
the many and varied forms of the once great Dipneusta class, there 
was one whose locomotive organs had become transformed through 
adaptation and natural selection into five-toed feet, and that from 
this long extinct five-toed progenitor, the present amphibians have 
descended. The human embryo itself, and that of all the higher 
vertebrates, pass through an analogous transition. 
With frogs, toads, and other higher amphibians, as we are most 
familiar with them, the anthropogenetic line has no direct connec- 
tion. It constantly hugs the base of the whole group, exhibiting 
direct relationships only with the Sozobranchia, which, therefore, 
form the thirteenth, and the Sozura, which form the fourteenth 
stage. 
The former of these sub-classes comprises the Proteus, the Siren, 
and the Siredon, as among its best-known representatives, while to 
the latter belong the Triton and the Salamander. These once 
abundant but now comparatively rare creatures have furnished 
naturalists with some of the most interesting examples of what 
may almost be called the visible transmutation of species. It is 
well known that frogs and toads (Anura), the more highly differ- 
entiated amphibians, instead of possessing both lungs and gills GENESIS OF MAN. 
52 
during life, as do the Dipneusta, undergo a complete metamor- 
phosis after birth, passing from a true fish-form, in the tadpole 
state (in which, in addition to the well-known external fish-like 
cha’racters, they also possess gills and no lungs and a correspond- 
ing piscine circulation) to the familiar batrachian form, in which 
their respiration is through lungs only and their circulation through 
two auricles. Now, the two sub-classes above named furnish the 
most perfect and characteristic transition stages between the larval 
and adult stages of the higher amphibians. The Sozobranchia, as 
the term implies, preserve their gills through life, but also acquire 
lungs, and are therefore strictly amphibious. They live, however, 
chiefly in the water, and there perform all the functions of their 
existence. The greatest excitement in scientific circles has been 
recently called forth by the extraordinary conduct of a member of 
this group. The Mexican Axolotl (Siredon pisciforme) was observed 
in the Paris Jardin des Plantes, where large numbers of these 
creatures were kept, to frequently take to the land, and several 
individuals so far habituated themselves to terrestial life that they 
actually lost their gills in the manner of the higher amphibians. 
Individuals thus behaving were scarcely distinguishable from the 
Amblystoma, a genus of the Sozura which acquire lungs. 
An equally remarkable phenomenon, but of exactly the opposite 
class, was manifested by the Triton, which belongs to the last 
named sub-class, and therefore habitually undergoes the metamor- 
phosis common to frogs, etc., only without the loss of the tail. 
Before it arrives at maturity, the Triton, under ordinary circum- 
stances, loses its gills and leads a sub-terrestrial life, breathing 
only air. But by placing it in a tank so shaped that it was unable 
to get out of the water, it was thus compelled to retain its gills 
through life, and even propagated in the water. 
All animals above the amphibians are characterized by the pos- 
session, during their embryonic stages, of the important organ called 
the amnion, which is wanting in all below them, and in the amphib- 
ians themselves. The facts of ontogenesis, as well* as those of com- 
parative anatomy, justify the assumption of the former existence, 
probably in the beginning of the Mesozoic age, of a lizard-like 
animal whose fossil remains have not yet been discovered, and 
whose affinities with any known living form are not close, but 
which must have been the first to develop this particular organ, GENESIS OF MAN. 
