ON THE CAUSES OF VARIATION IN ORGANIC FORMS. 
ADDRESS 
BY 
C. V. RILEY, 
Vice President, Section F, 
BEFORE THE 
SECTION OFBIOLOGY, 
AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE. 
At the Cleveland Meeting, 
A U G U S T, ^88- 
From the Proceedings of the American association for the Advancement 
of Science. Vol. XXXVII. 
PRINTED AT THE SALEM PRESS 
SALEM, MASS. 
1888. ON THE CAUSES OF VARIATION IN ORGANIC FORMS. 
ADDRESS 
BT 
0. V. RILEY, u 
Vice President, Section F, 
BEFORE THE 
SECTION OF BIOLOGY, 
AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE. 
At the Cleveland Meeting, 
August, 1888. 
From the Proceedings of the American Association for the Advancement 
of Science. Vol. XXXVII. 
PRINTED AT THE SALEM PRESS. 
SALEM, MASS. 
1888. ADDRESS 
BY 
C. V. RILEY, 
VICE PRESIDENT, SECTION F. 
ON THE CAUSES OF VARIATION IN ORGANIC FORMS. 
Ladies and gentlemen : 
But few alternatives are left your vice president in choosing a 
subject for this annual occasion. With the modern world-wide ac- 
tivity in biology, to give a review, however condensed, of the prog- 
ress and discovery of the year, would require far more time than 
can be given by one who yields to the pleasure and fascination of 
original research what little time can be snatched from the slavery 
of official routine and administration. Any such general review, 
if attempted, could not be critical or authoritative beyond the limits 
of one's own specialty, and the task is now well done by the com- 
bined efforts of a number whose work we get in the German and 
English records. 
" One science only will our genius fit, 
So vast is art, so narrow human wit." 
To give a similar review of progress in one's own specialty would 
be to interest but a limited number. I have decided, therefore, to 
give expression to a few thoughts which have occupied my mind for 
many years, on the laws of biologic evolution, and particularly on 
the causes of variation in organic forms. I have been helped to 
this decision by the appearance, since last we met, of the " Life and 
Letters" of the immortal Darwin and the loss from among us of 
the mortal presence of our own beloved Gray. Both men, in their 
work, gave eminent illustration of the fact that the subjects which 
3 4 
SECTION F. 
I thus take for text may be approached and elucidated from quite 
different roadways or beginnings. These subjects are, moreover, of 
still absorbing interest; for we recognize that in evolution is locked 
up the origin of man, just as in it are involved his present and his 
future, subjects which from time immemorial, or from the earliest 
infancy of the race, have deeply concerned him. The demonstra- 
tion of the fact, the establishment of the law of organic evolution, 
have given fresh impetus to inquiry. To know something definite 
of the past but intensifies our desire to read in that past some 
prophecy of the future. 
Evolution, as a fundamental principle in organic nature, is to- 
day more thoroughly established and proved in the mind of the 
average biologist than the Copernican theory itself. 
From the time when Aristotle prophetically remarked that "Na- 
ture passes so gradually from inanimate to animate things, that 
from very continuity the boundary between is indistinct," through 
the suggestive writings of Lamarck, Erasmus Darwin, Oken, 
Goethe, Balden Powell, Geoffroy-St. Hilaire, Wells, Chambers, 
Lyell and Spencer, the belief in biologic evolution was growing and 
expanding, until it ultimately blossomed in the simultaneous la- 
bors of Darwin and Wallace. 
Prior to the writings of these last it was necessary to fight for 
the general principle, and long after the appearance of the "Origin 
of Species" there was a violent clash between the advocates of 
special Creation and those of Evolution ; so that much as Darwin 
felt and cared for natural selection he was in the beginning more 
interested in settling the question of "Creation vs. Modification." 
The fight has continued with ever-waning forces on the part of the 
creationists,1 until to-day the evolutionists are victorious and no 
longer under the necessity of marshalling the facts to bring convic- 
tion to the skeptical. Thus biology, the last stronghold of the 
creationists, has been brought into correspondence with chemistry 
and physics, in which the opponents of evolution had long before 
given way. The clearing of the smoke on this last battlefield is 
comparatively so recent that, in the popular mind, evolution yet 
applies only to the organic kingdom, and it is in this more limited 
sense that we, as biologists, particularly use the word, and in which 
I shall use it for the most part in this address. We depend for 
1 The term is used in the theological sense of creation by supra-natural means. Ev- 
olution is also creation, but by natural process. ADDRESS BY C. V. RILEY. 
5 
evidence on an immense number of well ascertained facts, so that 
the proofs of organic are often stronger than of inorganic evolu- 
tion. Phylogeny, or the geologic succession of life, as proved by 
palaeontology, finds its correspondence in Ontogeny, or the devel- 
opmental history of the individual, particularly in its embryonic 
phases; while both find correspondence in Taxology, or the rela- 
tionship of organic forms now existing on our globe. The corre- 
spondence, one with the other, of these three great series is one of 
the most pregnant facts of biology and inexplicable on any other 
theory than that of derivation. It is the essence of evolution that 
the present more complex forms are derived from older and simpler 
forms and that the greater the difference between groups the great- 
er the divergence and the deeper down the converging stem or an- 
cestry. We are justified in concluding that complete knowledge 
(were that possible) would permit us to trace back the origin of 
every organism to the simple unicellular, ancestral form. I would 
hardly second the strictures of a former vice president of this sec- 
tion on the " scientific arboriculturists," because philosophy must 
needs lead from the known to the unknown, and the value of a phy- 
logenetic table depends on the knowledge and ability displayed in 
projecting it and on the plausibility of those parts which are not 
based on palaeontological facts-and perhaps never can be-but 
which the facts of embryology suggest. Biologic evolution implies, 
further, what has hardly been sufficiently emphasized, (1) increase 
in size or bulk as correlated with the increasing diversity and com- 
plexity of organization ; (2) that the most highly organized require 
(comparatively) the longest time for development both in the foetal 
and postnatal states, and (3) that large organisms with complex 
structure are more sensitive to changes of condition and more lia- 
ble to extinction ; and this means that the larger the size and the 
higher the development, the fewer in number both as to species and 
specimens. 
These principles, now so generally accepted, aside, let us at once 
throw a coup d'ceil over some of the factors of evolution and see 
what we understand of the causes of variation and differentiation, 
as this is the question of questions among biologists to-day. 
The essence of Darwinism as an element in evolution, viz., 
"natural selection," was original with several, and Darwin him- 
self remarks, in his autobiography, that an essay in Hebrew had 
been published showing that the theory is contained in the Old 6 
SECTION F. 
Testament. He also recognized that Bronn in his " Geschichte 
der Natur" forestalled him in many ways. Even as early as 1766 
Duchesne wrote profoundly of the lines of variation and evolution, 
and showed that a genealogical order is the only one which satis- 
fies the mind, all others being arbitrary; and he ventured a gen- 
ealogical tree based upon profound knowledge and ascertained 
facts in the natural history and cultivation of the strawberry. The 
principle was also fully recognized in 1813 by Dr. W. C. Wells of 
Charleston, S. C., and in 1831 by Patrick Matthews, as later edi- 
tions of the "Origin of Species" set forth. Such, however, is the 
history of all great theories. They cannot be cast at once full- 
panoplied and impregnable like Minerva from Jove's head. Great 
discovery is usually more or less definitely foreshadowed. 
The publication of the " Origin of Species," however, marked a 
new epoch in biology and the work has profoundly influenced mod- 
ern thought. Yet Darwin's fame rests just as firmly upon that 
vast structure of facts which he so successfully brought together 
in his various writings, as it does on his theories ; and had he never 
propounded the theory of Natural Selection, his writings would have 
immortalized him, for they form an encyclopaedia of well-arranged 
data for the naturalist, the agriculturist, and the stock-breeder. 
He threw the light of his genius into recesses formerly obscured 
and opened new vistas through old problems which had previously 
defied elucidation. 
It would require volumes even to indicate the extent and char- 
acter of the literature upon evolution since the appearance of the 
" Origin." The proceedings of this section of the American Asso- 
ciation during a quarter of a century have been, in a measure, typ- 
ical of the proceedings of like bodies the world over, and constitute 
a record of the discussions and of the progress of thought and ex- 
perience in this direction. We have every reason to be proud of 
the work of American biologists as illustrated in this record ; for, 
notwithstanding the vagaries of a Swallow, and the more able and 
serious opposition of a Dawson, belief in the derivative origin of 
species has steadily gained among biologists and now includes all 
those whose work and word are worthy of consideration. We may 
be proud, also, of the demonstrative proof which members of this 
section have brought to bear upon the general theory, as also of 
the newer thought and far-reaching generalization original with 
other members of the section. ADDRESS BY C. V. RILEY. 
7 
In looking over this record two things strike me as worthy of 
further consideration. On the one side there has been a dispo- 
sition to widen the meaning of the term "Natural Selection" so as 
to include the cause, or causes, as well as the method, of variation 
and modification. On the other side, the tendency has been to 
the opposite extreme or to limit the application of the term to the 
mere selection of the fittest, so that it becomes but the expression 
of a common and easily observed fact in nature, without involving 
any of the more fundamental principles of evolution. It becomes 
merely a means or method and in no sense a cause of modification. 
Some writers even go so far as to insist that while it is all power- 
ful in originating genera, i. e., in producing adaptive structure, it 
has little or nothing to do with the production or origination of 
species and they would thus render the very title of Darwin's great- 
est work a misnomer. 
It may not prove unprofitable to note what the "Life and Let- 
ters" have to say upon this question, and to see what limit, if any, 
Darwin himself placed upon the term. It is of prime importance 
that we use it in as accurate a sense as possible, since it has played 
such an important part in the literature of, and expresses such an 
important factor in, evolution. The book is most interesting and 
suggestive; for we not only get from it an insight into the per- 
sistent and laborious effort which resulted in Darwin's enduring 
fame, and left so deep an impression on the scientific work of his 
generation; but we come to realize how he labored in giving his 
thought that forceful, logical, yet simple expression which had so 
much to do in making his work popular ; how the candor of his ar- 
gument and statement was but the reflex of the candor and honesty 
of his mind. We learn to appreciate more fully the vast range of 
knowledge he possessed of scientific fact, both from personal ex- 
perience and authority, and how he bent it to one great end. We 
come to love him for his many beautiful personal traits ; his noble 
character ; his simplicity ; the courage with which he bore up under 
bodily ailment; and for his humanity to animals, which is well 
brought out by interesting anecdotes given by his son. We honor 
him for his strong feeling and sympathy with suffering, both in man 
and beast; for his horror at the suffering of slaves, which inclined 
him strongly to the Union side in our Rebellion but did not blind 
him to what, from the average English standpoint, were the polit- 
ical issues at stake ; just as his sensitiveness to the suffering of 8 
SECTION F. 
animals did not warp his position on the question of vivisection, 
which he believed to be justified for investigations in physiology. 
In scanning the pages of his personal record we come to realize 
fully that 
"His life was gentle; and the elements 
So mixed in him that nature might stand up 
And say to all the world- 
This is a man!" 
But aside'from the insight which the book gives into the lovable 
character of the man, and of his method of work, it is replete with 
thought and fact, and may be looked upon almost as an appendix 
to the "Origin." Let us see, therefore, what light it throws on the 
question we have propounded. 
The actual causes of variation may be few or many-remote or 
immediate; but their discovery or non-discovery no more affects 
the principle of natural selection than the difficulty in elucidating 
the causes of gravitation affects it as one of the grandest discov- 
eries and generalizations of our age. We may come to understand, 
and are already able to elucidate some of the proximate causes, 
but the consideration thereof inevitably leads us back farther and 
farther to the great First Cause, and Darwin's work would never 
have had so profound an influence had he, instead of basing his the- 
ories on demonstrable and experimentive fact, been led into the 
more speculative realms of causation. Not but that he was in- 
tensely interested in the causes of variation ; for we have his own 
words and those of his son to show the ever-present desire in his 
mind to learn something thereof. But he avoided consideration of 
them in the same way that he avoided speculation on the origin of 
life itself, seeing clearly, no doubt, that both questions lead ulti- 
mately to Infinite Causation and that this is beyond man's finite 
comprehension, in his present state of development, at least. 
In a letter to Lyell, September 12, 1860, in response to a ques- 
tion why rodents have not become more highly developed in Aus- 
tralia, he says: "I feel that our ignorance is so profound, why one 
form is preserved with nearly the same structure, or advances in 
organization or even retrogrades, or becomes extinct, that I cannot 
put very great weight on the difficulty." Again, Feb. 23, 1860, 
he says : "With respect to Bronn's objection that it cannot be shown 
how life arises, and likewise to a certain extent Asa Gray's remark 
that natural selection is not a vera causa, I was much interested by ADDRESS BY C. V. RILEY. 
