Haeckel's Genesis of man, or, History of the development of the human race. Being a review of his "Anthropogenie", and embracing a summary exposition of his views and of those of the advanced German school of science

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HE three papers constituting this little dvochure were originally
contributed to the Penn Monruty, and appeared in the April,
May, and July numbers of that magazine for 1877.

As the work which it was their more especial object to review
has not yet been placed before the non-German reading public, no
apology is offered for their reproduction in separate form.

In view, however, of the popular interest which the views
of Prof. Haeckel have since called forth, and which seems to be
still increasing, it was thought an opportune moment for laying
before the general public this condensed exposition of the thought
and labors of the great naturalist and philosopher.

It may further interest the reader to learn that Prof. Haeckel
has acknowledged, in a private communication to the author, the
substantial correctness with which these papers represent his

position.
ee We
Washington, March, 1879.

FPN CME:S) GENESIS ZOF MANY OK SIISTORY: OF THE
DEVELOPMENT OF THE HUMAN RACE!

I.

GENERAL HISTORY OF THE DOCTRINE OF DESCENT.

T is no derogation from the epoch-making labors of Charles
| Darwin to admit that the arguments he has presented in sup-
port of his celebrated theory constitute, as it were, but the half of
the vast array which the present state of biological science is capable
of marshalling in its defence.

The sources from which the evidences of descent and natural
selection must be derived, may be divided into two general classes:
First, Paleontology, Comparative Anatomy and Osteology, and
Geographical Distribution (Chorology), 1. ¢.,a comparison of the
adult forms of animals both living and fossil (Phylogeny); and
Second, the study of embryonic changes and post-natal metamor-
phoses, or a comparison of undeveloped animal forms (Oxfogeny).
Of these two classes it may be said that the first have been fur-
nished by Darwin, the second by Haeckel. Not that Darwin,
either in his Origin of Species or in his Descent of Man, has wholly
ignored the bearing of embryological considerations upon his
theory. In the former work he has devoted seventeen pages of
one of his concluding chapters to “ Development and Embry-
ology ;” the greater part of which, however, is occupied in pointing
out the importance of the various kinds of metamorphosis, chiefly
as it is observed in insects, amphibians, etc., after birth; only inci-
dentally referring to those more obscure metamorphoses which
take place within the egg or the uterus.

He does allude, however, more directly to Von Baer’s law, but
without designating it as such; and contents himself with quoting
the passage, cited also by Haeckel in the preface to the third edi-
tion of his Afzstory of Creation (1870), in which the great Russian
embryologist remarks upon the striking similarity of many em-

1 Anthropogenie, oder Entwickelungsgeschichte des Menschen, von Ernst Haeckel,
Professor an der Universitat Jena. Leipsic, 1874.

6 GENESIS OF MAN.

bryos, so much so that he was quite unable to say to what animals
two specimens which he had preserved in alcohol but had neglected
to label, really belonged. Still less attention has Darwin paid to
this source of argument in his Descent of Man. A few lines quoted
from Von Baer and from Huxley, on page 14 of Vol. 1, a figure of
the embryo of a human being and one of a dog, from Ecker, on
page 15, with brief comments, disposes of this branch of his great
argument. Almost as much had been said by the author of the
Vestiges of Creation, in 1842? It is safe, therefore, to assume
that at the time of the appearance of the Ovzgin of Species (1859),
Darwin had no conception of the real part that the arguments from
embryology were destined to play in establishing his doctrine
of the development of organic forms. And although in subse-
quent editions he was able to notice the Generelle Morphologie, it is
still improbable that even then he had any adequate idea of the
powerful ally he was to have in Germany, as the Wadiirliche Schopf-
ungsgeschichte,and not less the work under review, have proved
the professor of Jena to be. "Tt is of the former of these works
that Darwin says that if it had appeared before the Descent of
Man had been written, he would probably never have completed
the latter.

Professor Haeckel is no mere disciple of Darwin, profound as is
his admiration of him, and unreserved as is his expression of that
admiration. His own countrymen have accused him of being
“more Darwinistic than Darwin himself,’ but it is clear that a
large part of this difference is in kind rather than in degree, and
that he has infused into the developmental philosophy a true
Haeckelian element. It is true that he drew the logical conclusion
from the premises furnished by the Origin of Species five years be-
fore the announcement of its recognition by Darwin himself in his
Descent of Man. ‘This conclusion he boldly and forcibly enunci-
ated in the introduction to his Generelle Morphologie, published in
1866, and reiterated with still greater emphasis in his Watirliche
Schipfungsgeschichte,in 1868. Between this period and that of the
appearance of the Descent of Man, Haeckel was exposed to the
bitterest attacks, not only from the adherents of the Church and
the opponents of Darwin generally, but from those adherents of
Darwinism in Germany—and they were many—whose conception

-2New York, 1845, p. 150. |

GENESIS OF MAN. 7

of it was limited to the body of principles contained in the Origin
of Species. As in that work all reference to the position of the
human race in the animal kingdom was carefully excluded, thus
ingeniously avoiding the shock of prejudice which any such con-
nection would have occasioned, the simplicity, the zaivezé, and, at
the same time, the force of reasoning displayed in it, not only
won the immediate assent of ‘all fully emancipated minds, but
took a strong hold upon great numbers of liberally educated per-
sons whose independent reflections had not yet carried them wholly
out from under the influence of theological conceptions. Among
these were many thoroughly scientific men and naturalists, special-
ists in the various departments of science, whose analytical labors
had not left them time fora synthesis of the facts even within their
own special branch of research. These accepted the conclusions
drawn in the Origin of Species without perceiving that other and
important ones might and must follow from the same premises.
And because Haeckel drew these logical and necessary conclu-
sions, these persons attacked him from all sides, and heaped upon
him every form of accusation. Besides the charge above referred to
of out-Darwining Darwin, and of going further than Darwin him-
self would ever sanction, there was added the stronger one that
Haeckel knew nothing about true Darwinism. The appearance in
1871 of Darwin’s Descent of Man placed these anti-Haeckel Dar-
-winians in a most embarrassing situation, silencing many, convert-
ing numbers, and driving not a few into the theological camp.
But Haeckel emerged majestically from the battle, unscathed and
undaunted. To charges of “radicalism” he had simply replied:
«Radical thinking is consistent thinking, which allows itself to be
checked by no barriers of tradition or of enforced dogma.” To
the confused outcry of the theological school and of the anti-Dar-
winians in general, he did not deem it worth his while to reply.
A satirical remark upon this class, however, is worth reproducing
and might be ranked alongside of Darwin’s cutting sarcasm,
wherein he says that he who scorns to be descended from a beast
will generally reveal his descent in the act of sneering, whereby he
will expose his canine teeth. “It is an interesting and instructive
circumstance,” says Haeckel, “that just those persons are most
shocked and indignant at the discovery of the natural development
of the human race from the apes, who, in their intellectual develop-

8 GENESIS OF MAN.

ment and cerebral differentiation, are obviously least removed
from our common tertiary ancesfors.”