53 
and was thus the progenitor of all that now possess it, and hence 
of man himself. This creature, which forms the fifteenth stage of 
man’s genealogy, Haeckel calls the Protamnion. Out of it was 
developed primarily the great reptilian class, from which proceeded 
later the birds, with neither of which has man any direct connec- 
tion. The origin of the mammals, however, must also be sought 
in the Protamnion stock, from which this class, too, must have pro- 
ceeded,—perhaps simultaneously with the reptilian branch, though 
in quite a different direction. The skull of all reptiles and birds 
is articulated to the atlas by means of a single condyle, while in 
mammals this condyle is double. From this circumstance the 
reptiles and birds have been designated by the common term 
Monocondylia. In them, also, the lower jaw is composed of several 
pieces, and movably joined with the skull by a special process, 
while in the mammals it consists only of a pair of pieces, and is 
immediately connected with the temporal bone. The further dis- 
tinction between the scales and feathers of the former and the 
hairs of the latter, is likewise an important one. The complete 
diaphragm of mammals, dividing the thoracic entirely from the 
abdominal viscera, and which is only partial in the Monocondylia, 
is a further very characteristic distinction. Finally, the existence 
of mammary glands in the latter, from which the class takes its 
name, and which are wanting in all other creatures, not only indi- 
cates a very distinct position for the mammals, but combines with 
other characters to place them at the head of the animal series. 
A very distinct race, which Haeckel styles the Promammalia, 
forming the next or sixteenth stage of man’s descent, must have 
developed out of the Protamnia, and transmitted all these marked 
peculiarities to the entire mammalian class. Man himself possesses 
all these special mammalian characteristics, and is therefore a 
genuine mammal. 
The nearest known living representative of these hypothetical 
Promammalia are the curious and remarkable Monotremata of 
Australia and Tasmania. Of the entire sub-class only three forms 
are known, the singular Orinthorhynchus paradoxus and the 
Echidna, of which there are two species, E. hystrix and E. setosa. 
These animals seem, at first sight, to form an immediate connecting 
link between the birds and the mammals, as they possess the beak 
of the former with the lacteal glands of the latter. They further GENESIS OE MAN. 
54 
agree with the birds in having the anterior extremities of the 
clavicles united to the sternum, forming a sort of merrythought. 
A still more fundamental point of resemblance to the birds, and 
that from which the sub-class takes its name, is the possession of 
a common cloaca, the urino-genital duct opening within the body. 
The monotremes, however, agree with the mammals in all the 
characteristic attributes above enumerated, such as double occipital 
condyle, complete diaphragm, etc., while the cloaca, the merry- 
thought, and other apparently avian characters, may have been 
inherited as well from the amphibians as from the birds. The 
beak, however, can only be accounted for as having developed 
independently from adaptation to conditions of existence similar to 
those which evolved the toothless jaws of turtles, from which it is 
believed the beak of birds has been derived. The beak of the 
Echidna differs from that of the Ornithorhynchus, and exhibits an 
approach towards the snout of the ant-eaters. The beaks of 
monotremes and of birds must therefore be regarded as simply 
analogous, and not as homologous organs. 
The Promammalia no doubt differed in many respects from the 
Monotremata, and Haeckel is inclined to believe that they pos- 
sessed regular teeth, which the latter lost through adaptive modifi- 
cation. At least, the earliest fossil remains that paleontologists 
have been able to refer with certainty to the mammals, and which 
occur in the triassic formation, consist of teeth only. From a few 
small molar teeth found in Germany, and also in England, Micro- 
lestcs antiquus has been constructed; and from similar dental 
remains found in this country, Dromathcrinm sylvestre has been 
described. 
Although the Monotremata differ from the Monocondylia (rep- 
tiles and birds) in so many important respects in which they agree 
with the higher mammals, they, nevertheless, also present many 
points of difference with these latter. In addition to those already 
mentioned (cloaca, united claviculae, etc.), the absence in these 
animals of any teats upon the mammary glands is very peculiar 
and anomalous. In consequence of this omission, the only way 
in which the young are able to obtain their nourishment, is by a 
process of licking against the porous breast of the mother; and 
Haeckel, therefore, proposes as a synonym for the ordinary name 
of the sub-class, that of Arnasta,—or mammals without teats. GENESIS OF MAN. 
55 
Again, the allantois is never transformed into a placenta, the corpus 
callosum is not developed, and there exists a pair of rudimentary- 
marsupial bones. This last character affords almost conclusive 
proof of the descent of the marsupials from the monotremes. 