9 
finding accidentally in Brewster's 'Life of Newton' that Leibnitz 
objected to the law of gravity because Newton could not tell what 
gravity itself is.* * * Newton answers by saying that it is philo- 
sophical to make out the movements of a clock, though you do 
not know why the weight descends to the ground." 
We may now consider the question of natural selection itself, and 
see whether, as the expression of a principle, it may not be more 
strictly defined than it was by Darwin himself. 
We find in his correspondence with Wallace that the latter states 
that the term " survival of the fittest" is the plain expression of a 
fact. Natural selection, on the contrary, is a metaphorical expres- 
sion of it, but to a certain degree indirect and incorrect. The great 
objection which Darwin urged to the term "survival of the fittest" 
was that it could not be used as a substantive governing a verb, 
which obliged Spencer himself continually to use the term " nat- 
ural selection." Darwin recognized, however, the force of the ob- 
jections to the term, and yet it would be difficult to find a better, 
and his final preference, after long deliberation and correspondence 
with men like J. D. Hooker, has justified his judgment. Wallace 
noticed that Darwin had used the term in two senses -.first, for the 
simple preservation of favorable and destruction of unfavorable 
variations, in which case, according to Wallace, it is equivalent to 
the "survival of the fittest," and secondly, for the effect of the 
change produced by this preservation. In his autobiography, Dar- 
win says : " But it was clearly evident that neither the action of 
the surrounding conditions nor the will of the organism (especially 
in the case of plants) could account for the cases in which organ- 
isms of every kind are beautifully adapted to their habits of life." 
Nothing can be more characteristic than the following in his long 
letter to Lyell, October 11, 1857. "It has taken me so many 
years to disabuse my mind of the too great importance of climate 
-its important influence being so conspicuous, while that of the 
struggle between creature and creature is so hidden-that I am in- 
clined to swear at the North Pole and, as Sidney Smith said, even 
to speak disrespectfully of the Equator." In a letter to Victor 
Carus we find him inclined to place more value on the definite ac- 
tion of external conditions, and to infer that single variations are 
of less importance in comparison with individual differences than 
he formerly thought. 
I recollect well, while visiting him in the fall of 1871, that he 10 
SECTION F. 
expressed very much the same views which he has expressed in a 
letter written about that time to Huxley, in which, using the illus- 
tration of a pendulum, he says : " The pendulum is now swinging 
towards our side and I feel positive that it will soon swing the 
other way." He realized that there would be oscillations in the 
popularity and general acceptance of his views and especially as to 
the part of natural selection as an originating power. 
Thus his own views as to the value, scope and bearing of nat- 
ural selection, varied to some extent, and he used the term in two 
different senses. In the broader sense, as used by him, and by 
many of his followers, notably in this country by Fiske, Morse, 
Marsh, etc., it is a great principle of modification that includes both 
the fact of variation from whatever cause or causes and the ex- 
planation of accumulative divergence along beneficial and adap- 
tive lines. It involves the Malthusian struggle for existence, not 
only among the organisms themselves but with the elements and 
the environment. 
It is plain from Darwin's own writings that a term to express the 
principle was not easily found and the difficulty was doubtless 
due to the uncertainty that existed in the author's mind, as it has 
existed in the minds of his followers, as to the exact limitations 
of the principle. The term is happy in my judgment, because it 
has permitted the focussing of definition by subsequent elucidation. 
Darwin could but feel that " Wahl der Lebensweise," as a German 
translation, hardly expressed his opinion, and he was right; " nat- 
urliche Zucbtwahl," the later translation adopted, being far pref- 
erable. 
As propounded by him, natural selection deals essentially with 
the variation of the individual under like conditions, as distin- 
guished from the variation of the type under change of environ- 
ment. He impersonates by the term an ensemble, i. e., a number 
of innate conditions of variation. The principle is, in fact, based 
upon the Leibnitzian axiom "Natura non agit saltatim," and it 
finds a counterpart in the facts of artificial selection induced by man 
which, in reality, led Darwin to adopt the term to express selection 
by nature. But here it must distinctly be borne in mind that by Na- 
ture, though it is difficult to avoid personifying it, he meant "only 
the aggregate action and product of many natural laws,- and by 
laws only the ascertained sequence of events. He found it difficult 
to admit of any personality or designer in any way using natural ADDRESS BY C. V. BILEY. 
11 
selection for designed ends, so that the comparison with artificial se- 
lection by man lacks in one most important particular ; but we may 
recur to this point later on. Natural selection is a great principle, 
the promulgation of which revolutionized biology. It is a modus 
operands of derivative genesis, embodying two somewhat opposing 
laws, namely, heredity and adaptation ; the former for the most part 
conservative and tending to cause organisms to hold to the past, 
the latter progressive and tending to cause them to diverge or 
ramify. It is a quo modo of succession, but it implies no necessary 
tendency to progression, however much such progress may be indi- 
cated in the general history of evolution. Certain simple conditions 
of life may have persisted from before the Silurian age to the pres- 
ent day, and the one primordial prototype of all living and extinct 
creatures may still exist so far as natural selection is concerned. 
It is a principle universal in its action, explaining one important 
mode of modification and differentiation of forms, especially among 
higher animals or where the interests of highly endowed or organ- 
ized beings most strongly interact to give it effect. It must be less 
effective among lower organisms, where external conditions are evi- 
dently prepotent in inducing not only variation but specific modi- 
fication. Natural selection, therefore, does not satisfy us as an ex- 
planation of the original differentiation of the great classes, and it 
was perhaps a certain recognition of this fact which caused Darwin 
to pause on the safe side of their differentiation and not endeavor 
to explore the deeper mysteries beyond. Yet after all it is among 
these lowest forms that the key to the explanation of the more im- 
portant factors in evolution must be sought. 
The Darwinian, therefore, who would give fullest expression to 
the teachings of the master, employs the term in a broad sense as 
the expression of a principle in nature which explains how the fit- 
test have come to be preserved, and hence the mode of formation 
of species. The " formation" would have been a happier expres- 
sion than the "origin" of species, but not so good a catch-title, and 
we should never forget that the sub-title of the immortal work, 
viz., "The preservation of favored races in the struggle for life," 
more fully expresses the author's meaning. By its too zealous ad- 
vocates natural selection has been used to explain phenomena due 
to other causes. This is, however, a danger that all great discov- 
eries encounter; they are made to do service for which they were 
not originally propounded. But the opposite tendency, when car- 12 
SECTION F. 
Tied to extreme, is equally unjustified and would obliterate natural 
selection as a factor in evolution. 
Spencer's expression the "survival of the fittest" has often been 
used as synonymous with natural selection, to the detriment of 
the latter; for while all must recognize the aptness of the term, as 
a somewhat tautological expression of the result, it can never be 
made to cover the principle involved in the Darwinian term. It 
is an explicit and forceful expression of the fact and in no sense 
of the theory. Natural selection deals not so much with the sur- 
vival of the fittest as with the destruction of the unfit. It expresses 
a cause of differentiation or formation of species and higher groups, 
in a sense in which the "survival of the fittest" does not, however 
little either term may explain the causes of variation per se or the 
origin of the individual variation. It operates under subjection, 
taking advantage of variation otherwise initiated ; or, to use Spen- 
cer's language, it expresses an effect of the mode of cooperation 
among causes. We are justified, therefore, in saying that natural 
selection is the essence of Darwinism and is a fundamental prin- 
ciple in organic evolution based on (1) individual variation and 
(2) the struggle for existence and preservation of the most com- 
petent. Other factors of less importance help to give it potency. 
It is based upon the facts as they may be observed, and the whole 
superstructure is built upon the innate variability of individuals, 
irrespective of conditions. The difficulty of getting at the imme- 
diate cause or causes of this individual variation led Darwin to 
consider it promiscuous or aimless, though he wisely avoids calling 
it lawless. He felt, as we have already seen, that there were causes 
and that of the majority of these we were ignorant. In his own 
words, "we can so rarely trace the precise relation between cause 
and effect, that we are tempted to speak of variations as if they 
arose spontaneously. We may even call them accidental, but this 
must be only in the sense in which we may say that the fragment 
of rock dropped from a height owes its shape to accident." 
I have always had a feeling, and it has grown on me with in- 
creasing experience, that the weak features of Darwinism and hence 
of natural selection, are his insistence (1) on the necessity of slight 
modification ; (2) on the length of time required for the accumula- 
tion of modification, and (3) on the absolute utility of the modi- 
fied structure. I think that Darwin laid altogether too much stress 
on these points, and that while, in the main, insistence thereon ADDRESS BT C. V. RILEY. 
13 
is justified, a too strict adherence to them weakens natural selec- 
tion as a true expression of the phenomena of modification. This 
is particularly true of lower organisms among which, as we have 
already seen, natural selection has been and is necessarily less po- 
tent than among the more highly organized and complex, from 
which, especially under domestication, Darwin drew most of his 
evidence. 
Whatever influence we may attach to environment and external 
conditions, it is self-evident that they alone have not been sufficient 
to induce the wonderful variety of life existing upon the globe to- 
day. Indeed, so far as natural selection implies necessary utility, 
necessary adaptation to surroundings, it is, as I have said, defect- 
ive. We know very well that introduced species from one conti- 
nent to another, or from one country to another, have proved 
better adapted to the changed conditions than the indigenes or 
endemic forms. This is readily comprehended on two grounds ; 
first, that species which have, in the course of time, experienced 
a greater struggle among themselves in large areas, have an ad- 
vantage over those in more limited areas in which the struggle lias 
been less intense ; secondly, that species which have accommodated 
themselves to the changes in life conditions which civilized man 
induces, have a great advantage when, following man's migrations, 
they are brought into competition with species which have not yet 
been subjected to such conditions. Again, no valid reason can 
be urged why, within a given area, one species predominates over 
another in so far as mere adaptation is concerned. The influences 
of environment alone would tend to unify the fauna and flora of a 
given region. Theoretically, so far as climate and physical con- 
ditions are concerned, there is no reason, through regions where 
these are uniform, why a single animal should not prevail to the 
exclusion of all others, providing it was vegetarian, or that the 
particular plant which furnished food to such an animal should not 
prevail to the exclusion of all others. The hickory and the blade 
of grass must be considered equally adapted to the environment 
with the oak, and so on all through the multifarious forms of both 
vegetal and animal life : so that this diversity of form can best be 
explained by some principle like natural selection, and by the in- 
terrelation and interaction of organisms and the struggle between 
them for existence. This is illustrated in many directions. To 
take a striking example : no one doubts that if the larger carnivora 14 
SECTION F. 
of Europe and Asia were introduced into Australia, the marsupials 
would soon have to give way and could survive only by the acqui- 
sition of special functional modifications and larger intelligence 
such as we find in our opossum. Yet it would be folly to conclude 
that the marsupials are less well fitted to the physical conditions 
which obtain in Australia than their introduced exterminators. 
From what has preceded, we are, I think, justified in rejecting 
the interpretations of both extremists as to the scope and meaning 
of natural selection. It cannot be debased to the mere expression 
of the universally observed fact of variability ; yet it must be re- 
stricted, because it not only implies something to be selected, but 
its promulgator limits its scope to the selection of something that 
is useful. As a philosophy it considers only processes and leaves 
remote origin and cause untouched. The following limitations are 
probably justified to-day and will help to more exact use of the 
term. 
1. It deals only with individual variation from whatever cause, 
and should not be applied to simultaneous variation in masses. 
2. It deals only with variations useful to the organism in its 
struggle for existence, and can exert no power in fixing the end- 
less number of what, from present knowledge, we are obliged to 
consider fortuitous characters. It cannot perpetuate useless organs ; 
nor those of a vestigiary or obsolescent character.1 
Even with these restrictions, the principle is far-reaching and 
profoundly important; but it quite fails to account for many of the 
most interesting manifestations of life that are obviously not nec- 
essary or life-preserving, of which many will occur to every one; 
such as, among lower organisms, many superficial details of struct- 
ure ; or, as among higher organisms, odd habits and customs, play- 
ful instincts, ethical traits, etc. Its limitations must be narrowed 
in proportion as we come to understand the other laws of modifi- 
cation and the causes of variation in masses. Let us briefly con- 
sider some of these causes. 
While, as already stated, the consideration of this question in- 
evitably leads to Ultimate Cause, there is no more fascinating or 
profitable field of investigation than that leading to the proximate 
cause orcauses of variation. We are not content to rest the case 
where Dai win did by recognizing variation as an inherent principle 
1In the literature of evolution, these are usually termed rudimentary, but, strictly 
speaking, this term should be applied only to nascent or incipient structures. ADDRESS BY C. V. RILEY. 
15 
in organic forms, or to beg the question by saying that it is as 
much a necessity of life as natural selection itself. Let us, there- 
fore, discuss these causes in the light of recent experience and ex- 
periment. 