Both in his Hzstory of Creation and in his Anthropogeny, Haeckel
has done a service to the cause of evolution by reviewing, in a fair
and disinterested manner, the history of the origin and progress of
those ideas which have culminated in the Darwinian theory. Let
us glance for a moment at this history.

Passing over the names of Wolff, Baer, Kant, Schleiden, Oken,
and Humboldt, in Germany, of Buffon and Geoffrey St. Hilaire,
in France, and of Dean Herbert, Professor Grant, Patrick Matthew,
Freke, and Herbert Spencer (Assays, 7852), in England, all of
whom had given more or less definite expression to these pro-
gressive ideas prior to the appearance of the Origin of Species, it
may be remarked that the great conception of the natural relation-
ship (filiation) of all organic forms and their descent or development
from common ancestors that have existed in more or less remote
periods of the past, had a threefold independent origin in the minds
of three men who were contemporary at the close of the last and
the beginning of the present century, in each of the three great
nations that now lead the intellectual world. These men were
Erasmus Darwin, grandfather of the illustrious Charles, in Eng-
land, Wolfgang Goethe, the great poet and philosopher, in
Germany, and Jean Lamarck, in France. Wholly unacquainted
with each other and with each other’s works, these three men,
almost at the same time, gave utterance to substantially the same
fundamental ideas, and elaborated in more or less extended and
systematic form the essential ground-principles which now underlie
the edifice of all progressive biological science.

In his work entitled Zovnomia, published in 1794, Erasmus
Darwin lays great weight upon the transformation of species
of animals and plants through their own activities of life and
through forced habituation to changed conditions of existence.
It is a current remark, as applied to Charles Darwin, that he fur-
nishes in himself one of the finest illustrations of “ development,”
and thus of the truth of his own theory, that can be cited. Far
more pointed, however, is the pleasantry of Haeckel, when, refer-
ring to the grandfather of Charles as entertaining the germs of his
_ grandson’s philosophy, and noting the striking circumstance
that his father, though a respectable physician, exhibited no signs

GENESIS OF MAN. 9

of having inherited these intellectual characteristics, he cites the
case as a good example of “atavism,”’ and remarks that “ Erasmus
Darwin transmitted, according to the law of latent inheritance, de-
finite molecular motions in the ganglion cells of his cerebrum to
his grandson Charles without their manifesting themselves in his
son Robert.”

The importance of Erasmus Darwin’s views, however, mixed as
they were with some vagaries and unbalanced speculations, was
slight as compared with that which we must ascribe to those of
Goethe. In his various essays and writings on “ Natural Science ”’
in general (1780), on Comparative Anatomy and Osteology (1786),
on the Metamorphoses of Plants (1790), and in later works, he has
wrought out a philosophy of organic life, which, when carefully
analyzed and translated into the terminology now adopted, is found
to contain, in their most general and fundamental form, the essen- ,
tial principles of the Darwinian theory of development. A few
passages will illustrate this. In 1706 he wrote: “All the
more perfect organic natures, under which we see fishes, amphib-
ians, birds, mammals, and, at the head of these last, man, are
formed according to one original type (Uréi/d), which in its dura-
ble parts only deviates more or less, and is still daily being im-
proved and transformed through propagation.” It is from this and
other passages in which Goethe establishes his doctrine of an origi-
nal type or image, which varies only slightly and in detail and not
in plan, that the modern adherents of the theory of fixed types seem
to have derived their chief arguments. Cuvier must have been con-
versant with Goethe’s scientific writings, and he may have drawn
largely upon them in founding his celebrated system of classifica-
tion. But like some other great works that have become author-
ity, those of Goethe are found, in some things, to admit of two in-
terpretations, and to supply texts looking more than one way. The
above passage, taken in connection with others, is now seen still
more clearly to give countenance to what is now the powerful rival
of the doctrine of types: viz., the doctrine of descent. In another
place he says: “An internal original community (Gemezzschaft) lies
at the bottom of all organization ; difference of form, on the contrary,
arises from the necessary relations to the external world, and we
may, therefore, with right assume an original, simultaneous varia-
tion and an incessantly progressive transformation, in order to com-
prehend the at once constant and deviating phenomena.”

ife) GENESIS OF MAN.

To further explain this paradox he assumes two independent
forces or impulses, working harmoniously together in nature, an
internal formative impulse (zzzerer Liuldungstrieb), and an external
formative impulse (ausserer Bildungstricb). The former of these he
also, in different passages, designates as the specific force (Specifica-
tionstvicb) and as the centripetal force ; the latter, on the other hand,
he calls the modifying force or impulse of variation ( Variationstrieb,
and the centrifugal force. He also uses the term metamorphosis
in a general (phylogenetic) sense as applied to the changes that
take place in species and genera rather than in individuals. The
following passage contains the kernel of this entire portion of his
philosophy: “The idea of metamorphosis is like that of the wes
centrifuga, and would lose itself in infinity were there not a check

offered to it; this check is the specific force (Speczficationstricb), the
stubborn power of permanency (zahe Leharrlichkeitsvermigen) of
whatever has once become a reality, a wes centripeta, which in its
deepest foundations can possess no externality.”

If, now, we translate Goethe’s internal formative impulse, specific
force, or centripetal force, by the modern term /eredity, as we un-
doubtedly may, and his external formative impulse, modifying force,
or centrifugal force, by the modern term adaptation, as we may
still more clearly do, we shall have, in Goethe’s philosophy of life,
neither more nor less than the essential glements of the modern
doctrine of descent.

Of course, nothing is here found but the general principles; the
mode and the examples could not have been furnished in Germany
when Goethe wrote.

Haeckel, however, is abundantly justified in pointing to Ger-
many’s greatest genius as having long ago given utterance to the
most radical of his own doctrines and that for which he has re-
ceived the severest animadversions, when, in the passage first
quoted, he places man at the head of the mammalian class. And
yet, who had thought of assailing Goethe with the charge of deriy-
ing man from the apes!

With almost equal justice does Haeckel claim that, in the follow-
ing and other passages, Goethe has not only declared the genea-
logical relationship of the vegetable to the animal kingdom, but
has furnished the nucleus of the unitary or monophyletic theory of
descent. ‘ When we consider plants and animals in their most im-

GENESIS OF MAN. II

perfect condition they are scarcely to be distinguished. This much,
however, we may say, that those creatures that now and then ap-
appear, having relationships with plants and with animals difficult
to separate, perfect themselves in two opposite directions, so that
the plant at last glorifies itself in the tree, durable and fixed, the
animal, in man, with the highest degree of mobility and freedom.”