The Marsupialia must therefore be regarded as the next group 
of animals in the regular line of descent which terminates in man, 
and as forming the seventeenth stage in the > development of the 
human race. Here the cloaca is divided by a horizontal partition 
into two distinct orifices, both opening externally; nipples are 
formed on the mammae, to which the young attach themselves, 
and the clavicles are distinct from the sternum. In these respects, 
the marsupials agree with all the higher mammals. The distin- 
guishing character in which they differ from them, and that from 
which the name of the sub-class has been taken, is the existence 
of a remarkable pouch or sack (marsupium) on the under side of 
the female, in which the young are placed at a very early period, 
and there retained until they are able to take care of themselves. 
This pouch has been aptly likened to a second or supplementary 
uterus, and the marsupials have accordingly been called by some 
Didelphia. Our well-known opossum (Didelphys opossum) is our 
only North American representative; but in Australia, this group 
of animals constitutes the greater part of the mammalian fauna. 
The absence of a placenta is the only other important particular 
in which the marsupials differ from the higher mammals. Indeed, 
the marsupium seems to constitute a sort of substitute for a pla- 
centa, and the want of the latter may be regarded as the physio- 
logical cause of the development of the former. The monotremes, 
however, are without either, and those who know would do well to 
explain how these animals are able to dispense writh them both. 
The so-called true Mammalia all possess a fully developed pla- 
centa, and are therefore distinguished from the two groups last 
mentioned as forming a third sub-class, the Placeyitalia. This 
organ is of great importance in the classification of the higher 
mammals, its mode of attachment furnishing excellent and reliable 
general characters. In some, for example, the placenta is decidu- 
ous from the inner wall of the uterus, while in others it is not, and 
on this distinction is based the primary division of the whole sub- 
class into the Deciduata and the Indecidua. The latter are the 
least perfectly organized, and comprise the Edentata, the Cetacea, 56 
GENESIS OF MAN. 
and the Ungulata. In man the placenta is deciduous, and he can 
therefore have descended from none of these. 
The Dcciduata again fall into two divisions according as the 
embryo is attached by the placenta to the uterus upon a single 
small area or disk, or by a band or girdle extending entirely 
around it. The former are called Discoplacentalia, the latter Zono- 
placentalia. The Zonoplacentalia embrace the Carnaria (Carnivora 
and Pinnipedia) and the Chelophora, to which the elephant belongs. 
The Discoplacentalia comprise the rodents, the Insectivora (moles, 
etc.), the Chiroptera (bats), the lemurs (Prosimiac), and the apes 
(Simiae). To this last legion, also, belongs man, who differs in 
this respect not at all from the mouse, mole, bat, lemur, of ape. 
Now it is a remarkable fact that in one order of the marsupials, 
the Pedimana, embracing the two families Chironectida and Didcl- 
phyida, to the last of which our opossum belongs, the hind feet are 
modified, in a peculiar way, into organs for grasping, resembling 
hands. This group can therefore only be regarded as exhibiting 
the earliest marks of that important course of transformation 
which culminated in the apes and in man. The course of develop- 
ment was from this group of marsupials directly to one within the 
Dcciduata. Leaving all other animals wholly out of its course, the 
line of descent of man passes immediately from the Marsupialia to 
the Prosimiac or lemur group, an order which Haeckel takes out 
of Blumenbach’s Qnadrumana, because it is so much farther sepa- 
rated from the other apes than any of these are from one another. 
They are ape-like creatures, but shade off in a very interesting 
way into nearly all the remaining orders of the Discoplacentalia. 
The Chiromys Madagascariensis forms the transition to the rodents; 
the Galeopithecus of the Sunda Islands, to the bats; the Macrotarsi, 
to the insectivora; and the Brachytarsi, particularly the Lori 
(,Stenops), to the true apes. They also exhibit close affinities to 
the Sloths (Bradipoda), which have been regarded as an order of 
the Edentata in the Indecidua; but recent investigations have 
proved that they have a deciduous placenta, and therefore it must 
be at this point that the Dcciduata and the Indecidua join. The 
lemurs are harmless and melancholy nocturnal animals of a graceful 
form, and are chiefly confined to the islands south of Asia and east 
of Africa, and particularly to Madagascar. Their frequency on 
the islands of the Indian Ocean led the English naturalist Sclater GENESIS OF MAN. 