We soon find that they admit of a certain amount of classifica- 
tion, the minor divisions of which, as in all systems of classifi- 
cation, more or less fully interlock or blend. They fall, however, 
into two chief categories, viz. (1) external conditions or environ- 
ment, which are, at bottom, physical, and (2) internal tendencies or 
promptings, which are, at bottom, psychical. We shall also real- 
ize more fully that there is good reason for the varying importance 
which has been placed on natural selection because it represents a 
broad principle, based on the outcome of both these categories, but 
particularly of the latter. Its value is not a fixed one, and must 
needs change with the increase of exact knowledge of the other 
factors, and did in fact change in the mind of its originator. We 
shall further find that there are laws of evolution which permit 
of formulation and expression, and which have influenced or con- 
trolled the mode of variation, but which must not be confounded 
with or included among the causes of the variation proper, though 
here again, the line between the two kinds of factors is not always 
easily defined. 
The conditions of organic modification may, therefore, roughly 
be classed as (A) external and (B) internal, and these may be al- 
most indefinitely subdivided. The former class includes (1) phys- 
ical and (2) chemical forces and in a broad way may be said to 
induce modification independently of natural selection, however 
much this may act with them as a secondary cause. Certain promi- 
nent features of the physical forces are worthy of mention : as 
light, temperature, water (stagnant, or in motion), climate (under 
which term may be included meteorologic phenomena, as electricity, 
atmospheric pressure, etc.), mechanics (gravitation, wind, stress, 
friction, etc.) and geographies (migration, isolation, etc.). The 
chemical forces may be considered under the subdivisions, aquatic, 
atmospheric, food and soil. In class A may also be included 
(3) vital1 or organic force in so far as this is concerned with the in- 
11 am well aware that this term is much tabooed among a certain class of the more 
materialistic evolutionists, but I use it here for want of a better, and because as an ex- 
pression of one form of manifestation of force, it has as much a classiflcatory value 
as physical or psychical. 16 
SECTION F. 
teraction of organisms, and it is seen thus to link the two great 
classes. The second class (B) includes (1) physiological and (2) 
psychical forces. Prominent among the former, as causes of mod- 
ification, are worthy of mention those connected with genesis itself: 
as heredity, physiological selection, sexual selection, hybridity, 
primogenital selection, and what I would call sexual differentia- 
tion, and philoprogeneity. Among the latter may be included 
use and disuse, individual effort, etc.; and last, but not least, the 
emotions. 
As already stated, any such classification of the forces at work 
in organic evolution must be more or less arbitrary and artificial. 
Fundamentally also, they are, perhaps, convertible terras-unifia- 
ble - one. But some such arrangement as that here suggested 
serves to simplify discussion. 
Now with the limited definition given to natural selection, all 
the forces in class A act independently of it,.while the rest are 
more or less fully aids to its action. Time will not permit of 
much detailed consideration of the physical and chemical forces. 
Nor is such consideration necessary ; for their influence, as Dar- 
win well remarked, is obvious. Fundamentally, they must needs 
limit and control all manifestations of life of which indeed, on 
evolutional grounds, they are the material basis. Change of phys- 
ical environment may affect function first and chiefly, but this 
involves change of form and structure which are integrated by 
heredity. The surface of the earth and the waters upon it and 
the atmosphere above it, have necessarily conditioned the chief 
modes of animal locomotion as swimming, flying, crawling and 
walking, while the five great classes of vertebrates find the expla- 
nation of their structure, as J. B. Steere pointed out at the Ann 
Arbor meeting, in the conditions of life in water, in shallows, in 
the air, on land and on trees and rocks. 
External Conditions.-By external conditions or environment, 
we include all influences on organisms which act from without, and 
in carefully considering them we shall find it difficult to draw the 
line between those which are really external and independent of any 
motive or inherent tendency in the organism, and those which are 
not. Hence, the general term "External Conditions" is resolvable 
into various minor factors. Considering the influences as a whole, 
we find that in the 1844 essay, or sketch, Darwin gave more weight 
to them as producing variations, and as modifying habit, than he ADDRESS BY C. V. RILEY. 
17 
did in the "Origin" ; yet we all know that he felt convinced when this 
work was first issued, that natural selection was the main, though 
not the exclusive, means of modification. Before his death, he was 
again led to attach greater importance to them. As late as March, 
1877, he wrote to Neumayr, of Vienna, that " there cannot be any 
doubt that species can be modified through the direct action of the 
environment. I have some cause for not having more strongly in- 
sisted on this head in my ' Origin of Species,' as most of the best 
facts have been observed since its publication." He was led to 
this modification of his views by Neumayr's essay on "Die Con- 
gerien," and by Hyatt's work in showing that similar forms may 
be derived from distinct lines of descent. In his correspondence 
with Huxley, Darwin remarks that one point has greatly troubled 
him. If, as he believed, accidental conditions produced little di- 
rect effect, "What the Devil determined each particular variation? 
What makes the tuft of feathers come on the cock's head, or moss 
on the moss rose?" 
It is quite plain, indeed, that subsequent to the publication of the 
"Origin," and especially in 1862, in his correspondence with Lyell, 
Darwin was inclined to give more power to physical conditions, 
and, in fact, was wavering in his mind as to the force of the different 
influences at work. In his letters to Hooker in 1862, the same ten- 
dency may be noted and the preparation of the "Variation of ani- 
mals and plants, under Domestication," led him to believe rather 
more in the direct action of physical conditions, though he seemed 
to regret it because it lessened the glory of natural selection and, 
to use his own language, "is so confoundedly doubtful." One can 
plainly trace from the correspondence how, prior to the publication 
of the "Origin," he more and more, as his facts accumulated, and 
as the theory of natural selection grew upon him, relegated to an 
inferior place the influence of environment; while, subsequent to 
the publication of that work, and up to the time of his death, the 
tendency seemed to be in the opposite direction. 
Many eminent workers have differed greatly from Darwin in the 
influence allowed to these external conditions, and this is particu- 
larly the case with our American writers. Indeed, no one can well 
study organic life, especially in its lower manifestations, without 
being impressed with the great power of the environment. Joseph 
LeConte speaks of the organic kingdom lying, as it were, "passive 
and plastic in the moulding hands of the environment." Leidy, 18 
SECTION F. 
Wyman, Clark, Packard, etc., have insisted on the influence of 
physical conditions. Baird and Ridgway on geographical distribu- 
tion, Whitman on concrescence, Hyatt on gravitation, Cope and 
Ryder on mechanical stress, have all published valuable corrobora- 
tive evidence ; while many other writers have added their views 
and testimony which have been admirably condensed by Professor 
Morse in two addresses before this Association. Allen demon- 
strates plainly the influence of climate and temperature in directly 
inducing specific changes. Weismann, in his remarkable "Studien 
der Descendenz Theorie," concludes that differences of specific 
value can originate only through the direct action of external con- 
ditions, and that allied species and genera, and even entire families, 
are modified in the same direction by similar external inducing 
causes. In Semper's "Animal Life" (1877) we have the best sys- 
tematized effort to bring together the direct causes of variation, and 
no one who has read through its pages can doubt the direct modi- 
fying influences of nutrition, light, temperature, water at rest and 
in motion, atmosphere still or in motion, etc., or question his con- 
clusion that no power which is able to act only as a selective and 
not as a transforming influence, can ever be exclusively put forth 
as a causa efficiens of the phenomena. Kolliker, in 1872, wrote: 
"Manifold external conditions, when they operate on eggs under- 
going their normal development, on larvae or other early stages of 
animals, and on the adult forms, have produced in them partly pro- 
gressive, and partly regressive, transformations," and recognized 
as most important forces, nutrition, light and heat. Indeed, the 
direct action of environment must have been, as Spencei* puts it, 
"the primordial factor of organic evolution." 
In so far as it offers evidence, entomology confirms the conclu- 
sions of the writers in other departments of natural history, above 
referred to, and offers a host of most conclusive proofs of the di- 
rect action of the physical and chemical factors which I have enum- 
erated. Justice, however, could not be done to the facts within 
the limits of an address of this kind, and I pass on to some of the 
other factors. 
It is among what I have called the vital or organic conditions 
of variation that natural selection has fullest sway, and as they 
have been so ably expounded by Darwin and others they may be 
dealt with in few words. 
Interaction of Organisms.-The productions, as a whole, of greater ADDRESS BY C. V. RILEY. 
19 
areas will, whenever they get an opportunity, conquer those of 
lesser areas, and in this broad sense, the interaction of organisms 
may be said to have had no special modifying power, however great 
its influence may have been, and is yet, in inducing the survival of 
the fittest, or in bringing about the present geographical distribu- 
tion of species. The consequence of enforced migration and of 
isolation are best considered when dealing with the physical con- 
ditions, because they must influence modification of masses rather 
than of individuals, and either substitute one type for another or 
remove competing or differentiating influences. But in the more 
restricted sense, i. e., the interaction of organisms occupying the 
same ground-the struggle for existence, in other words, between 
direct competing organisms-is a prime Darwinian factor of mod- 
ification, and a whole volume of illustrations may be drawn from 
entomology ; for in no class is the contest more severe, whether with 
plants, or with other animals, or with one another, than in insects. 
In no other field of biology, for instance, have the physical condi- 
tions resulted in such infinite diversity of form and habit fitted, 
whether for earth, air or water, and often for all in the same indi- 
vidual ; so, also, in no other field, is parasitism carried to such a 
degree, or are the purely adaptive structures due to this interac- 
tion so varied or so remarkable. The entomologist who goes be- 
yond the "dry bones" of his science is inevitably a Darwinian. 
In this category must also be included that interrelation between 
insects and plants which has eventuated in the so-called carniv- 
orous plants, and that still more wonderful interaction between 
flowers and insects by which each has modified the other, and the 
facts of which have been so untiringly observed and so well set 
forth by a number of writers from Sprengel's day to this, and by 
none more successfully than by Darwin himself. These are plainly 
inexplicable on external conditions acting on masses alike and are 
meaningless enigmas except on the theory of natural selection, or 
some supra-natural and dogmatic gospel. 
We are thus led, through this last, from the external to the in- 
ternal factors in evolution, or those of a physiological and psychi- 
cal nature. In these, natural selection is the key which, so far, 
best unlocks their meaning and shows how they have acted in the 
formation of species and the less fundamental of the great groups. 
In considering them it is hardly necessary to discuss their relative 
importance as compared with the external conditions, though it 20 
SECTION F. 
may be remarked that they are the factors which have induced the 
great variety of adaptive forms and minor differentiations, while 
the external conditions have governed the formation of the great 
and more comprehensive types of structure. 
Darwin was led to give more importance toward the end than he 
had originally done, to some of these internal factors and especially 
to functionally-produced modifications. In the "Descent of Man" 
he says that he did not sufficiently consider variations "which so 
far as we can at present judge are neither of benefit nor injurious ; 
and this I believe to be one of the greatest oversights I have yet 
detected in my work." And in the sixth edition of the "Origin" 
he frankly admits that he had omitted in other editions to consider 
properly the frequency and importance of modifications due to 
spontaneous variability. He further refers to morphologic differ- 
ences, which may have become constant through the nature of the 
organism and the surrounding conditions rather than through nat- 
ural selection, since they do not affect the welfare of the species. 
In short, Darwin's views kept pace with the investigations of his 
day and tended in the direction of restricting rather than widen- 
ing the influence of natural selection. But, as Romanes, and es- 
pecially Spencer, in his Factors of Evolution, have fully shown 
Darwin's position on this subject, I may pass over the detail. 
Internal Conditions-Physiological.- Genesis itself is the first 
and most fundamental of all causes of variation. The philosophy 
of sex may, indeed, be sought in this differentiation, as the accu- 
mulated qualities in separate entities when suddenly conjoined or 
commingled inevitably lead to aggregation and heterogeneity-in 
other words, to plasticity or capacity to vary. Genesis, as a fun- 
damental factor in evolution, may be more intelligently considered 
under some of its subordinate phases, as heredity, physiological se- 
lection, sexual selection, primogenital selection, sexual differentia- 
tion including philoprogeneity, hybridity, etc. 
Heredity, as expounded by the ablest biologists and as exempli- 
fied in life, is a puissant factor in evolution and though essentially 
conservative must, through the marvellous power of atavism, tend 
to increase individual variability. The subject has been too well 
considered by Darwin and his followers to justify further discussion 
of it here. As a cause of variation, heredity must, however, have 
less and less influence as we go back in the scale of organized be- 
ings ; for it cannot well come into play in agamic or fissiparous re- ADDRESS BY C. V. RILEY. 
21 
production, a fact which has given the abiogenesists one of their 
strongest arguments, since it is difficult to understand how, for in- 
stance, the monera of to-day could have descended without change 
from the primordial form. 