_ The ambiguity of Goethe’s language is due to the profundity
and high generality of his ideas, coupled with a certain poetic
vagueness so indispensable to his genius. In the former quality,
though not at all in the latter, one is reminded of that profound
and comprehensive analysis which, with all the materials of that
later date (1866), and with the power of logic characteristic of
England’s foremost philosopher, Herbert Spencer, in his Lzology,
(vol. 1, ch, xi., and xii.), has made of these same principles; a
treatise, | may add, which Haeckel has indeed recognized,? but
upon which he could scarcely have failed to place more emphasis
if he had been thoroughly acquainted with it.

Quite different in method and character from Goethe’s contribu-
tion to the theory of transmutation and descent was that of La-
marck. Whatever his philosophy may have lacked in profundity,
it was not open to the charge of ambiguity. All its shortcomings
were amply compensated for by the wealth of illustration and the
multiplicity of facts drawn directly from nature, which, as a life-
long naturalist, he was able to bring to its support. In this respect
(and this is after all the chief consideration), the now celebrated,
though long neglected, Fhilosophie Zoologique is alone, of all the
works that had preceded it or were contemporary with it, worthy
of a serious comparison with the Origin of Species or the Descent
of Man. And it is certainly a remarkable coincidence and may
have for some readers, if no other, at least a mnemonic value, that
the Philosophie Zoologique and the Origin of Species were separated
by the space of just half a century, the former appearing in 1809,
the latter in 1859. The interest of this circumstance is still further
heightened by the fact that Charles Darwin was born in the year
1809, the same in which the great precursor of his own works like-
wise issued into the world; as if its subtle influence had wafted
across the channel and breathed its mysterious affatus into the
nostrils of the new-born herald of its principles!

3 Schépfungsgeschichte, 5 Aufl. pp. 106, 657.

r2 GENESIS OF MAN.

The dim intimations and scattered glimpses of Goethe and of
Dr. Darwin were insignificant in comparison with the lucid illus-
trations and systematic arguments of the great French naturalist.
After so many years of assiduous study Lamarck, as it were, but
copied his conclusions from the pages of nature where facts stood
forth like letters ina book. Yet none the less credit to his intel-
lect, for was not this same book sealed to his great contem-
porary, Cuvier, who knew its alphabet equally well ? And is it not
sealed to many to-day? The truth is that for the first time the
causal and essentially rational type of mind had been joined in the
same individual with those other qualities which impel to the pa-
tient investigation of facts and details ; rare combination, so success-
fully repeated in the intellectual constitutions of Charles Darwin
and Ernst Haeckel.

When we compare, from our disinterested standpoint in America,
the great chef d’ euvre of Jean Lamarck, its systematic execution,
its definite, avowed purpose, and its vast array of proofs from the
only legitimate source of argument, with the various writings of
Goethe containing his views on this subject, arranged with no sys-
tematic order, having no well defined purpose, evincing no clear
conception of nature’s means or methods, and manifesting a com-
paratively scanty acquaintance with particular cases by which the
laws under discussion are to be illustrated, we cannot fail to per-
ceive, in the circumstance of Haeckel’s placing his own country-
man before the son of a rival nation, in his estimate of the relative
labors of the two pioneers of evolution, a trace of that almost
inevitable national bias which lurks in regions of the brain inac-
cessible to the invasion even of exact science. The essential
incongruity between the first and last parts of the following passage
will be apparent to all. “At the head of the French natural
philosophy stands Jean Lamarck, who, in the history of the doc-
trine of descent, next to Darwin and Goethe, occupies the first place.
To him will remain the immortal glory of having for the first time
brought forward the theory of descent as an independent scientific
theory and established it as the natural philosophical foundation
of all biology.” He certainly ascribes to Goethe no such “im-
mortal glory”’ as this.

There is but one distinct element in Darwinism that is not also
found in Lamarckism. This is the important recognition of the

GENESIS OF MAN. 13

law of competition among living organisms as a factor in develop-
ment; that principle which Darwin so forcibly expresses by the
phrase “struggle for existence.” Lamarck does indeed recognize
this “struggle” and the influence it exerts in preventing the un-
checked multiplication of any one species from rendering the globe
uninhabitable to others. But he seems to regard this as a wise
precaution and calculated “to preserve all in the established order.”
In other words, he recognizes it as a sfatical but not as a dynamical
law. He fails to perceive its influence in transforming species.

It is the full appreciation of this element that constitutes the real
strength of Darwinism; it is the key-stone of the arch of the
descent theory, for the discovery and successful illustration of
which too great praise cannot be awarded to the English naturalist.
But every other important principle embraced in his Ovigin of Spe-
cies was also contained in more or less definite form in the Phzlo-
sophie Zoologique.

The failure of Lamarck’s views to gain the ascendancy so rapidly
attained by those of Darwin, was due to a variety of causes. First
among these was the general fact that the state of science and pub-
lic opinion had not, at his time, sufficiently advanced for the gen-
eral reception of that class of ideas ; and any estimate of Lamarck’s
works which leaves out their silent, leavening influence upon cer-
tain classes directly, and thence indirectly upon society at large,
is too hastily made and fails to do them justice. Next in impor-
tance, in preventing the early spread of Lamarckism, comes the un-
fortunate omission, above alluded to, to grasp the great law of bio-
logical competion in its dynamic form. As a third influence may
be ranked the somewhat direct and undiplomatic method of La-
marck, which never consulted the policy of what he wished to say
or courted the approval of high authorities. Every truth in his
possession was put forward in the most direct and naked manner, re-
gardless of the shock it might produce upon a world still groping in
the murky atmosphere of teleology. Stilla fourth element of weak-
ness in the Lamarckian philosophy was the inadequate emphasis
which he laid upon the most important of all his principles, that of
heredity, and the correspondingly undue importance ascribed to
habit, to use and disuse, as a direct agent in the modification of or-
gans. The real failure here was to grasp the true connection and
cooperation of these two principles. In short he seemed but dimly