57 
to name this once continental, but now mostly submerged region, 
Lemuria, a circumstance to which Haeckel has given special promi- 
nence, by pointing out the many facts which conspire to justify us 
in the conjecture that here may have existed the true “ cradle of 
the human race.” The lemurs form the eighteenth stage in the 
anthropogenetic line. 
From the lemurs to the true apes, the transition is comparatively 
easy. They evidently developed out of the Brachytarsi, the Ste- 
nops forming the nearest approach to a connecting link. 
Linnaeus, with almost prophetic ken, notwithstanding his dual- 
istic proclivites, classed man with the apes, lemurs, and bats, in 
his celebrated order, Primates. Blumenbach fancied he saw in the 
human foot a pretext for rescuing man from this association, and 
accordingly erected for him a separate order, which he called 
Bimana (two-handed), distinguishing the apes, etc., as Qnadru- 
mana (four-handed). This classification was adopted by Cuvier, 
and is the one which has generally prevailed among naturalists, 
down to Huxley and Haeckel. Huxley, however, gave the whole 
subject a complete re-investigation, and arrived at the conclusion 
that Blumenbach’s order Bimana cannot be maintained on anato- 
mical grounds. He shows, in the most convincing manner, that 
the distinctions alleged to exist between the posterior hands of 
apes and the feet of man are apparent only, that they were based 
on physiological and not on morphological considerations. The 
apes are just as good bimana as men are, and men are just as 
good quadrumana as the apes. In neither are the posterior limbs 
in all respects homologous to the anterior. The tarsal bones are 
differently arranged from the carpal bones, atnd there are three 
distinct muscles serving to move the foot that are wholly wanting 
in the hand. But all this is as true of the apes as of man. The 
limited opposability of the great toe in man is only a functional 
distinction. The muscles of opposability are all present; they are 
merely atrophied by disuse and adaptation to altered conditions. 
Traces of this power are found in many savages, who hold on with 
their toes to the branches of trees in the forests where they live, 
and otherwise employ this posterior thumb in a variety of ways 
which Europeans cannot imitate. There are, moreover, many 
instances on record of men acquiring extraordinary dexterity in 
the use of their toes. Every one in this country has seen the exhi- 58 
GENESIS OF MAN. 
bitions of the armless man, who travelled through our towns and 
displayed marvellous feats performed with his toes. Again, infants 
make far more use of their great toes than adults do. Watch a 
new-born babe as it lies in its cradle and amuses itself with exer- 
cise of its muscular activities; compare the movements of its 
hands with those of its feet, and you cannot but be struck with the 
comparative indifference with which it manages both. The human 
foot, whose careful study has been said to constitute a sure cure 
for atheism, and whose wonderful adaptation to the purpose to 
which it is applied has been regarded as an unanswerable argument 
for the doctrine of design, can therefore be nothing more than a 
natural result of the modification of the posterior hand of the ape, 
in simple obedience to the mechanical law of adaptation to changed 
conditions, while in it are found all the visible elements of that 
ancestral organ which the equally monistic law of heredity has 
transmitted from our simian progenitors. Huxley, therefore, re- 
stores the Linnaean order Primates, removing only the Chiroptera. 
Haeckel, however, would adhere to his order Prosimiae, the lemurs, 
for the reasons above stated. 
The true apes are primarily divided into two great groups, which 
are as distinct geographically as they are anatomically. These are 
the Catarrkinac or Old World apes, and the Platyrrhinae, or New 
World monkeys. They differ chiefly in two important respects. 
The Platyrrhinae have a flat and broad nose, like other animals. 
The nostrils open outivardly, and are separated by a broad interval. 