Physiological Selection.-Physiological selection, as suggested 
by Mr. Catchpool and as expounded by Romanes, is undoubtedly a 
veritable factor in evolution, and while giving us another link in 
the chain of evidence as to the causes of differentiation, lessens in 
but very slight degree, the overwhelming force of the argument for 
natural selection. It adds, rather, an important element in the 
evidence therefor and may be classed as a subordinate cause of 
differentiation. Romanes' theory is based upon the argument that 
differences, such as constitute varieties and species in their com- 
mencement, would not be preserved by natural selection unless 
useful, but would be lost again by cross breeding with forms like 
the parent, and which had not varied, except upon some hypothesis 
like that of physiological selection. This could not be prevented 
except by migration. This difficulty is a general one, was argued 
by Darwin himself, and has been felt by all Darwinians. The re- 
productive organs are extremely variable and sterility may occur 
not only between species, but between races and varieties and often 
between individuals. Physiological selection tends to form varie- 
ties by peculiarities in the reproductive system of individuals which 
render them unfit for perfect coition, or cause them td remain more 
or less sterile, with other individuals which have not the same 
peculiarities. 
The exact reasons are recondite, and the whole subject difficult 
of demonstration except from the results, since changes in the re- 
productive organs are not easily observable. Romanes believes 
this sterility to be incidental to variation and hence one of the chief 
causes of the accumulation of such variation. Wherever there has 
been modification of the reproductive organs introducing incompat- 
ibility between two individuals, even where there has been no other 
change or variation, we have a valid cause of differentiation which 
in its consequences must be important. Compatibility or fertility 
between individuals is of the very essence of selection. Natural 
selection implies that this sexual divergence is subsequent to or co- 
incident with divergences in other directions ; physiological selection, 
that it antecedes them. To put the case of Romanes more fully, 
we will suppose that among the natural variations there occasionally 22 
SECTION F. 
occurs something to affect the reproductive organs in such wise as 
to produce incompatibility, i. e., incapacity of one individual with 
another of the parent type, to unite, or sterility of such union, while 
it remains fertile with the variation of its own kind. This theory 
of course implies variation in the reproductive organs, or depart- 
ure from the parental type, in at least two individuals of opposite 
sex simultaneously, and with this admission, for which we are jus- 
tified in facts, physiological selection will preserve many peculiar- 
ities which need have no necessary connection with the exigencies 
of life. 
The change may be in the organs of reproduction, introducing 
sexual incompatibility, or it may be due to other causes, as, for in- 
stance, the time of flowering in plants, or the season of heat in an- 
imals. Even the element of scent becomes important here, as my 
friend J. Jenner Weir has suggested, since it may influence sexual 
relationship, so that the very excretions of the body, which vary 
with individuals, must be allowed their part. Francis Galton has 
indicated a modification of Romanes' views, viz., that the prima- 
ry characteristic of a variety resides in the fact that the individ- 
uals who compose it do not care to mate with those outside their 
pale. Incipient varieties are thus thrown off from the parent stock 
by means of peculiarities of sexual instinct which prompt what 
anthropologists call endogamy and check exogamy or marriage 
without the tribe or cast. This is a very good anthropological il- 
lustration of how physiological selection may begin. 
Natural selection preserves the individuals best adapted to life con- 
ditions by destroying the less fit. Physiological selection may be 
said to preserve differences which have no necessary connection 
with the necessities of life. Neither touches the origin of the va- 
riation, but both express laws thereof or methods by which it is 
accumulated. The inherent tendency to vary, whether in external 
or adaptive structure, or internal or reproductive character, is sim- 
ply an observed fact, the causes of which we are endeavoring to 
analyze. 
Physiological selection is remarkably exemplified in insects and 
probably in no other class are the modifications which may be at- 
tributed to it more easily studied ; for in no other class are the 
genitalia of the male so variable or so complex. There has so far 
been no attempt to homologize the different parts in the different 
orders of insects, so that they have received different names ac- ADDRESS BY C. V. RILEY. 
23 
cording to individual authors. Ordinarily there are two pairs of 
claspers, themselves very variable, associated with sundry hooks 
and tufts of hair. There are families, as in the Cecidomyidse, among 
the Diptera, in which many species are almost, and others, abso- 
lutely, indistinguishable except by the differences in the male geni- 
talia. In all other orders there are an immense number of forms 
which can only be distinguished by a careful study of those organs. 
Descriptive entomology to-day, which does not take account of 
these organs, is, in fact, almost valueless, and we must necessarily 
assume that where there is differentiation of structure in these im- 
portant parts it implies a corresponding modification on the part 
of some associated female even where no other differentiated char- 
acters are to be detected, and upon Romanes' law such must be 
looked upon as physiological varieties and will be counted good 
species in proportion as the differentiation involves other observ- 
able characters or as their life habits determine. 
Sexual Selection.-The part of sexual selection in inducing 
variation may next be considered. While it is evidently at the 
bottom of the diversity in sex so common among many animals, it 
is difficult to see how it can play any very important part in the 
differentiation of species, except on the hypothesis that the greater 
the differentiation between the sexes the greater the tendency to 
vary in the offspring. In no class of organisms is this factor 
more notable than in insects, and volumes might be written to re- 
cord the interesting and curious facts in this class alone. As a gen- 
eral rule it may be said that with insects, as with other animals, 
it acts chiefly in inducing secondary sexual characteristics in the 
male, and in simplifying the characteristics of the female. Nowhere 
do we find greater contrasts between the sexes, involving almost 
every organ, both colorationally and structurally. Where color 
is affected, the greater brilliancy almost always belongs to the male 
sex, as in birds. So where song or sound is employed to attract, 
the sound organs are either peculiar to, or most highly developed 
in, the males. As in higher animals, also, so in insects, we find 
offensive organs highly developed in the male, and either lacking, 
or but partially developed in the female, wherever the struggle for 
the possession of the female is by force, or strength. It has evolved 
scent organs in various parts of the body, causing modification, 
especially in the Lepidoptera, of either the membrane of the wing, 
or the scaly covering ; it has induced profound modification in the 24 
SECTION F. 
structure of the legs, whether the anterior, middle or posterior pair, 
and whether in the whole member or some part of it, or in its 
covering. The subject has been so fully treated by Darwin, how- 
ever, that it is not necessary to elaborate it further in this connec- 
tion. Strictly speaking, it may be said to act in two ways, viz.: 
by conflict of the males for possession of the female, or by attract- 
iveness, the former being most conspicuous among mammals, the 
latter among birds, and both coming conspicuously into play among 
insects. It is rather difficult to define the limit of sexual selection 
as a factor in evolution, but 1 would not confound it with another 
factor, not hitherto generally recognized, but which I think must 
be all-powerful, namely, sexual differentiation. 
Sexual Differentiation.-It seems evident that the mere differen- 
tiation of sex in itself has been an important element in variation. 
The principle elaborated by Brooks as a modification of the theory 
of pangenesis is a good one, and in the main the male may be said 
to be the more complex and to represent the progressive, and the 
female the more simple and to represent the conservative element in 
nature. When the conditions of life are favorable, the female pre- 
ponderates, and exercises a conservative influence. When the con- 
ditions are unfavorable the males preponderate and with their 
greater tendency to vary induce greater plasticity in the species, 
and hence greater power of adaptation. Sexual differentiation may, 
I think, be used to include many other variations and differentia- 
tions not otherwise satisfactorily accounted for, and to express the 
law of the interaction of the sexes upon one another, inducing great 
differentiation entirely apart from the struggle of the males for the 
possession of the females, or the struggle for existence. Among 
insects, particularly, though the same is true among other classes, 
we find many illustrations of this that can hardly be explained by 
the other forms of selection. 
A few of the more notable in Hexapods may be instanced, as 
the degraded form of the female in Stylopidae; in very many Lepi- 
doptera and Coleoptera ; in the females of the Coccidae, in Homop- 
tera, etc. In most of these cases it is the female which has been 
modified, without any very special modification in the male, though 
it is a general rule that in proportion as the female is degradational 
and stationary, the organs which permit him to find her, or to mate 
with her, and particularly the antennae, eyes and genitalia are pro- 
foundly modified and complex. This is especially noticeable in ADDRESS BY C. V. RILEY. 
25 
the Psychidae where the female remains in her case, a mere mouth- 
less, eyeless, legless and wingless grub, and the male has most com- 
plex and ramose antennae and complex genitalia. Another remark- 
able instance may be cited in the Lampyridae, where we find every 
degree of degradation in the female, from partial wings to no wings 
at all, accompanied with increasing complexity of eyes and anten- 
nae in the male, until at last in the Phengodini the female is so lar- 
viform that she can hardly be distinguished from the true larva. 
In all these cases the female has been as profoundly modified as, 
and often more so than, the male, and in the latter case a phos- 
phorescent power has been evolved so that the attractiveness, as 
in the human species, is rather on the female side. Again, in the 
case of Corydalus, in Neuroptera, the profound modification of the 
jaws in the male into prehensile sickle-shaped organs is to be ex- 
plained rather on the interaction between the sexes, and the facil- 
ity the modification offers for coition, than upon sexual selection 
in its proper and restricted sense. 
In this category must also be included the influence of philo- 
progeneity which has modified the female rather than the male either 
in the primary sexual organs for offence or defence, as in the sting 
of the aculeate Hymenoptera; or in the secondary sexual charac- 
ters, as in the anal tufts of hair, secretory glands, etc., of many 
Lepidoptera ; or in modification of various other parts of the body 
exhibited in various orders of insects to facilitate provision for 
their young, whether in the preservation of the eggs or the accu- 
mulation of food for the future progeny. A notable instance of 
how far this may be carried is furnished by the female Pronuba, 
where the ovipositor and the maxillfe are so profoundly modified 
as to make her unique in her order. Sexual selection can have lit- 
tle to do with these modifications, cases of which might be multi- 
plied indefinitely ; nor can they be fully explained by natural 
selection, in the restricted sense in which we have proposed to use 
it; nor by physiological selection. 
In this category might also be included modification which has 
resulted in the various forms of females which obtain in the same 
species, fitted whether for agamic or sexual reproduction and which 
are far more readily explained on the theory of sexual differentia- 
tion aided by environmental influence, especially food and temper- 
ature, than upon any other. 
Hybridity.-The subject of hybridity has been fully discussed 
by many and by no one more ably than by Darwin himself. It 26 
SECTION F. 
has generally been assumed that the hybrid of any two species is 
sterile, and, in fact, hybridity has been looked upon as one of the 
best tests of specific value next to genesic incapacity. The as- 
sumption finds its greatest support in genesis among the higher 
animals, and the most thoroughly differentiated species; but the 
whole subject becomes complicated as we descend in the organic 
scale, and hybrids between what naturalists generally separate as 
good species are far more frequently fertile among plants and lower 
animals than was formerly supposed ; while physiological selection, 
as we have just seen, may render genesis impossible, or at least 
prevent it, between varieties and incipient species. In this light, 
hybridity becomes an important factor in the modification of spe- 
cies. Unnecessary importance has been given, in my judgment, 
to the fact that domestic and wild species differ in the fertility of 
their crosses. It is assumed, for instance, all the known 
breeds of domestic dogs would be fertile inter se'and produce fer- 
tile crosses. It seems to me, on the very face, a preposterous 
proposition and that many of the breeds of domestic dogs are as 
distinct specifically, and even generically, so far as this test is 
concerned, as they are in structure and other characteristics. Who, 
for instance, has ever known or heard of a cross between a bull 
dog and a lap dog, or between a Newfoundland and a black and 
tan? The difference in size alone would seem to render such a 
cross, if not a physiological or a physical, at least a practical, im- 
possibility ; so that hybridity among domestic animals tends to 
essentially the same result as among wild animals, and confirms its 
importance as a differentiating factor. 
Having thus summarily indicated those factors of evolution as- 
sociated with genesis and which are essentially physiological, how- 
ever much psychical phenomena may cooperate, we may touch upon 
the more purely psychical factors or those pertaining to the growth 
and use of mind, employing the term to express those neural phe- 
nomena traceable to the medium of the brain. Their importance in 
evolution increases with increasing cephalization and complexity 
of nerve system. For the present purpose, however, it is with the 
objective side of psychology or what may be called psycho-physi- 
ology that we must deal. 
Psychical-Use and Disuse.-Full consideration of the effect of 
use and disuse involves a discussion, not only of the question of 
the transmission of acquired structures, but of the influence of in- 
dividual effort and of necessity, i. e., a consideration of the essen- ADDRESS^BY C. V. RILEY. 