14 GENESIS OF MAN.

to perceive the manner in which the inheritance of. slight variations,
howeyer produced, and their transmission to successive generations,
brings about, in the course of time, the transformation of some, and
the extinction of other species. It is the clear conception and forci-
ble presentation of this principle and its happy combination with
that of the perpetual competition going on in nature, that gives
to Darwin’s exposition that air of extreme probability and that
power of universal conviction so characteristic of his works.
The importance of this distinction between the methods of the
two naturalists in expressing this conception may justify me in
borrowing a few very appropriate terms from the 4zology of Her-
bert Spencer for its better illustration. We may then say that
while Lamarck seemed clearly to comprehend the influence of the
environment (milieu) upon the organism, and to attribute the results
to this as the one great and sufficient cause, he failed on the one
hand to take in the full scope of the environment, and on the other
to conceive of all the susceptibilities of the organism. In his
conception of the former he inadequately, if at all, appreciated the
organic element, the influence of one organism upon another ob-
jectively considered as a modifying force. In his notion of the
organism and its susceptibilities he laid too great stress upon the
principle of “ direct equilibration,’ and comparatively little upon the
far more important one of “ zzdirect equilibration.” To the readers of
the Philosophie Zoologique it seemed a crude, to many a ridiculous,
explanation of the length of the fore-limbs and neck of the giraffe,
that they had become elongated by perpetual attempts to reach
the branches of trees that lay beyond the reach of other animals;
and while he admits that this could not have been accomplished
by the efforts of any single individual, and ascribes it to a series of
cumulative efforts through many generations, thus clearly recog-
nizing and expressly affirming the influence of heredity, he yet
fails to show the way in which this influence must have been ex-
erted, its #zodus operandi. He does not say, for example, that the
great elongation referred to was initiated in some remote ancestor
by some slight variation in this direction, either accidental or per-
haps due to the animal’s efforts; that this variation, proving ad-
vantageous and being transmitted to a numerous progeny, rendered
their chances of survival in critical periods greater than those of
such as possessed no such peculiarity ; that this power of survival,

GENESIS OF MAN. 15

due to this inheritable peculiarity, became thus a constant force
which, through the interbreeding of those possessing it, tended to
increase this variation, until in the course of generations it resulted
in differentiating the giraffe in the special attributes of length of
cervical vertebre and of anterior limbs, and in giving it its present
anomalous position among antelopes. Instead of this, Lamarck says:
«With reference to habits it is curious to observe their results
in the peculiar form and figure of the giraffe (camelo-pardals).
It is known that this animal, the tallest of the mammals, inhabits
the interior of Africa, and that it lives in places where the earth,
almost always arid and without herbage, compels it to browse
upon the leaves of trees and to be continually exerting itself to
reach them. From this habit, long maintained in all the individ-
uals of its race, it kas resulted that its fore-limbs have become
longer than its hind ones, and that its neck has become so much
elongated that the giraffe, without rearing upon its hind feet ele-
vates its head and reaches to the height of six metres, (nearly
twenty feet).”* It will be observed how in this reasoning (and it is
so throughout), Lamarck passes from the observed fact directly to
the original cause, leaving out the intermediate steps which it is
necessary to supply in order to conceive of the manner in which
the results are produced. Now, it is precisely this part of the ar-
gument that mankind in general require before they are willing to
give in their adhesion to a theory. They say: “ it all looks plau-
sible enough, but you fail to show us ow it actually takes place.”
As in his illustrations, so in his general “laws,” Lamarck fails to
grasp the principle of Natural Selection. His first great law is
expressed in these words: “In every animal which has not passed
the limit of its developments, the frequent and sustained use of
any organ little by little strengthens, develops, and enlarges this
organ, and gives it a power proportionate to the duration of this
exercise ; while the constant failure to use such organ insensibly
enfeebles and deteriorates it, and progressively diminishes its capac-
ities, causing it finally to disappear.”> His second law is as fol-
lows: ‘All that nature has caused individuals to acquire or lose
through the influence of the circumstances to which their race has
been long exposed, and consequently through the influence of the

4Phil. Zoo., Tome 1, p. 254. Paris, 1873.
5 Loc. cit., p. 235.

16 GENESIS OF MAN.

predominant exercise of any organ, or through that of a constant
failure to exercise any part, it preserves through inheritance (gévé-
ration) in the new individuals that proceed from them, provided
the changes acquired be common to both sexes, or to those which
have produced these new individuals.’’®

Whatever may be lacking in these two laws, there is certainly
contained in them a clear expression of the two prime factors of
the theory of descent: viz., heredity and variation; or, as Darwin
frequently expresses it, “ descent with modification.”” The elements
of availability alone are wanting; those working principles by
which the theory was to be erected into a perfect system and its
machinery set into running order.

A grand stride had been made, the doctrine of fixity of species
had received a fatal thrust, the special creation hypothesis was un-
dermined, teleology thenceforth was in organic nature doomed.

A fifth and last element of weakness in the Lamarckian philoso-
phy may be enumerated, one which Haeckel justly sets down to
the greater credit of the illustrious author as indicating how far he
had outstripped the intellectual progress of his age, so that it was
practically impossible that his views should have been accepted in
his own day. ‘This consisted in the acceptance and express enun-
ciation of two doctrines which are still to-day deeply involved in
controversy, even among the most advanced scientific men of our
times; that of spontaneous generation and that of the szuzan ances-
try of the human race, embracing in the latter the extreme theory
of the development of the mind parz passu with that of the nervous
system and the brain, and carrying it out to the logical consequence
of denying the freedom of the will, in the current sense of the
phrase. These were clearly, in Lamarck’s day, shocking and atro-
cious doctrines, and it is doubtless to these chiefly that is to be
attributed the neglect of his great contemporary, Cuvier, to give
the Philosophie Zoologique as much as a passing notice in his report
on the progress of natural science; as well as the rebuke of his
philosophical views which he saw fit to introduce into his “ eloge”’ (?)
of the great scientific labors of Lamarck. He little dreamed that
when these utterances should have been forgotten, and the works
of Cuvier consigned to the musty shelves of antiquarian libraries,
the humble effort which he had first disdained to notice and after-

6 Loc. cit.

GENESIS OF MAN. /

wards noticed with a reproach, would emerge from its long obscur-
ity, and, in new and modern dress, find its way to thousands of book
tables, as the classic foundation of a great progressive philosophy.