They have, also, thirty-six teeth, eighteen in each jaw. In both 
these respects they differ from man. The Catarrhinae, on the 
other hand, have a somewhat projecting, laterally compressed, and 
often arched or aquiline nose, with the nostrils close together and 
opening downwards. They have only thirty-two teeth, or sixteen 
in each jaw. In both these respects they agree with man. The 
clear-cut, much projecting, and elegantly formed nose of the Nose- 
ape (Scmnopithecus nasicus) would adorn the face of any European 
nobleman, while the countenance, taken in its ensemble, of Cerco- 
pithecus pctaurista would be sure* to call to any one’s mind some 
not very bad-looking person of his own acquaintance. And yet 
these handsome apes are endowed with long tails. Not only is 
the number of the teeth of the Catarrhinae the same as in man, 
but they are distributed in precisely the same manner, namely:— GENESIS OF MAN. 
59 
four incisors, two canine or eye-teeth, and ten molars or grinders, 
in each jaw. 
The Catarrhinae are further divided into two groups of tail- 
bearing and tailless apes. The tail-bearing apes have most proba- 
bly been developed directly from the lemurs, and therefore con- 
stitute the nineteenth stage in the descent of man. Our ancient 
forefathers in this group were perhaps similar to the now living 
Semnopithccus, from which the tailless apes, forming the twentieth 
stage, were differentiated chiefly by the loss of their tail.. These 
latter bear the greatest resemblance to man, and are called anthro- 
poid apes, constituting the family Anthropoides. The family con- 
sists, as far as known, of but four genera, Hylobates, the Gibbon 
of southern Asia; Satyr us, the Orang of Borneo and the Sunda 
Islands; Engeco, the Chimpanzee of southern and western Africa, 
and the Gorilla, first discovered by the missionary Wilson, in 1847, 
on the Gaboon River, western Africa, and afterwards by Du 
Chaillu. The Gorilla is the largest of known apes, and exceeds 
the human stature. 
To none of these four anthropoid apes, however, can we point 
as being in all respects the nearest to man. The Gibbon resembles 
man most in the form of the thorax, the Orang in the development 
of the brain, the Chimpanzee in the formation of the skull, and 
the Gorilla in the differentiation of hand and foot, and also in the 
relative length of the arms. It is therefore evident that man can- 
not have descended directly from any known living ape. His real 
progenitor must, in a greater or less degree, have combined all 
these characters, and has no doubt been long extinct. It is from 
paleontology that we alone hope for aid in the discovery of this 
“missing link.” The fossil remains of this extinct genus (Pithecan- 
thropus) may be looked for with some confidence in the still little 
known . region of south-eastern Asia, the Malay Archipelago, and 
throughout central and western Africa. 
The comparative anatomy and osteology of these four genera 
of anthropoid apes have been exhaustively studied by Carl Vogt, 
Huxley, and others. The final cdnclusion to which Huxley comes, 
and which he expresses in the most unqualified and emphatic 
manner, is that no matter what system of organs we take, a com- 
parison of the modifications in the Catarrhine series leads to one 
and the same result: that the anatomical differences that distin- GENESIS OF MAN. 
guish man from the Orang, Gorilla or Chimpanzee, are not as great 
as those which distinguish these latter from the lower Catarrhinae 
(Cynoccphalus, Makako, Ccrcopithecus). Therefore, as Haeckel 
remarks, it is incorrect to say that man has descended from the 
apes; he is himself an ape, and belongs as strictly to the Catarrhine 
group as the Gorilla or the Orang-outang! He therefore estab- 
lishes another family within that group, together with the Anthro- 
poides, which he calls the Erecti or Anthropi. This family he 
divides into two genera, the first embracing the now extinct ances- 
tor of the human race, the Pithecanthropus or ape-man, which 
therefore forms the twenty-first genealogical stage, and the second 
being the genus Homo, or man as we find him, forming the twenty- 
second and last stage in his development from the moner. 