27 
tially Lamarckian factors in evolution. The occasion will not 
permit me to do full justice to these subjects. That functionally- 
produced modifications are inherited was the great assumption 
upon which Lamarck founded his theory of evolution. Many able 
naturalists have insisted on it, and in my judgment there should 
no longer be any doubt whatever of the fact, not only so far as 
grosser structure is concerned, but brain structure likewise. No 
question is of more moment in the whole range of biology and es- 
pecially biologic philosophy, and Spencer has well pointed out that 
on the answer to it will depend largely the sciences of psychology, 
ethics and sociology. Weismann, Lankester and others deny hered- 
itary power in such modifications, the former believing that heredi- 
tary modification can result only from changes in the germ plasma, 
i. e., are virtually congenital. Natural selection, according to this 
view, plays upon the germ plasma; but I have never been quite 
able to comprehend how this view, even if established, militates 
against the transmissibility of acquired modification, for, whatever 
theory of heredity we adopt, it shows us rather the manner of the 
transmission and therefore confirms its possibility. But the fact 
of such transmissibility rests neither on embryological nor theo- 
retical grounds. It is a fact so fully demonstrated in the history 
of our domestic animals and the history of agriculture, that the 
skepticism of some of our great naturalists and embryologists must 
be attributed to that ignorance of the farmers' commonest experi- 
ences which is, unfortunately, a too frequent attribute of the city- 
trained investigator. Darwin in the beginning, and while the 
importance of natural selection was growing in his mind, allowed 
little importance to use and disuse for the same reason that he sub- 
ordinated external agencies; viz., that, in proportion as it acts on 
masses simultaneously, it must diminish the importance of natural 
selection. Yet he allowed more weight to it toward the end and 
has furnished some of the best evidence drawn from domestic ani- 
mals of the transmission of acquired characters, affecting the der- 
mal, muscular, osseous and nervous systems. Spencer has shown 
that inheritance of functional modification is most easily observed 
and experimentally proved in those parts which admit of easy ob- 
servation and comparison, as the dermal covering and the bones; 
and that they for the most part are beyond these tests in the mus- 
cular and nervous systems. Yet he logically concludes: 
"Considering that unquestionably the modification of structure 
by function is a vera causa, in so far as concerns the individual; 28 
SECTION F. 
and considering the number of facts which so competent an ob- 
server as Mr. Darwin regarded as evidence that transmission of such 
modifications takes place in particular cases ; the hypothesis that 
such transmission takes place in conformity with a general law, 
holding of all active structures, should, I think, be regarded as at 
least a good working hypothesis." 
So far as Entomology bears evidence, it confirms the fact that 
modifications of structure due to use or disuse on the part of the 
individual may be and are transmitted. These are easily observed 
in the exo-skeleton, and while the experimental proof is yet limited, 
it is not wanting, especially in the history of apiculture. Excessive 
use of any organ will develop or enlarge it at the expense of other 
organs, just as disuse will cause a diminution, or atrophy thereof. 
The variation in the individual will be within limits, but when once 
the variation has set in, the tendency is always to an increased va- 
riation in the same direction in the descendants, especially if they 
continue the same use or disuse. Here, again, however, it is diffi- 
cult to separate the modification due to individual effort, or want 
of effort, and the more general modification affecting the mass of 
individuals of a species through the environment; because the en- 
vironment affects function, and function in its turn affects form and 
structure. The life of every individual furnishes an excellent il- 
lustration of new action and new uses for organs not previously 
used, in the striking and sudden employment of postnatal organs, 
both of respiration and nourishment, which pre-natally had no cor- 
responding action. Romanes has argued that Cessation of Selection 
may reduce an organ where use or disuse can have no play, as in 
the loss of wings in neuter ants ; and that by the law of compensa- 
tion an organ may even be increased, as in the heads of such neu- 
ters. He enforces the idea by exampling the blind crabs of our 
Kentucky caves, where the complex eyes rapidly disappear under 
cessation of selection, but where the persistence of the foot-stalks 
indicates that economy of nutrition could have had little play ! It 
is difficult, however, to draw the line between this cause and Lan- 
kester's reversal of natural selection ; and still more difficult to say 
wherein either differs from mere disuse. 
Degeneration which has been urged as the true explanation of 
many of the existing forms of life is, it seems to me, but a con- 
sequence of disuse and would therefore fall into the present cate- 
gory, among causes of variation. 
Emotion as affecting the Individual.-I have here considered the ADDRESS BY C. V. RILEY. 
29 
factor of use and disuse as a direct cause of variation, from the 
psychical rather than the physical standpoint, i. e., individual or 
conscious effort as furnishing food for natural selection, among 
more highly endowed animals, rather than as effort by species as a 
whole necessitated by physical conditions and inducing modifica- 
tion in masses irrespective of selection. This leads us to the con- 
sideration of mind as a factor in evolution, and we shall soon see 
its importance as a fundamental cause of differentiation, among 
higher organisms at least. I am not sure, even, that its influence can 
be excluded from among lower animals, however much we may have 
to exclude its action in so far as plants are concerned ; for any new 
functional effort inducing new use may be looked upon as conscious 
and intelligent as compared with use fixed by habit and lapsed into 
automatic action or instinct. The former typifies variability and 
progress ; the latter constancy and stability. 
Mind is a comprehensive cause of variation and may be consid- 
ered under several categories : We have, for instance, (1) the ac- 
tion of the mind of the individual in willing, or in selecting between 
differing alternatives that present themselves, as in the choice of 
means to ends ; (2) the direct influence of the emotions on the in- 
dividual ; and (3) the influence of the emotions of the pregnant 
mother on her offspring. 
In the first category the influence of mind in modifying is chiefly 
confined to man. It must have acted from the time when he first 
began to prepare his crude weapons of defence and offence to the 
present day, when some new discovery or some new invention may 
alter the map of the world, revolutionize society, or give one race 
or nation the advantage over another; nor can we feel sure that 
animals below man have not been modified by similar psychical ef- 
fort. In the second category, the direct influence of the emotions 
on the individual, it is a psycho-physiological factor involved in the 
question of use and disuse; for if it be once admitted (and I think 
the tendency of modern neural science is in the direction of estab- 
lishing the fact) that strong mental effort may be made to affect 
special parts of the body, i. e., that an excess of nervous force 
brought to play on any particular organ or any particular part of 
the organism, induces increased growth or development of such 
parts ; we can understand how far desire, especially under the spur 
of necessity, may be influential in inducing modification. Lamarck's 
idea, therefore, may not be so ridiculous as it has hitherto been 30 
SECTION F. 
supposed by many. Darwin took no stock in this influence, and 
referred with some contempt to the views of Lamarck, and Geoffroy- 
St. Hilaire. He thought it strange that the author of " Les Ani- 
maux sans Vertebres " should have written that insects which never 
saw their eggs should will them to be of particular form, which he 
thought hardly less absurd than to believe that the desire to climb 
should make a Pediculus formed to climb hair, or a woodpecker to 
climb trees. 
Emotion of Mother as affecting Offspring.-There may be some 
doubt about the extent of the influence of the individual mind in in- 
ducing direct modification, for the subject is a difficult one to deal 
with and we have few exact data to draw from. Since in human 
affairs we recognize the power of will in affecting purpose and ac- 
tion and in mouldingcharacter, it is legitimate to infer that when our 
knowledge has increased we shall recognize its effect on function. 
There can be less doubt as to the third category, viz., influence of 
the mind or emotions of the pregnant mother, on her offspring in 
inducing modification both physiological and mental. As a cause 
of variation, though believed in by J. D. Hooker, as we learn from 
the "Life and Letters," and by other of Darwin's contemporaries, 
it was discarded by Darwin himself, his principal reasons being 
that the results of observations made for him in hospitals were 
adverse to any such influence. Medical men, as a rule, also dis- 
card it as among the mere notions and superstitions of women, 
and argue its impossibility on the ground that there is no neural 
connection between mother and foetus. The ancients practically 
recognized the influence of the imagination of the mother on her 
offspring, and belief in it is still very prevalent among women them- 
selves, of all classes. Women alone are able to speak or feel in 
this matter, from experience, and the almost universal belief in the 
influence, among those who have any experience at all, should make 
us hesitate to discard it too summarily. From facts within my 
own personal knowledge 1 have long believed in this influence, and 
the more I have been able to collect reliable data bearing upon it, 
the more confirmed have I become in the conclusion that the emo- 
tional experiences of the mother affect the issue in varying degree, 
according to the intensity of the emotion. When sudden and ex- 
cessive as in rage, fright, repugnance, etc., or where prolonged or 
accumulative, as in continued brooding, it may induce nervous 
disorders and even mental aberration, idiocy or insanity ; or, again, ADDRESS BY C. V. RILEY. 
31 
physiological change, as atrophy or increase of parts, and other pe- 
culiarities which haverelation to the form or character of the induc- 
ing mental manifestation or shock in the parent. Investigation of 
this, as of all subtle phenomena, is attended with the difficulty of 
separating the chaff of fancy from the grain of reality. The method 
pursued by Darwin is unsatisfactory, as it dealt with normal con- 
ditions which furnish no evidence and with the fanciful or notional 
side of the subject. The literature of the subject is extensive and 
quite interesting, and I would refer particularly to the work and 
writings of Viellard, Schoenfeld, Demangeon, Lucas, Fere and 
Brown-Sequard. Two other difficulties confront the investigator : 
first, the somewhat unsatisfactory state of neurology and the diffi- 
culty of experimental research therein, as indicated by Vice Presi- 
dent Bowditch before this section two years ago ; secondly, the aver- 
sion, from feelings of delicacy, on the part of the persons concerned, 
to publicity of the more marked and striking evidence. The phe- 
nomena of hypnotism, proving as they do that physiological re- 
sults may be induced through the imagination of the subject acted 
on by the mind of the hypnotizer, are suggestive in this connection, 
the work of Charcot in Paris more particularly showing how pow- 
erful the action may be and how the effects of actual medicines may 
be produced by the use of imagined ones. The mind of the hyp- 
notized under these conditions is brought into those exceptional 
and exalted conditions which are necessary in the case of the 
mother to produce on her offspring the effect which we are discuss- 
ing. The recent experiments of Mr. C. T. Hodge on the effects 
of stimulation on the nucleus and cell-body and on protoplasm are 
also interesting here showing, as they do, decrease in the two former 
and vacuolation of the latter as the result. 
The history of science is present to tell us that common and per- 
sistent belief, based on experience, has not infrequently been met 
with skepticism and even ridicule on the part of scientific men, 
only to be vindicated finally by more thorough and exact knowl- 
edge. It is too often the case that, where the processes are recon- 
dite and difficult to follow, assumption passes for knowledge. The 
function of some of our own bodily organs yet remains to be es- 
tablished and we probably assume too much in requiring that all 
nervous force must be transferred through nerve tissue, or that 
there may not be protoplasmic filaments which are not resolvable, 
in their finer ramifications, even with our best microscopes. The 32 
SECTION F. 
very nature of mind and its processes puts it beyond the reach of 
the scalpel of the anatomist or the physiologist, just as many psy- 
chical phenomena baffle the exact methods of science, at least those 
so far employed. Leaving out of the question the evidence of 
peculiar marks due to maternal emotion, cases of which are part 
of the unwritten history of almost every family, the striking cases 
of which I have authoritative evidence of addition to, subtraction 
from, or singular modification of, anatomical parts, confirm me in 
the belief that this is a most important psycho-physiological cause 
of modification. 
In the romance of Elsie Venner, in which the heroine's strange at- 
tributes are connected with pre-natal influence of the mother, who 
died of the bite of Crotalus, Oliver Wendell Holmes has strongly 
put forth this doctrine in the form of fiction. I allude to this clever 
romance because of the medical knowledge of the eminent author, 
and because while admitting in the preface that a grave scientific 
doctrine lies beneath some of the delineations of character, he 
also affirms that he has had the most startling confirmation of its 
truth. The data collected on the subject I hope to bring together 
on some other more fit occasion, and I would take this opportunity 
of urging any in my hearing or who may read these lines, if they 
have had or are aware of any authoritative and illustrative cases, 
to communicate them to me with as much detail as possible. 
This theory once established, its bearing on evolution as a prime 
cause of variation must at once be manifest; for it gives not only 
tangibility to the Lamarckian idea of desire influencing modification, 
but, also, a conception of how Infinite Mind in nature may act 
through the finite in directing such modification. No doubt but that 
there is a great deal of nonsense and superstition mixed with the 
genuine, and that the idea that every little whim, or fancy, or im- 
agining of the mother will produce record, or mark, is one of the 
unjustified outcroppings of the fundamental fact, and helps to ex- 
plain the difficulty of getting at the real facts and the ease with 
which Darwin rejected the idea. In my judgment this factor acts 
only when, from whatever cause, and particularly under the spur of 
necessity, the emotions are exceptionally intensified, or the desire 
strongly centred in some particular object. The conception is per- 
fectly legitimate, for instance, that when a species is subjected to 
any external modifying cause, affecting all its members alike, the 
adaptive modifications which natural selection, under such circum- ADDRESS BY C. V. RILEY. 
33 
stances would play upon, have their origin in the emotions, or the 
influences at work on the pregnant females, giving direction in their 
offspring, to the needed changes. In this way it is probable that 
only those individuals born under such conditions would be able to 
survive. Thus this becomes no mere ancillary cause of variation 
but one of deepest import and at the very foundation of evolution. 