With regard to Lamarck’s views on the subject of spontaneous
generation, it is due to him to’say that he did not espouse any of
the crude conceptions which had been maintained on the authority
of Aristotle among the scholastic metaphysicians. He repeatedly
asserts that it is only the most imperfectly organized beings that
could be directly produced by the forces of inorganic nature, and
while he could have had but a faint idea of the extreme imperfec-
tion of these lowliest creatures, still as only the /eas¢ perfectly or-
ganized could, according to him, become the products of spontaneous
generation, his careful language on this point completely exempts
him from the charge of entertaining gross notions about the origin
of life. Haeckel, with his intimate acquaintance with the lowest
known forms of organic existence, his #zonera, does not hesitate to
declare the necessity of a transition, at some period, from the inor-
ganic to the organic condition; nay, more, he believes that these
monera are directly evolved, by the mechanical agencies of nature,
out of inorganic carbon compounds, and that protoplasm, of which
alone these creatures consist, is the initial stage of organic life.
With Lamarck, as with Haeckel, it is the logical necessity, rather
than any empirical discovery, that renders this doctrine indispen-
sable as a starting point and first link in the chain of organic devel-
opment. As the latter justly remarks, unless we do this the natu-
ral explanation is given up, and there remains no alternative but to
fall back upon the supernatural. Herbert Spencer, too, indepen-
dently of his theory of physiological units, has felt the force of this
a priori argument, and has ranged himself on the side of complete
consistency. Neither need the teleologists exult at the apparent
overthrow, just now so imminent, of the results of Bastian’s experi-
ments. From such a result we shall only the better learn Zow na-
ture works, and no adherent of the doctrine of archigonia will the
less maintain that life must have had a beginning upon the planet.
Lamarck leans to the assumption of a perpetuul series of such be-
ginnings which are still going on in the present as in the past, a
constant play of the originating force. Haeckel admits as much
for protoplasm and for his szonera ; beyond this he says it does not
concern the theory of descent to go. Darwin, with his character-

18 GENESIS OF MAN.

istic diplomacy, never lifts the dark curtain that hangs between
the organic and the inorganic world.

Professor Haeckel is not only an original investigator, but also an
original thinker. Primarily a specialist and investigator of the
minute histology of living organisms, there is combined in his
mental constitution, along with this indispensable talent, a large
development of causality which renders it impossible for him to
stop with the mere elaboration of details and the simple accumula-
tion of facts. To him every fact is one of the terms of a proposi-
tion, and every collection of related facts becomes an argument,
while the sum total of his knowledge of those minute creatures
which he has made a life study constitutes in his mind a philoso-
phy. Hev-is at once an investigator anda philosopher. To the
former quality, his numerous monographs of the lower invertebrates
sufficiently testify. His monograph of the Radiolaria (with an atlas
of thirty-five copper plates), of the Geryonidae, of the Szphonopora,
but especially of the calcareous sponges, belong to the minutest
and most exhaustive histological researches of modern zoology.
In all these, but particularly in the last named, the author has con-
stantly before him a theorem to demonstrate. He expressly
avows that his investigations into the calcareous sponges were
undertaken with a view to an analytical solution of the problem of
the origin of species. He seems not to have feared thus to invite
the charge of having resolved, in this investigation, to verify the
argument of Darwin, the perusal of whose great work had induced
him to undertake it. Nor does he fail to prove all he hoped to do.
On the contrary, he claims to have overwhelmingly established all
the principal claims of his English contemporary. The objection
had been raised that the Darwinian theory did not rest upon a suf-
ficient body of observed facts ; that it was a mere plausible synthe-
sis from a too meagre analysis. Haeckel holds up his two volumes,
containing the results of his five years of indefatigable labor on
these lower organisms, and his atlas with its sixty carefully drawn
plates, all elaborated from the most abundant materials from all
parts of the world, and challenges the scrutiny of his scientific op-
ponents. The doctrine of the fixity and invariability of species, al-
ready reeling under the blows of Lamarck and Darwin, he claims, is
therein completely demolished. He proves that in this group of ant-
mals the number of genera and species depends altogether upon the

GENESIS OF MAN. 19

meaning which each naturalist may happen to attach to these terms.
He may class them all under one genus with three species, or under
three genera with twenty-one species, or under twenty-one genera
with III species, or under thirty-nine genera with 289 species, or
even under 113 genera with 591 species, according as his concep-
tion of genera and species be wide or narrow. In fact, the 591 dif-
ferent forms may be so arranged in a genealogical tree that the
ancestry of the entire group can be traced back to one common
form from which all the rest must have descended, undergoing the
modifications induced by the varying conditions of their existence.
This common ancestor Haeckel believes to be the Olyzthus.

Thus, the long respected and miraculously created dona species
is histologically demonstrated a myth.

Rising from the special towards the general, the Generelle
Morphologie may be next named. It was the first systematic
attempt to establish the theory of development from the or-
ganized facts of comparative anatomy. But the most popular, in its
subject matter and style, of the works of Professor Haekel is his
Natirliche Schipfungsgeschichte, consistiong of a course of lectures
upon the questions in general opened by the Origin of Species,
but containing the advanced views of the author, already re-
ferred to. This work is, therefore, of the highest interest to the
general public, and cannot be too strongly recommended. It is
divided into five parts designated by the author with the following
titles, respectively, each of which sufficiently characterizes its con-
tents: 1, Historical Part; 2, Darwinistic Part; 3, Cosmogenetic
Part; 4, Phylogenetic Part; and 5, Anthropogenetic Part.

His Anthropogeny or History of the Development of Man, to
which we wi!l now confine our attention more closely, is simply an
enlargement and expansion of the last part of the A/zstory of Crea-
tion. ‘The greatness of the theme required this, and no one who
carefully follows the author through this work will complain that
justice has not been done the subject. As may well be imagined
this work covers the most interesting field of investigation and in-
troduces the reader into the most mysterious penetralia of nature.
The charm of its diction, the fullness of its illustrations, and above
all the perpetual wonderland through which it leads, entitle it to
take rank at once among the most instructive and the most fasci-
nating works to which moctene science has ever yet given birth.

20 GENESIS OF MAN.

’

“The proper study of mankind is man.” And yet how tame
appear the most mysterious facts of human anatomy and physi-
ology, as taught to the mass of mankind, compared with the as-
tonishing revelations of comparative embryology and comparative
anatomy !

As already remarked, Haeckel is a philosopher as well as an in-’
vestigator. No German philosopher can be without his terminology.
Haeckel has his, and it remains to the future to decide whether the
ends of science are to be furthered by its introduction. It is at
least certain that to understand Haeckel one must understand his
terminology. Being much of it of Greek derivation, it undergoes
little change by transfer to the English language. In so far, how-
ever, as it is German, this difficulty is great, often, indeed, quite
insuperable. Everybody admits the inadequacy of some parts of
Darwin’s terminology. The best English expounders of his theory
have found themselves compelled to adopt other terms to convey
his ideas with the requisite clearness and force. I have already
referred to important improvements introduced by Herbert Spen-
cer before it was possible for him properly to arrange the new
biological laws under his universal system of cosmical principles.
That author has also, in addition to those before referred to, pro-
posed an excellent synonym for Darwin’s most important term,
“Natural Selection.?), Thiswheyecalls “sSurvivalv ofa then fittest
which, while it can never of course supersede the former, must be
admitted by all to bring to the mind far more directly, the idea
which it is desired to convey.