Three anatomical distinctions of any importance are all that 
exist to separate the two families Anthropoides and Anthropi. One 
is the more erect posture of the latter—a difference of degree, 
however, which varies both with the apes and with men. The 
second is the higher brain development of the latter, which is also 
only a quantitative distinction. The third and only distinction 
which can be called qualitative, is the differentiation in the An- 
thropi of the larynx into an organ of speech. And not even this 
much can now be fairly said, since it is found that the larynx of 
monkeys exhibits a much higher state of development than that 
of other animals.10 Haeckel, however, regards Pithecanthropus as 
a speechless man, having the erect posture and differentiated brain, 
but who had not yet acquired the power of articulate language, or 
the necessary organs for its utterance. For this reason he offers 
also a synonym for his name Pithecanthropus, the equally appro- 
priate one, Alalus, the speechless. This, however, is only theory. 
In point of fact, the erect posture, size and quality of brain, forma- 
tion of vocal cords, and the origin of articulate speech, must have 
all advanced pari passu, mutually promoting one another, and 
developing by insensible degrees, according to the universal 
method of all nature. 
To the various races of men as recognized by ethnologists, 
Haeckel, in harmony with his general system, gives the rank of 
species of the genus Homo. All definitions of the term species 
10 Emile Blanchard, “ Voice in Man and Animals,” in Popular Science Monthly, 
September, 1876, page 519. GENESIS OF MAN. 
61 
having failed to unite upon any absolutely constant character as a 
condition to its application, the use of it here is justifiable, not- 
withstanding the ease with which the human races hybridize, and 
no matter what theory may be preferred of their origin or rela- 
tionships. Of these species he makes out twelve, and advances an 
interesting theory of their origin and geographical distribution 
over the globe; but upon this new field we can here follow him 
no farther. 
In casting a retrospective glance over the vast subject thus 
hastily passed in review, there are a few salient points which will 
have most probably, in an especial manner, struck the mind of the 
reader. 
One of these is likely to be the great brevity of the anthropo- 
genetic line,—considering the variety and multiplicity of living 
forms found on the globe. We perceive that of the seven sub- 
kingdoms of animals now recognized, only three are touched by 
it, viz ;—the Protozoa, Worms, and Vertebrates. The zoophytes, 
echinoderms, anthropods, and mollusks all branch off either below 
or at the worm stage, and the transition from the Tunicata, a 
worm-form, is direct to the vertebrata. This, when adequately 
appreciated, is an astonishing fact, and one which would never 
have been conjectured but for positive anatomical evidences. 
Those who believed in a law of development were looking vainly 
for proof of the derivation of the different types one out of anoth- 
er, and discussing which should be considered lowest, the articu- 
lates or the mollusks. They expected to find proof of a series 
with the radiates at the bottom and the vertebrates at the top. 
The truth, as it has at last dawned upon us, dispenses with all such 
speculations. 
Equally surprising is the shortness and directness of the transi- 
tion from the lowest to the highest vertebrates, from the Amphi- 
oxus to the Ape. All the vague surmises of some extensive 
course of descent and lineal relationship among the numerous 
classes and orders of vertebrates are now also brought to an end. 
The higher fishes and higher amphibians, the reptiles and the 
birds, are all left to pursue special routes of their own; and a brief 
series of easy and rapid transitions through the lowest fish-form, 
the Selachia, and the lowest amphibian-forms, the Sozobranchia 
and Sozura, brings us at once to the lowest mammalian stage. 62 
GENESIS OF MAN. 
But perhaps the most surprising part of this whole course is its 
one great stride through the entire mammalian class, from the 
marsupial to the lemur. All vain expectations of finding some 
thread of relationship that should lead through the labyrinth of 
varied mammalian orders, and connect us with the horse, the dog, 
the elephant, etc., are thus happily set at rest, and we are permitted 
only to claim such consanguineal relationship with the opossum, 
the lemur and the ape. 