The female in this light acquires an increased importance, and evo- 
lution finds her not only the essential at the dawn of life upon our 
planet, but, in its present highest manifestations she is nearest by 
instinct, intuition and aspiration to the Controlling Mind, which 
in the beginning quickened the great womb of nature and down 
through all the ages guided the continuous stream of life to designed 
ends through the individual womb of the mother. 
As already remarked, the psychical factors which we have been 
considering are substantially Lamarckian, and in proportion as we 
consider them and get to understand the other direct causes of 
variation, must we give importance to the ideas of Lamarck and, 
conversely, less importance to the ideas of Darwin. 
Did time permit I should like to go into an analysis of Lamarck's 
"Philosophic zoologique" and show how the genius of this illus- 
trious French naturalist anticipated a very large part of that which 
Darwin subsequently so laboriously helped to establish. I must 
pass the subject, however, and simply record my surprise that one 
who was otherwise so honest and fair toward other writers was so 
evidently unfair in his estimate of the work of Lamarck, as Darwin, 
in the " Life and Letters," is shown to have been. It is incom- 
prehensible, reading Lamarck with our present knowledge, that 
Darwin should have found neither fact nor ideas in a book which 
abounds in both, except on the theory of a poor translation or that 
strange national antipathy which has so often prevented the people 
of one country from doing justice to those of the other, and which 
so long prejudiced the French Academy against Darwin's own es- 
pecial theories. 
Darwinism assumes essential ignorance of the causes of variation 
and is based on the inherent tendency thereto in the offspring. 
Lamarckism, on the contrary, recognizes in use and disuse, desire 
and the physical environment, immediate causes of variation affect- 
ing the individual and transmitted to the offspring in which it may 
be intensified again both by inheritance and further individual 
modification. Both represent important principles in evolution and 34 
SECTION F 
cooperate to bring about the results. The theory I propose gives 
renewed importance to the Lamarckian factors by showing one 
manner of their action not previously urged and it also helps us to 
a tangible and scientific conception of design. 
Acceleration and Retardation.-In this rapid glance at the imme- 
diate causes of variation we have discussed some factors which, in 
some degree, represent laws rather than inducing causes of varia- 
tion. This difficulty appertains to all attempts at formulation of 
the causes of variation, and only as our actual knowledge increases 
shall we be able succinctly and definitely to classify the factors. 
There are, however, certain important laws which have influenced 
modification but in no sense can be looked upon as causes of va- 
riation. They are laws or principles of evolution by which we may 
account for the formation of types, acting, just as natural selec- 
tion does, in differentiating rather than in originating the variation. 
No one can have followed the important and suggestive works of 
Cope and Hyatt on the subject of acceleration and retardation and 
not feel that it expresses an important law of this kind. It is, as 
I understand it, a factor in evolution not comparable with the prin- 
ciple of natural selection, but complementary thereto, much in the 
same way as physiological selection and sexual selection are. It 
is an attempt to give expression and form to a set of facts to which 
palaeontology undoubtedly points and which ontogeny substan- 
tiates, viz., that certain types may attain perfection in time and 
then retrogress and finally become extinct, and that existing types 
which are dying out, or degenerating, exhibit, ontogenically, the 
culmination of force and complexity, followed by decadence, cor- 
responding to the phylogenic history of the type. We know, 
from the " Life and Letters," that Darwin gave up in despair the 
attempt to grasp the full meaning of these particular views of our 
associates, and in a letter to Hyatt, with characteristic modesty, 
he attributes this inability to his own dulness rather than to any 
weakness in the theory. Others have experienced the same diffi- 
culty and believe, with Professor Morse, that the facts enumerated, 
as well as the facts of exact and inexact parallelism are explicable 
on the doctrine of natural selection. This is true, it seems to me, 
only on the broader, unjustified interpretation of the doctrine to 
which I have previously alluded in the opening of these remarks. 
The law of acceleration and retardation may, perhaps, be substan- 
tially stated in this wise : that certain groups acquire some charac- ADDRESS BY C. V. RILEY. 
35 
ters rapidly, while corresponding groups acquire the same charac- 
ters more slowly, or never acquire them at all, and this brings us to 
another important factor of evolution which serves to give force to 
the law. 
Acceleration by Primogeniture.-This has been elaborated by 
Hubrecht. He argues that so long as the parent form remained 
most in harmony with the surrounding conditions it would main- 
tain in the struggle for existence its characteristics against all ten- 
dency to vary in its offspring ; which is equivalent to saying that 
it will remain unchanged so long as the environment remains the 
same. He then shows that in organisms in which the reproductive 
period covers many years, accelerated development by primogeni- 
ture, i. e., as between the first born and the last born of any pair 
and of their posterity, will, in time, produce differentiation. The 
series of the first born will, in the course of time, involve many gen- 
erations at short distances from each other, whereas, the series of 
the last born will, on the contrary, consist of a much smaller num- 
ber of terms each separated from its predecessor by a more con- 
siderable distance. Any tendency to variation from external or in- 
ternal influences must needs find more numerous occasions to act 
in the series of the first born, not only because these have a more 
composite ancestry but because they necessarily become the most 
numerous. In other words, the chances are more numerous for 
small differences among the first born series, and in proportion as 
such differences are accumulated, intercrossing and bastardizing 
with the series of the last born will become rarer. This law will 
gain from physiological selection and, it seems to me, throws addi- 
tional light on that of acceleration and retardation. It must act more 
particularly among higher animals where the reproductive period 
is lengthened and the time between the first and last born is great. 
Saltation.-We are thus led to what have been called saltations 
in evolution. Although the history of palaeontology has contin- 
ually added to our knowledge of past forms, and helped to fill up 
many gaps in the evolutional series, and although, during the last 
quarter of a century, it has particularly vindicated Darwin's proph- 
ecy that many links would yet be found, the substantial truth 
remains that gaps still occur, and that progress, so far as present 
knowledge indicates, has been made by occasional saltations. 
There have been, it would seem, periods of rapid movement, and 
of comparative repose, or readjustment of equilibrium. Cope con- 36 
SECTION F. 
eludes that, "genera and higher categories have appeared in geo- 
logic history by more or less abrupt transitions or expression points, 
rather than by uniform gradual successions." 
One of Pictet's strongest points, in opposition to Darwin's the- 
ory, which struck Darwin himself with much force, was that it 
ill agreed with the history of organisms with well marked and de- 
fined forms, which seem to have existed during but a limited period, 
as for instance, the flying reptiles, the Ichthyosaurs, Belemnites, 
Ammonites, etc. Some authors, who have fully recognized these 
gaps or leaps in the developmental history of animals, yet believe 
them to be consistent with the theory of gradual modification. It 
may be only one individual of many which becomes modified and 
transmits the modification to descendants: it may be but one spe- 
cies of a genus which, for similar reasons, supersedes the rest which 
become extinct in time proportioned to prolificacy. 
There is no reason to suppose that the history of organic life has 
differed in this respect from that of inorganic. We need not dis- 
cuss here the question of catastrophism and uniformitarianism in 
geology. However much the lattei' prevails at the present time, 
both have doubtless operated in the past. Catastrophism would 
necessarily produce gaps, or saltations, in the palaeontological 
record, as only the more plastic species would adapt themselves 
and survive under its influence. It is not gaps due to such causes 
that are here to be considered, however, but those which occur in 
uniform strata. Haldeman has most suggestively remarked that 
the same mineral will crystallize with three, six or twelve angles, 
but not with five or seven, and he asks: are the facts of organic 
morphism subject to less definite laws? Cope has drawn another 
illustration from inorganic forces, in the three great changes in 
water, from solid, liquid and vapor, which take place suddenly at 
what may be called three expression points of the thermometer, the 
many intervening degrees involving no change. Rhythm or wave 
movement would seem to be a universal attribute of matter, whether 
organic or inorganic. The forces of nature are constant, but the 
phenomena induced are often paroxysmal. The progressive forces 
accumulate, while the conservative forces resist until at last resist- 
ance gives way with comparative suddenness. There is every rea- 
son to believe that the life movement, in its ascending complexity, 
has shared this common law. Accumulation is proportioned to the 
change in environment, and resistance to the age or rigidity of the ADDRESS BY C. V. RILEY. 
37 
organism. The latter may be strong enough to end in death or 
extinction, or it may break down and, with comparatively sudden 
yielding and conformity to necessity, burst the confines, and begin 
a new series of variations and adaptations. In either case we have 
breaks, because the dying or dropping out of one type makes room 
for another, more accommodating. Rapid evolution, from causes 
already discussed, implies gaps which must be marked according as 
the strength of the conservative forces and the violence of the final 
accommodation are great, and because sudden breaks are more apt 
to occur after long periods of stability. The break may be in- 
duced by changes in physical environment or without such change ; 
if the latter, it will more likely occur in some individual, born 
with a marked departure from the type that gives it some advan- 
tage, and whose issue will in time supplant all other individuals. 
In either case, we shall have, palaeontologically, distinct species or 
genera, one superposed on the other, without links. To the imper- 
fection of the geologic record is to be attributed, no doubt, a large 
number of these gaps yet existing between types, and many im- 
portant links, or branches, are yet to be discovered. Yet the views 
we have been considering should absolve evolutionists from all 
necessity of demonstrating the more minute gradations; because, 
in deposits like the Tertiary, during which we may assume life- 
conditions to have remained comparatively uniform, these saltations 
take place. Saltation, or, what is probably a truer expression, 
wave-movement, would indeed seem to be a prerequisite of prog- 
ress and will account for much that is going on even at the pres- 
ent day. In artificial selection by man we find that it is at first 
comparatively easy to accumulate minute peculiarities and varia- 
tions by rigid breeding and exclusion of all deviation ; but that 
we soon arrive at a fixed point which is maintained at first with 
difficulty but with increasing ease with each generation. During 
these more fixed periods the potentiality for change is doubtless in- 
creasing, until at last it is suddenly manifested in renewed varia- 
tion. Rest is followed by activity just as surely as activity induces 
and requires rest. 
There is a limit to development in organs, just as there is a limit 
to individual mental growth. Weariness of previous effort comes 
upon us when the limit of result is attained, accompanied by great 
longing for change and not infrequently with revulsion from pre- 
vious effort. The naturalist who has devoted a part of his life to 38 
SECTION F. 
the persistent accumulation of facts and specimens, has held the 
imaginative and generalizing powers in abeyance during that period. 
The reserve brain force in this direction may be suddenly called 
into activity by exhaustion in the other, and the process may per- 
haps be comparable to the exhaustion of the soil for one particular 
crop, without lessening its fertility for some other, the recognition 
of which fact is the foundation of all successful agriculture. Ex- 
cess of development, whether in body or mind, inevitably brings 
about either wholesome reaction or utter collapse. 
How far the rhythmic tendency in the development of animal 
life may be explained by the rapid change of climate, by migration 
and the loss of record, or upon the general law that while there 
has been progress of the whole, there has not necessarily been 
progress of every part, it would take us too far to discuss in this 
connection. I think we are safe in saying, however, that the facts 
justify belief that, in the evolution of animal life, as in the evolu- 
tion of everything else, progress has often been made by waves. 
The Fiskean Law.-With regard to what may be called the Fisk- 
ean law of correlation between brain development and infantile 
dependency, Fiske has so admirably elaborated the subject that it 
needs no further elucidation here as the principal factor in the ev- 
olution in man, first, of the family relation, then of the clan, the 
tribe and the nation. With this factor in mind, and the immense 
superiority which anthropoid man must have had, when brain de- 
velopment had once induced this fundamental community of inter- 
est, over the rest of brute creation, the gap between primitive man 
and the higher anthropoid apes in the past or between the present 
lower races of man and the higher existing primates is easily ex- 
plained, even if it had not been greatly exaggerated. At the pres- 
ent time we may note and record the further inevitable increase 
in the gap, for the lower races of man are gradually becoming ex- 
tinct and the higher apes cannot long hold their own or persist. 
The Brooksian Hypothesis. -I have already alluded to Brooks's 
hypothesis under the head of sexual differentiation, and his work 
on Heredity must be so familiar to you that his views need but 
a passing notice. He believes that sex differentiation means fun- 
damentally a physiological division of labor and that the male is 
essentially the progressive or diversifying and the female the con- 
servative agent. As organisms gradually increased in size ; as the 
number of cells in their bodies became greater, and as the differ- ADDRESS BY C. V. RILEY. 
39 
entiation and specialization of these cells became more and more 
marked, one element, the male cell, became adapted for storing up 
gemmules and, at the same time, gradually lost its unnecessary 
and useless power to transmit hereditary characteristics. 
The theory finds support in some of the phenomena of life and 
doubtless expresses a law not easily established, for which reason 
it will not be readily accepted. It leaves entirely out of consider- 
ation some of the forces at work which I have already indicated 
and in so far must be considered only a law of secondary impor- 
tance. However much we may admit the general truth that the 
germ cell continues the past and the sperm cell tends to diverge 
from it, as a purely dynamic proposition, inducing variation for 
natural selection to play upon, it does not in any way decrease the 
overwhelming importance of the female in inducing, through psy- 
chico-physiological influences, a needed and purposeful modifica- 
tion in the manner which I have already expounded. 