Haeckel has felt the need of some adequate terms to characterize
the two great classes or types of mind, which not only now, but in
all ages, have existed in a state of opposition or rivalry in the
world. No matter what questions might arise for solution bearing
upon the knowledge or progress of the race, there has always ex-
isted this sharply defined opposition growing out of these two
constutionally opposite mental types. Various popular appella-
tions have been employed from time to time, differing in different
countries and for different forms of agitation. None of these, how-
ever, have struck at the true psychological root of the phenomenon,
and the world has been long waiting for a thorough analysis of this
subject and the suggestion of a scientific terminology, based upon
this ground-law of the constitutional polarity of the human intellect.

GENESIS OF MAN. 21

That Haeckel has fully supplied this want I would not venture
to affirm, but that he has made an important contribution towards
such a consummation cannot be questioned. “If,” says he, “you
place all the forms of cosmological conception of the various peo-
ples and times into comparative juxtaposition, you can finally bring
them all into two squarely opposing groups: a causal or mechant-
cal, and a ¢eleological or vitalistic group.”

The first of these groups, by requiring every phenomenon to be
conceived as the mechanical effect of an antecedent true cause
(causa efficiens), necessarily erects a cosmogony that is bound to-
gether throughout by an unbroken chain of mechanically depend-
ent phenomena. Such a universe is a unit, and throughout its
domain there can pervade but one universal law. This all-pervad-
ing homogeneous law is the monzistic principle or force, while
the whole theory which thus conceives of the universe is termed
by Haeckel, indifferently, the monzstic, and the mechanical theory
of the universe. Only those minds that are imbued with this con-
ception as a fundamental quality of their cerebral constitution are
capable of appreciating, or of subscribing to the Darwinian and
Lamarckian philosophy, which is simply the monistic principle
applied to biology. This class has formed in all ages and countries
the progressive and reformatory element of mankind.

The teleological or vitalistic group, on the other hand, conceive
of all phenomena as produced by a power either outside of nature
and acting upon it, or consisting of Nature regarded asa conscious
intelligence, and which, in either case, directs everything for an
ordained purpose or end (causa finals). This recognition of a
cause independent of phenomena renders the operations of nature
dual, and is designated by Haeckel as the dualistic conception,
and the body of such conceptions as the dualistic philosophy. All
teleological conceptions are, of necessity, dualistic, just as all causal
conceptions are necessarily monistic. The distinction between teleo-
logical and theological conceptions vanishes as soon as we Class
the pantheists among theologists. ‘This class is the great conser-
vative element of mankind, who, looking upon nature as under
the control of Omnipotence, logically resign all effort either to do
or to know into its hands.

Haeckel also employs the term dystelcology in antithesis to
teleology, and frequently uses it as a general term to designate
the monistic or mechanical philosophy.

GENESIS OF MAN.

N
bo

The entire body of principles embraced in the Lamarckian, Dar-
winian, and Haeckelian philosophy, when regarded as having passed
through its hypothetical and theoretical stages, takes the form of a
science, and receives the very appropriate name, History of De-
velopment (Entwickelungsgeschichte), a term adopted by Von Baer
and applied to embryonic development, but extended by Haeckel
to embrace also the secular development of specific forms. This
twofold application of the term History of Development, suggests
the natural division of the science into its two great departments.
The first of these is essentially that of Von Baer, and treats of the
progress of the individual organism from the earliest embryonic
condition throughout the numerous successive stages and trans-
formations through which it passes until it arrives at the perfect
state. Properly it does not stop at birth, but continues through
life, during which, in many creatures, very important metamorphoses
take place. This division of the History of Development is de-
nominated Oxtogeny. The other grand division, which treats of
the development of present living forms out of antecedent forms
through the influences of heredity (Vererbung) and adaptation
(Anpassung), is termed Phylogeny,a term derived from the Greek
word gddov, a race.

It is to this latter branch of the History of Development that
the attention of progressive minds has been heretofore almost ex-
clusively directed, and the arguments of Lamarck and Darwin have
been chiefly drawn from considerations of comparative anatomy,
of geographical distribution, and of paleontology. The powerful
re-enforcement which it has now received from ontogeny was quite
unexpected, and the astonishing uniformity with which the onto-
genetic facts support, confirm, and corroborate the phylogenetic
arguments, may be regarded as having placed the doctrine of
development beyond the stage of theory and speculation, and
established it as the first law of Biology.

Although the chief facts of ontogeny had been discovered and
recorded by Von Baer and others, a quarter of a century before, it
was left for Haeckel to first perceive and announce their relation to
the law of phylogenetic development, and to urge their irresistible
force as arguments for the theory of descent. Von Baer himself,
although he had erected them into a “ History of Development,”
seems but dimly to have realized the significance of these embry-

GENESIS OF MAN. 23

onic metamorphoses which he has observed and described, and as
recently as the date of the late Professor Agassiz’ public lectures,
is quoted by him in a private letter as still adhering to his doctrine
of types, and protesting against that of descent from the apes.’

Anthropogeny, or the Genesis of Man, considers all the argu-
ments, both from ontogeny and from phylogeny, 1n support of the
assumption of the descent of the human race in a direct line from
the lower animals, shows throughout the length of this line what
creatures now existing upon the globe or found fossil in the rocks,
stand nearest to this line of descent, and aims to trace the pedigree
of the being who is the present undisputed lord of the planet back
to the lowest amoeba, and even to the moner. Haeckel does not
stop with the ape, with the amphioxus, or even with the ascidian.
Guided by the Ariadnean clew of ontogenesis, he pursues man’s
genealogy back through the labyrinth of primordial forms into the
cell, and thence still back until he loses it in protoplasm.

Standing, as man does, at the head of the animal kingdom, and
forming the last and highest stage of development upon the globe,
the history of his progress from the lowest form of organic exist-
ence must be co-extensive with that of all other beings. It differs,
however, from the history of development in general, in not being
concerned with any of the branches that diverge at various points
from the main anthropogenetic stem. This becomes obvious when
we commence to study phylogeny, but may be noted here as a
means of better appreciating the true scope of Anthropogeny.
A few illustrations will make it clear.

Not to speak of the entire vegetable kingdom which is lopped
off at the first stroke, we find, as we ascend the scale, that one after
another the great branches of the Zoophytes, of the Annelids (in-
cluding all the Articulates and the Echinoderms), of the Mollusca,
of the Fishes, of the Reptiles, of the Ungulata and Cetacea, of the
Carnivora and Rodentia, and of many other less important groups,
are successively passed by and left behind; thus obviating the ne-
cessity of following out the special genealogy and development of
each of these complicated divisions of natural history. The his-
tory of development of man pushes right on, taking such notice
only of divergent trunks as is necessary to fix with certainty the
position of his line of march.