In fact, instead of a long concatenated “chains animals S as La- 
marck supposes, the animal kingdom presents rather a tree, spread- 
ing from very near the base with almost a whorl of unequal 
branches or subordinate trunks, each of which is again variously 
branched, giving the whole the form of an inverted cone or pyra- 
mid. At the upper extremity of each of these branches, which 
have come a long way independently of each other, is found one 
of the great groups or types of now living creatures, man occupy- 
ing the highest summit of the vertebrate branch. 
Contemplating now the great number of branches that arise at 
different points, some of which are short and apparently stunted, 
while others push upward with different degrees of vigor, only 
one or two reaching truly lofty and commanding positions, the 
thought forcibly strikes us that this picture reveals the universal 
tendency of Nature to develop organic forms. We realize that 
this vital force or nisus is constantly pressing at every point, but 
that as the conditions of life are limited, success is possible only at 
a few points; that in consequence of obstacles of many kinds, not 
the least of which are offered by organic conditions themselves 
that have pre-occupied the field, the degree of success at these 
points varies widely, and produces all grades of vigor, size, length, 
and ramification among the branches. The highest and most 
thrifty branches mark the line of absolutely least resistance; the 
shorter and less vigorous ones indicate lines offering varied degrees 
of resistance; while the stunted, dwarfed, and retrograde branches 
show lines of resistance so great that the vital force barely over- 
comes it. Finally, all points from which no buds or branches 
arise teach us over how large a proportion of nature the resisting 
agencies wholly overbalance the organic tendencies, and no life 
can originate. 
Another thought to which the attentive contemplation of this GENESIS OE MAN- 
63 
theme gives rise, is the greater antecedent probability of like 
organs, occurring in different animals, being homologous, than of 
their being analogous. The conditions in which life finds itself 
placed are so infinitely variable, that the chances are almost infinity 
to one against the development of the same organ independently 
at two different times and places. Where the same organ is unex- 
pectedly found in two animals which had not been supposed to be 
at all related, it affords the strongest evidence that they are either 
immediately connected by blood, or at least that they have both 
descended from a common ancestor that possessed that organ. 
Hence the irresistible force of the testimony afforded by the so- 
called “ rudimentary organs,” which none but those who realize 
this important law can properly appreciate. That analogues do 
sometimes occur, in obedience to the law of adaptation, cannot, 
however, be denied; but they usually betray their origin by being 
formed on an essentially different principle, though in such a man- 
ner as to accomplish the same purpose. The wings of birds, bats, 
and insects are such cases of analogy, in each of which the morpho- 
logical differentiation is wholly different, while the physiological 
function is the same. The beak of the Ornithorhynchus is perhaps 
as near an approach as we have to a true morphological analogue, 
the descent of that animal from the birds being overruled by a 
preponderance of evidence against it. 
It is this principle, too, which conclusively negatives the pre- 
sumption which some have advanced, that the aborigines of 
America may have descended from the New World monkeys. 
Catarrhine man could never have sprung from a Platyrrhine ape. 
It is, moreover, this same biological law which justifies Haeckel 
in the assumption of so many hypothetical and long-extinct ances- 
tral forms, although no warrant for them is afforded by paleonto- 
logy. The Gastraea, the Chordonium, the Protamnion, the Pro- 
mammalia, and the Pithecanthropus are all creatures, not of his 
imagination, but of stern logic, based on a profound familiarity 
with all the facts and principles that bear upon the problem. The 
common origin and blood relationship of all creatures that possess 
a spinal column, of all that are endowed with five-toed feet, of all 
that develop an amnion, of all that have the double occipital con- 
dyle, of all that suckle their young, of all having the fore and hind 
feet differentiated into hands, of all that have the catarrhine nose 64 
GENESIS OF MAN. 
and identical dentition—these are propositions whose demonstra- 
tion, by the aid of the law of heredity, is as complete and absolute 
as that of any proposition in Euclid. There is no other way to 
account for these facts. The chances of these organs being so 
many independent morphological analogues, produced by adapta- 
tion to identical conditions, are but as one to infinity. 
Either the dualistic conception of teleological design, i. e., mira- 
cle, must be admitted, or else there is no alternative from this ex- 
planation.