Having thus considered some of the proximate causes of varia- 
tion and some of the more general laws of evolution we are natu- 
rally led, in conclusion, to consideration of original or Infinite Cause. 
Far be it from me to try your patience with any prolonged specu- 
lation upon the more profound problems of life and of futurity 
which have been dealt with by able men of all times and with such 
conflicting and varying results. I shall content myself, in closing, 
with a few words upon those themes which, as biologists, we can- 
not ignore, and to which the subjects we have been considering in- 
evitably lead. 
Mind, as exhibited in organic evolution, however simple or com- 
plex may be its manifestations, is, in essence, one and the same 
force. There is an undoubted gradation from simple sensitiveness 
and volition, to the more complex instinctive and reasoning facul- 
ties of higher animals. The concensus of opinion of biologists 
who have given the subject any serious consideration is that ani- 
mals exhibit all our mental endowments in degree. They possess 
desire, affections, imagination, memory, comparison, judgment, 
and all the other attributes of human intellect, more or less per- 
fectly developed, and there should be no more doubt of the gradual 
evolution of man's intellect from preexisting lower and simple 
forms of aggregate mind, than there is in the derivation of his more 
complex and powerful brain (the medium of mind) from smaller and 
simpler brains, or of his body from simpler, less specialized forms. 40 
SECTION F. 
Some of our profounder thinkers feel that all the phenomena of 
the universe are but forms of motion, and that the great final and 
creative force may best be imagined as the centre and the source 
of motion. In this light, it is, perhaps, not too much of an exag- 
geration to conceding to plants a certain amount of mind, and in 
establishing the fact of universal movement in plants ; in showing 
that circumnutation is an inherent quality or manifestation of plant 
life, Darwin may well be said, as Professor Ward has expressed it, 
" to have gotten at the final cause of all evolution." Indeed, it 
must be difficult for a botanist, considering that all the terminals 
of a plant, whether beneath or above the ground, are constantly 
feeling and choosing ; or when he reflects on the wonderful motions 
and selecting power of climbing plants, but more particularly on 
the strange phenomena exhibited by insectivorous and entomoph- 
ilous plants ; it must be difficult for him, I say, to relegate to the 
limbo of the unconscious, the whole of his pet kingdom. In his 
letters, especially to Hooker, Darwin says, speaking of the circum- 
nutation of Echhnocystis lobata: "The tendrils have some sense, for 
they do not grasp each other when young," and again of the move- 
ments caused by light, gravitation, etc., he says : " It has always 
pleased me to exalt plants in the scale of organized beings, and I 
have therefore felt an additional pleasure in showing how many 
and what well adapted movements the tip of a root possesses." In 
studying the movement of flowers, especially in their sexual rela- 
tions, I have often felt, with the poet: 
" 'Tis my faith, 
That flowers enjoy the air they breathe" 
and that, however much conscious sensation may have lapsed in 
most of their manifestations of growth, sensation may still be con- 
scious, and mind still work, in dim fashion, during the season of 
reproduction, in the specialized and reproductive parts. It may 
be a fancy, but who can prove it unjustified? 
Where, then, shall we draw the line in the evolution of mind be- 
tween the high degrees of consciousness in animals and self-con- 
sciousness which is believed to be a peculiarly human attribute and 
at the foundation of all that constitutes con-science and makes him 
a moral and responsible being? The beginnings of self-conscious- 
ness are traceable in animals, since many of the phenomena of 
sexual selection and the well known sense of shame in our domes- ADDRESS BY C. V. RILEY. 
41 
tic associates could scarcely have resulted without it, and it seems 
to me illogical to argue, as some of our best writers on evolution 
have done, that self-consciousness is an attribute that must have 
been breathed into man by special, supernatural act. 
From the consideration of the general subject of mind in nature, 
we are brought inevitably to the question of Design. There can 
be no doubt that the tendency of evolution has been to remove 
further and further the idea of an Infinite First Cause, and pure 
Darwinism exhibits to us a cold and cruel world,-exemplifying 
the Hobbesian theory of self-love, nothing having any reason for 
existence except its own welfare. It leaves out all the higher be- 
atitudes of nature, the higher aspirations of men, and all those in- 
ternal yearnings or laws of internal growth and influence, not for 
the individual alone, but for the good of the whole. Natural se- 
lection, while not disproving Design, pushes back the argument 
and limits it to the order of nature as a whole, since much of the 
modification and adaptation is accounted for by known and rec- 
ognized physical conditions. The argument for design, however, 
as Asa Gray has so well set forth, rests on the fact that the de- 
signed and the contingent can never be accurately discriminated 
and that limitation, in the very nature of the case, is inconceivable. 
There are those who see only in nature the inevitable and neces- 
sary manifestation of the forces of the universe, and assume them 
to have been without beginning and to be without end. There are 
others who find in the unity-the oneness-of the forces of nature 
full evidence of Design. So far as logical inquiry will aid us, the 
recent controversy between Messrs. Cope and Montgomery may be 
cited as typical of that which has always separated the two schools, 
and sufficiently shows how opposite conclusions may be reached 
by those equally able and equally conversant with the evidence. 
The former contends that mind exists independent^ matter, or, 
to use his own words, "primitive consciousness exists in primitive 
forms of matter and constitutes a primitive person, or Deity while 
the latter maintains that the mind of living beings is, itself, only 
a product, or outcome of their organization. 
Darwin, as is evident from the "Life and Letters," was induced 
by his life-work gradually to abandon the rigid tenets of the Christ- 
ian church, and to substitute therefor a more latitudinarian form 
of belief. He was content to limit his investigations to truly scien- 
tific methods, realizing fully that all speculation in reference to the 42 
SECTION F. 
great First Cause involves the discussion of the supernatural which 
is necessarily beyond the natural. The discussion of these ques- 
tions can be very little affected by the methods of natural science 
and the more thoroughly we recognize this fact the better it will 
be for both religion and science. It ill becomes us to be dogmatic 
in questions beyond the limits of induction, or where the mind at- 
tempts to fathom by deduction and speculation. Natural science 
necessarily deals with natural causation. 
A few expressions from the " Life and Letters " may he quoted 
here. Darwin says : "The old argument of design in nature, as given 
by Paley, fails now that the law of natural selection has been dis- 
covered. We can no longer argue, for instance, that the beautiful 
hinge of a bivalve must have been made by an intelligent being, 
like the hinge of a door by man. There can be no more design in 
the variability of organic beings and in the action of natural selec- 
tion, than in the course the wind blows." He asks whether we are 
to believe that organic forms in nature are preordained. If so, 
why should we not believe that the variations of domestic animals 
and plants have been preordained for the sake of the breeder ; yet 
if we give up the principle in the one case we must do so in the 
other. Again : "No shadow of reason can be assigned for the be- 
lief that variations in nature have not been the result of the same 
general laws which have formed the groundwork, through natural 
selection, for the formation of the most perfectly adapted animals 
in the world, man included, without intentional or specific guide." 
Yet, while he was willing to remain an agnostic, feeling that the 
beginning is insoluble by us, he gave some of the most cogent rea- 
sons, aside from the feelings and emotions, for the belief in the ex- 
istence of a First Cause-of a God. In his correspondence with 
Gray, he shows how he cannot bring himself to believe that a 
beneficent and omnipotent God could have designed the charac- 
teristics of parasitic and carnivorous creatures, with all the other 
heartless manifestations in nature. Yet he was not content, in com- 
templating the nature of man, with the idea that everything is the 
result of blind force. He believed in design with the details, whether 
for good or bad, left to the working of what, for want of a better 
term, we call chance. With the utmost candor, he confessed that this 
view was not at all satisfactory to him, but that the whole subject 
was too profound for the human mind, likening our speculations 
upon it to those of a dog on the mind of Newton, and believing ADDRESS BY C. V. RILEY. 
43 
that each man should hope and believe what he could. Again, in 
a letter to Lyell, June 4, 1860, he remarks, " As squared stones, 
bricks or timber are indispensable materials for a building and in- 
fluence its character, so is variability indispensable in influencing 
selection and that, " in the same manner as an architect is the 
all-important person in the building, so is selection with organic 
bodies." The parallel is evidently weak here and we may well in- 
sist that from Darwin's own statement, the idea of an intelligent 
architect or designer in the one case is as all-important as in the 
other. The same is true to some extent of the argument from ar- 
tificial selection, or the manner in which intelligent action in man 
acts on domestic or cultivated organisms. This is not limited to 
the mere choosing of chance variation in beneficial directions, but 
involves also purposeful feeding, training and treatment, to induce 
the desired amelioration and variation. Just as the production of 
new forms among domestic animals or cultivated plants implies a 
purpose-a designer ; so may the origination of such forms in Na- 
ture imply intelligent design. Both Lyell and Gray believed in 
the form of variation having been planned or designed. It seems 
to me that the evidences of design in nature are so overwhelming 
that its advocates have an immense advantage over those who 
would discard it. A fortuitous cosmos is, to most persons, utterly 
inconceivable; yet there is no other alternative than a designed 
cosmos. To accomplish anything by a process, or by an instru- 
ment, argues greater, not less power, than to do it directly, and 
even if we knew to-day all the causes of variation, and understood 
more thoroughly than we do the method of evolution, we should 
only carry the sequence of causes a step farther back and get no 
nearer to the Infinite or Original Cause. 
The most philosophic view is, probably, that which, while rec- 
ognizing an intelligent creative power, or mind, which has worked 
and is yet working through ordained laws, yet leaves the detailed 
manifestations to secondary causes and finite action. Limiting 
conditions, or laws, since law is but a limiting condition and nature 
an active power, may act together in producing secondary causes 
but the great and Infinite Cause may be looked upon as that which 
upholds the universe. 
The tendency of those who would advance theological conceptions 
from evolutional grounds is doubtless to some monotheistic form, 44 
SECTION F. 
or a sort of psychical pantheism, which sees the Infinite immanent 
in Nature - an all-pervading, interpenetrating Essence. This is 
the All-conscious, and I know of no better intellectual conception 
of immortality than resolution of the finite individual life and con- 
science into the All-life, All-conscious-a conception justified and 
affirmed as it is by evolution. But the one great point which I wish 
to emphasize in alluding to these differing views is, that, beyond 
the limits of the scientific method, speculation becomes faith and 
the most profound writers are obliged to use the simple I believe 
which most theologians begin with. The sentiments which consti- 
tute true religion - the sense of impenetrable mystery and moral 
obligation ; the higher humanitarian promptings and hope of fu- 
ture life,- are apart from science and cannot, therefore, be affected 
injuriously by its methods. 
Evolution logically involves the idea of the origination of life 
from the inorganic forces at work on our globe and only in this 
sense does it modify our conception of the Creator. The one vivi- 
fying force in nature must needs be an endless source of power and 
movement, with the potency of all that is in what we call universe. 
Art and plan being manifest therein the power must needs be in- 
telligent, and we can compare it with nothing more satisfactorily 
than with our own conscious thinking power, whether we call it 
soul, spirit, the Absolute, the Infinite, the Unconditioned, the Un- 
knowable, the Creator, the Divine Mind, the Supreme Will, God, or 
by what other nominis umbra we choose to express the conception. 
And now, Ladies and Gentlemen, wisdom admonishes me to be 
brief. I have ventured just within the question of design because 
of the prevalent belief that evolution eliminates it from our con- 
ception, and because I have felt that as between the extreme schools 
the middle ground chosen by our late lamented Gray, is far the 
more satisfactory and philosophical. On the other great question 
of what life is, or how it originated, I commend the candor of Marsh 
in closing his address as president of the Association in 1877 with 
the words "In this long history of life, I have said nothing of what 
life is. And for the best of reasons, because I know nothing." 
If we endeavor to formulate the idea of life we shall not lack 
for excellent guidance in past utterances of those who have been 
and who are yet members of this section of the Association. In 
fact we may well feel proud to live in the generation which has pro- ADDRESS BY C. V. RILEY. 
45 
duced some of the ablest experimenters whose work will have en- 
during influence in bringing us nearer to a true comprehension of 
the forces under which we live. Professor Barker, in his presi- 
dential address for 1880, on " Some modern aspects of the life 
question," seemed to some of us on the verge of chemically and 
physically explaining and defining the thing itself; and, yet, though 
we seemed, while listening, to near the gates which opened the 
secret we got but a glimpse into the great mystery. It matters 
very little whether we follow the great writers who have wrestled 
with this question in the past, or those who have been or are still 
with us, we must acknowledge our utter incapacity to comprehend 
the most patent phenomena of our being. We try in vain to an- 
alyze life ; we try equally in vain to measure thought. 