7 Since the above was written, the death of Von Baer has been announced. His
last effort was in the nature of a systematic attack on Darwinism.

24 GENESIS OF MAN.

IHL.
ONTOGENESIS.

HE primary law of ontogenesis and that which connects it
Ak with the modern theory of development, is founded on the
discovery of Von Baer, that the different successive stages of the
embryonic development of the higher animals bear a singularly
close resemblance to certain lower animals in their adult state, and
that the embryos of many animals, and of man himself, in their
earlier stages, are scarcely distinguishable from one another. This
fact, as already remarked, was carefully studied by Von Baer, and
the successive stages of embryonic life systematically compared
and co-ordinated. In his great work on the Astory of Develop-
ment of Antmals, (1828-1837), that distinguished embryologist has
given to the world the results of his exhaustive investigations. In
this work he announces that the theory of types founded by Cuvier
in 1816, upon the facts of comparative anatomy, is confirmed by
those of embryology, and shows that the process of development, .
which is the same for all the animals of any of the four types, is
different from those of different types.

Haeckel does not gainsay the general truth of this statement,
but simply shows that it cannot be used as an argument against
the theory of descent,as Von Baer’s investigations were confined to
fully differentiated animals of each type, and not extended to the
then little known Amphioxus and Ascidians, which later researches
have shown to constitute transition forms uniting two types. Be-
sides, as we shall see, however different the course of development
of different animals may be, the embryos of animals of higher
types pass through phases identical with the adult forms of some
of the lower types, though not of cthers, showing that the four
types of Cuvier and Von Baer—Radiates, Articulates, Mollusks
and Vertebrates—can neither be regarded as co-ordinate, nor as
regularly subordinated to each other. And this is not all: Von
Baer’s own facts, and those of many embryologists, show that there
must be another type added to these four ; viz, the Protozoa, and that
from this the course of both phylogenetic and ontogenetic develop-
ment has been through the Worms directly to the Vertebrates, leay-
ing the remaining types untouched. It seems, therefore, simply

GENESIS OF MAN. 25

that the different branches of the main stem have in our time
spread so widely, and become so far differentiated by adaptive in-
fluences, that even their embryos have lost many of the original
traces of relationship. The important fact remains that within the
vertebrate type, as within other types, the embryonic stages cor-
respond with wonderful accuracy to the successively ascending
classes and orders established for that type.

The law of Von Baer, expressed in the most general terms, as
laid down by himself, is in these words: “ The development of an
individual of a definite animal form is determined by two relations:
first, by a progressive development of the animal body through in-
creasing histological and morphological differentiation (Sonderung);
secondly, through simultaneous progressive development from a
more general form of the type to a more special. The degree of
development of the animal body consists in a greater or less
amount of heterogeneity of the elementary parts and of the indi-
vidual components of a composite apparatus; in a word, in the
greater histological and morphological differentiation. The type,
on the contrary, is the fundamental relation of the organic elements
and organs.”

Upon this important law, Haeckel puts the new interpretation
that the “type” of Von Baer is the representative of the law of
heredity of Darwin, (the vis centripeta of Goethe), while the « degree
of development” means neither more nor less than his law of
adaptation (Goethe's vis centrifuga).

The parallelism which is found to exist between the facts of
ontogenesis and the facts of phylogenesis, between the embryonic
forms of higher, and the adult forms of lower, organisms, is one of
the most astonishing discoveries which science has ever made.
It is one which would have been least likely ever to be reached
by conjecture or by any form of @ priori reasoning. There was
but one possible mode of reaching this truth, and this was by
long and patient investigation of the minutest objects and most
occult phenomena, without the aid even of a “ working hypoth-
esis.”

Such a truth must have a meaning. This meaning Von Baer
himself never realized and, when pointed out to him by others, never
accepted. Yet I venture to predict that no unbiased reader of
Haeckel’s Anthropogenw will any longer doubt the justice of his

26 GENESIS OF MAN.

conclusions respecting the significance of this marvellous co-inci-
dence. The believers in miracles, who refuse to accept this ex-
planation, will have discovered the most miraculous of all miracles.
The singular alleged action of Providence in stirring fossil shells
and bones into the earth, of which the mountains were made, “as
a cook stirs raisins into a pudding,” would be an intelligible phe-
nomenon compared with this. That a man should begin his
existence as an amocba, should subsequently turn into a worm, a
little later should become a /amprcy, later stilla fish, and after pass-
ing through amphibian, reptilian, monotreme, marsupial, lemurian,
and simian forms, should at last emerge with the human shape,—
this series of remarkable metamorphoses, if required to be explained
on the assumption that it is directed by the arbitrary will of the
Creator, would furnish a more fatal stumbling-block than even
the presence of those useless and usually deleterious rudimentary
organs, which all higher animals are found to possess. For
even if we can bring ourselves to comprehend how the Creator
may, for some inscrutable reason, introduce many arbitrary irregu-
larities into his handiwork, according as he may be actuated by
this or that caprice, we are still at a loss to understand how he
should wish to carry on a whole system of freaks in the embryo,
which have a manifest correspondence with the mature forms of
life known to exist upon the globe, unless there be some causal
connection between the two systems.. Nothing short of the most
complete abnegation, of reason, nay, of a strong effort to accept
the unreasonable, can prevent the mind, cognizant of these two
series of facts, from becoming thoroughly convinced that such a
dependence must subsist.

- The science which embraces both the ontogenetic and the phy-
logenetic development of life, the genesis of life in general, is called
by Haeckel Azogenia, a science, as he remarks, as yet scarcely
founded. The law which expresses the relation between the
facts of ontogeny and the facts of phylogeny is, therefore, the
fundamental law of dzogenia. Stated in the most direct manner,
this law is that “ phylogenesis is the mechanical cause of ontogene-
sis.” From a somewhat altered point of view, the same idea is
conveyed by saying that ontogenesis is a brief recapitulation of phy-
logenesis, or, that the history of the germ (Keimesgeschichte) is an
abridgment or epitome of the history of the race (Stammesgeschichte).

GENESTS OF MAN. Dy,

Mathematically enunciated, the germ-development becomes a
function of the race-development, so that every differentiation of
the latter carries with it a corresponding and consequential differ-
entiation of the former. This is the fundamental law of organic
development, the great biogenetic ground-principle, to which the
student of the history of development, whether of its ontogenetic or
its phylogenetic aspect, must continually recur. The law of
heredity, which Goethe calls “ the stubborn power of permanency in
whatever has once possessed reality,’”’ while it graciously yields to
the influence of surrounding circumstances‘and admits of progress,
nevertheless requires, with all the rigor of sovereignty, that every
step forward shall be taken through the established channels, and
with due respect for the most ancient forms. The human germ may,
indeed, develop and perfect itself in the highest form of organized
existence, but the old and time-honored fish-form and worm-form
and amoeba-form, nay, even the moner-form, must be respected, and
the proud man-germ must humbly bow to the inexorable decree of
Nature, and must undergo this manifold and repeated metempsycho-
sis, which in its strange reality eclipses all the dreams of Thales
and Pythagoras.