A little transparent colorless material christened protoplasm is 
believed to be the physical basis of life and the seat of all those 
marvellous powers and properties belonging thereto. We may trace 
back from death and dissolution the individual life to its very gen- 
esis in the organized cell, or ovum ; we may go farther back, and 
trace it to the unorganized nitrogenous hydro-carbon compound 
which has been named protoplasm ; but we yet fail to apprehend 
the cause of its vital functions, of its powers of assimilation, irrita- 
bility and reproduction-the potentiality of the living as compared 
with the dead stuff. So in the past history of the type, we are led 
back to the same mystery. Ontogeny and phylogeny alike lead 
us to the riddle of the beginning of life. Huxley may well say that 
the process of development of the egg, like that of the seed, is 
neither more nor less mysterious than that by virtue of which the 
molecules of water, at the freezing point, build themselves into reg- 
ular crystals. In either case it must be very largely a question of 
temperature. But while in the case of water the effect is at a fixed 
degree, in the case of organic life the degree is variable. We may 
say, with one of our most profound and respected writers, that or- 
ganic compounds are "substances whose highly complex and very 
unstable molecules are composed themselves of inorganic com- 
pounds or of organic compounds of lower organization formed on 
the cool surface of fully developed plants at life-supporting temper- 
atures." We may assume that increasing complexity and instability 
of nitrogenous substances give us proteids and finally protoplasm. 
We may find that the forces upon which the movements and changes 46 
SECTION F. 
of this substance depend are the very same which determine those 
of a drop of water or a bit of mucilage; that all its movements 
are referable to the mechanics of molecules as exhibited in liquids. 
But the fact remains that the physicists who help us to a better un- 
derstanding of the material properties and processes of protoplasm 
are only dealing with the methods and no more solving the great 
mystery of life than did Darwin or any of the other workers who 
have helped us better to comprehend its processes. 
It was my privilege in years gone by to meet frequently with a 
little coterie of metaphysicians in St. Louis which included men 
like Wm. T. Harris and Thos. Davidson, who have acquired na- 
tional reputation. With strong inductive tendency of mind I was 
all the more anxious to follow their erudite discussions of the phi- 
losophies of Aristotle, Kant and Hegel, but was too often over- 
whelmed with the feeling that my friends were dealing in mere 
words and that philologic juggling too often passed for reason. 
May we not truly say the same of those biologists who endeavor to 
give us a purely physical or materialistic explanation of life ? I 
have certainly sometimes felt, in following their writings, that we 
scarcely get away from the thraldom of mere words. I felt this 
strongly, again, while listening to the symposium by a number of 
our greatest authorities (Schafer, Lankester, Krause, H. M. Ward, 
Carnoy, Hartog, Gardner and Sedgwick) on the present aspects of 
the cell question at the meeting of our sister society in Manchester 
last autumn ; for if there was one result which clearly came out of 
the discussion it was that protoplasm is not a mere chemical sub- 
stance but a complex structure. Yet what stupendous import has 
been given to it in biologic literature, since Von Mold first used it 
to indicate the slimy substance within the vegetal cell and Huxley 
aggrandized it as the "physical basis of life." Neither it, nor Lan- 
kester's plasmogen, nor Weismann's idioplasm, nor Coues's tran- 
scendental biogen, helps to any more real conception of life itself 
than does Hinrichs's pantogen which he calls the "primary chemi- 
cal principle or the element of elements," and upon which he bases 
his theory of ato-mechanics. 
The genesis or formation of individual life, in spite of saint and 
sage, is yet a mystery and probably always will be, and the exact 
site of the origin of the reproductive cells, according to one of our 
best authorities (Allin Thompson), is even a matter of doubt. ADDRESS BY C. V. RILEY. 
47 
"Hunt as we will all matter to the end, 
Life flits before it: last as first we find 
Naught but dead structure and the dust of fact; 
The infinite gap we cannot apprehend, 
The somewhat that is life-the informing mind." 
All that evolution recognizes is the transmutability-the generic 
identity-of the forces of Nature, which, in their aggregate action, 
may properly be defined as omnipresent energy. We know, as a 
matter of the simplest observation, that this combined force, or 
energy, is essential to the continuance of life, not only upon our 
planet, but, deductively, in the universe. We are justified in infer- 
ring that it is capable, under fit conditions, of originating life, from 
what we know as non-living matter. Evolution, in fact, inevitably 
leads to the inference that vital force is transmutable into, and de- 
rivable from, physical and chemical force. It implies, and neces- 
sarily implies, abiogenesis, either now or at some remote period 
in the history of our earth ; and notwithstanding experimentation 
and advance in our knowledge of micro-organisms overwhelmingly 
refute Bastian's conclusions, or the idea of the present origination 
of organic from inorganic matter, so far as forms within our ken 
are concerned, yet it seems to me perfectly logical to infer a world 
of beings which our strongest instruments fail to reveal to us, 
among which abiogenesis is possible to-day or archebiogenesis was 
in the past, just as the molecule is a necessary physical conception 
though it may never be revealed to us. 
It may be true that phylogeny postulates the derivation of all 
forms of life from a similar simple cell and that, to use Joseph 
LeConte's language, "the fundamental law of embryology teaches 
us that the history of the phylogenetic evolution of organisms is 
mirrored in miniature in the ontogenetic development of each in- 
dividual but in ontogeny the simple cell from which the individual 
starts has a potentiality, a something which makes it different from 
another and it does not help us much to have this something called 
the memory of the plastidules. 
We have thus been led, while considering the causes of evolution, 
to the conviction that they ar^in the end referable to an Infinite 
First Cause and that evolution in nowise dispels the idea of a 
Creator, or need in any way affect religious sentiment; for,while it 
destroys much of the folly and superstition that belong to the ideas 48 
SECTION F. 
which grew out of the false notions of cosmogony prevalent in the 
early infancy of the race, it points to higher and nobler forms of 
religion and to a better code of morals. Religion is born of the 
" delirious yet divine desire to know," and largely grows out of 
unexplained phenomena. Evolution is a principle which to-day 
pervades and rules the whole realm of philosophy. It establishes 
a noble conception of Divine nature, and exhibits God in his works. 
No longer "one touch of Nature" but, essentially, "Evolution," 
"makes the whole world kin." It is a bond that holds all life to- 
gether. It shows us man as a part of the life everywhere about 
him, and promises advantage to him in more intimate knowledge 
of that life from which he used to think himself entirely severed 
by Supreme will. 
Evolution teaches that nothing is yet so perfect but it may be 
improved ; that good comes of the struggle with evil and the one 
can never be dissociated from the other. The erect position which 
has given man his intellectual preeminence, has brought him man- 
ifold bodily ills. No evolutional sibyl looks to a milennium. 
Higher development must ever mean struggle. Evolution shows 
that man is governed by the same laws as other animals. Environ- 
ment has induced some of his most marked race characters, and 
individual variation is greater in him than in most creatures, and 
this is his surest promise of betterment. The dime-museum is elo- 
quent of the fact that were any bodily variation useful, from an 
elastic skin to a hundred and one abnormal qualities, selection 
would have no end of variation to choose from. Differentiation has 
gone on and is going on to make him the most heterogeneous in 
function, whether of brain or muscle, of all species. The differ- 
ence between the hand of a Josef Hofmann and of the average plow- 
man is one which involves a large number of correlated differences 
and is functionally, if not structurally, greater than that between 
the non-opposability of man's great toe and its opposability in the 
higher apes-a difference which has been so much made of but 
which finds its gradations in eastern peoples who use their toes in 
" handling " tools. 
Evolution is particularly promising to us as a people. 
" The spirit grows with its allotted spaces; 
The mind is narrowed in a narrow sphere." 
The diversified environment and the commingling of so many ADDRESS BY C. V. RILEY. 
49 
nationalities have stimulated variation and progress, making us al- 
ready foremost in invention and material growth. The distinctive 
American type, not yet fixed but forming rapidly, must profoundly 
influence man's future on the globe, and evolution teaches that by 
so far as the contest is severe with those forces which are disin- 
tegrating and destructive to liberty will the final improvement be 
greater. The effort and advancement of to-day, in all directions, 
will form the inheritance of future generations. 
But the struggle for existence in civilized man is no longer one 
solely for physical adaptation to natural environment or physical 
supremacy, but is one rather of ideas and purposes. It goes on 
in an environment of intellect and morals. 
In addresses before this Association, Professor Morse has elo- 
quently alluded to some of the more practical teachings of evolu- 
tion as they should (and in the future doubtless will) affect gov- 
ernmental and political action. The higher forms of human law 
and order acquire meaning when we realize that crime is largely 
the persistence of ancestral traits, and that our laws are best when 
best suited to eliminate these barbarous propensities from the race. 
We can scarcely do our duty even to the criminal without a due 
comprehension of the power of heredity to jump back to an ances- 
tral copy even in minutest detail. 
The old forms of theology have encouraged a species of para- 
sitism by denouncing man, as a whole, as condemned to eternal 
damnation-as inherently wicked by inheritance-and by offering 
him salvation through the help of others. Evolution teaches the 
care and preservation of the body and not its sacrifice ; it teaches 
that right-living and right-doing ennoble ; that inactivity, parasit- 
ism, viciousness of every kind, are degenerative forces in bringing 
disease and suffering and retribution. It shows that the worst ills 
are part of a legacy which no court admits to probate, but which 
nature executes relentlessly. It teaches the importance of proper 
environment and influence, especially in childhood, in order to im- 
prove what we may inherit for good, and counteract what we may 
inherit for bad. It shows the necessity of establishing the habit 
of right-doing and right-thinking where the old systems neglected 
both body and mind and relied on preaching and punishment. It 
teaches that our moral and penal codes should be so framed as to 
prevent the propagation of diseased and vitiate constitutions. It 
teaches that every increasing advance follows use and eflfort, while 50 
SECTION F. 
degeneracy follows disuse and stagnancy. It teaches that man has 
risen from a lower, not fallen from a higher state ; that from sim- 
ple social conditions complex ethical conditions have resulted. It 
teaches that no work is complete and posits of man unlimited ad- 
vancement in the future ; for every advance in knowledge and every 
new application of science increase his moral power. 
Ecclesiasticism lands the naturalist in skepticism and doubt of 
all that has been taught him as to the past and the future. Evo- 
lution reveals a past which disarms doubt and leaves the future 
open with promise-unceasing purpose-progress from lower to 
higher. It promises higher and higher intellectual and ethical at- 
tainment, both for the individual and the race. It shows the 
power of God in what is universal, not in the specific; in the laws 
of nature, not in departure from them. It may lead to some mod- 
ification, as compared with Judaism, of the ideas of the future as 
it has of the past; for if the possession of the higher attributes 
which we denominate by the term Soul is the best promise of im- 
mortality, I believe there are many dumb creatures who are surer 
of it than many human brutes. All the word-moulding ; all the 
rhetoric ; all the sophistry, of those who, cradled in Mosaic the- 
ology but graduated in evolution, attempt to frame from the teach- 
ings of this last a post-mundane heaven of unalloyed joy for man 
alone, must in my judgment, come to naught. Their efforts re- 
mind me of the reconcilers whose business is, as Huxley has so 
well put it, "to mix the black of dogma and the white of science 
into the neutral tint of what they call liberal theology." Let us 
not deceive ourselves I What we accept as to the resurrection of 
the individual is based on other evidence than that of evolution, 
and is mainly a matter of Faith, and when it comes to forms of 
Faith, those are best which best subserve the moral and intellectual 
growth and development of society and which at the same time 
bring comfort and hope to the individual. The few great beliefs 
which have controlled the religious sentiment of the world have 
all helped to those ends and have been good in their day and clime. 
The teachings of Christ, in their simpler and purer inspiration, 
and freed of the narrowing incrustations of schism and dogma, 
transcend them all, and are, in fact, an evolution from them. Our 
faiths will vary as they have varied. Those who have attained to 
altruism may find sufficient joy and reward in present existence 
with its love and duty and conscious self-development, and rest ADDRESS BY C. V. RILEY. 
51 
satisfied to leave to destiny the future after death; to candidly 
avow them ignorant of it -agnostics. Others may feel no regret 
in the conviction that there is no continuity of state but only of 
being ; that eternal unconsciousness-eternal rest-awaits the close 
of individual life. But we should not forget that the mass of 
mankind are incapable of like unconcern, and that a Faith to them 
is precious and even necessary. Nor should we forget that the 
evolution which we, as individuals, have undergone, with all its 
risks and dangers, awaits every new individual born. The child 
up to a certain age, and the mass of mankind at maturity are, in 
apprehension, only as our savage ancestors, and must be taught 
the truth according to their light. The experience gained by 
those who have reached the highest ethical and intellectual growth 
must be formulated in precept and principle to be of any benefit to 
society at large, and the higher ethical sentiment and religious be- 
lief-faith, love, hope, charity-are priceless beyond all that exact 
science can give it.