Phylogenesis, which is a cause, begins with the moner; onto-
genesis, which is a consequence, begins with the cell. For man,
as for all animals that have advanced beyond an extremely low
stage of existence, there is but one mode by which new individuals
of the race can be created and the race itself perpetuated, and that
is by the contact of two germinal principles having opposite sexual
polarities. Each of these principles is a simple cell. The male is
the sperm-cell, the female the germ-cell. Only by the union and
literal blending of these two cells can generation take place,

The cell is the lowest organized form of existence. It is also
the last term in the histological analysis of the tissues of the body.
An animal is ultimately nothing more than an organized assem-
blage of cells, a compound individual.

The moner is a lower form of existence than the cell, the low-
est known form, and may be distinguished as a wholly unorganized
and undifferentiated individual.

There are but two essential properties of a cell, a central zzcleus
and surrounding protoplasm. The only organization, the only differ-
entiation, is that which distinguishes these two substances. And

28 GENESIS OF MAN.

this is itself very slight. Chemically, they can scarcely be dis-
tinguished. Both consist of a carbon compound, containing a
certain proportion of nitrogen, and belong to the albuminous group,
of which all animal tissues are principally composed. The nucleus
is generally of a darker color, but sometimes of a lighter, and may
or may not contain in its centre a minute dot—wzcleolus. It also
may or may not be surrounded by a membranous envelope. This
is generally present in the cells of plants, while it is generally ab-
sent in those animals.

The form of cells differs according to the circumstances of their
existence. They are the most plastic and easily modified by ex-
ternal conditions of all organized beings, and therefore make the
best subjects for the study of the law of adaptation. Stationary
cells in a motionless medium are uniformly spherical. When sub-
jected to pressure they assume hexagonal, elongated, or compressed
forms, according to the nature of the pressure. Cells that are
active in a liquid medium have a portion of the matter composing
their outer parts extended into a caudal appendage away from the
direction of motion. In addition to the forms named, cells fre-
quently assume others, sometimes taking wholly amorphous shapes,
resulting from the particular conditions to which they may be sub-
jected. They frequently change their form, and this not only from
external influences, but in obedience to internal or subjective de-
terminations. Fora cell isa living creature. It possesses all the
essential characteristics of an organized individual. The only
functions necessary to characterize a living being are nutrition and
propagation. Both these the cell possesses. It grows by the
absorption of nourishment from the medium in which it lives.
Where this nourishment is not uniformly mingled throughout the
medium, but exists in the form of scattered solid particles, the cell
acquires the power to extend portions of its substance into tempo-
rary organs of grasping (pseudopodia), and thus to enclose and
devour its food. It thus improvisesa mouth and jaws on whichever
side it may need them, and feeds itself after the manner of another
animal.

The cell propagates, like many much higher organisms, by
division, or fission. It continues to take nourishment and to grow
until it reaches the limit fixed by heredity for its size, and then,
instead of growing larger or of ceasing to take food, it divides into

GENESIS OF MAN. 29

two distinct cells. Each of these then goes through with the same
process of nutrition and division, and so on.

But besides these two essential phenomena, which are common
to all life, whether animal or vegetable, the cell performs two other
truly animal functions. It possesses the power of locomotion, and
the faculty of sezsation. Cells with caudal appendages; called
lash-cells (Gezsselzellen), have acquired that form in consequence of
their independent activities in their liquid medium. Various other
forms are traceable to similar causes. As a proof of the posses-
sion by cells of a faculty of sensation, we have only to consider
the efforts of various kinds to obtain their food. Some are actu-
ally carnivorous, and show a certain degree of dexterity in captur-
ing their prey. They are, therefore, not only capable of feeling,
but, in a qualified sense, of thinking and of reasoning.

There is no essential difference between the sperm-cells and
germ-cells of higher animals, and the simple cells of which many
lower animals consist, and beyond which they never advance. We
can only say that among the infinitely varied forms of life we find
that while most creatures have developed into highly compound
states, and only revert to the original unicellular condition at the
beginning of each individual’s existence, there are still many crea-
tures that never progress beyond this primordial stage, and whose
entire existence is passed in the form and condition of simple cells.®
Among such creatures may be named the Amocbae, the Gregarinae,
the /nfusorta, etc. These animals, as well as those which consist
simply of an accumulation or aggregation of cells, such as the
Labryinthuleae, etc., and which form the second stage of develop-
ment, never rising above the cellular condition, are classed by
Haeckel, together with his Planacada, ina grand division or depart-
ment by themselves, and called Protozoa. A further ground for
this classification will be seen later.

According to the fundamental biogenetic law above stated, the
cell must be the primordial form out of which all more highly
organized beings, including man, have developed, since it is the
original stage of their ontogenetic development. And as there
still exist unicellular beings resembling the sperm-cells and the

8 A complete description, both popular and systematic, of all the unicellular organ-
isms known to exist, was published by Prof. Haeckel in 1878, entitled Das Prottster-
reich, of which he has kindly sent the writer a copy.

30 GENESIS OF MAN.

germ-cells of higher organisms, the deduction is warranted that all
higher creatures are the descendants of some form of these unicel-
lular beings. Considering the differences that may and do exist
even in cells, and in animals consisting of a single cell, Haeckel
is led to the conclusion that of all the unicellular creatures known
to science, the Azzoeba bears the strongest evidence of being the
original progenitor of the human race.

The history of the discovery of the human ova and spermatozoa
deserves a brief notice. In 1672, De Graaf discovered the Graafian
vesicle, which he supposed to be the ovum itself. In 1797, Cruik-
shank, Prevost and Dumas found and described the true ovules,
but failed to comprehend their real nature and importance. It was
left for Von Baer, thirty years later, to complete the discovery, and
place it before the world in its full light. Purkinje (1825) and
Wagner (1835) added important contributions in the discovery of
the germinative vesicle or nucleus, and the germinative dot or zz-
cleolus. The fact that the ova are simple cells could not be recog-
nized until after the founding of the universal cell-theory by
Schleiden (1838) and Schwann (1839). It was then perceived that
eggs themselves are cells, differing in scarcely any respect from the
cells of other tissues.

The discovery of the spermatozoa, or male seminal animalcules,
was first made by Leeuwenhoek in 1674, and confirmed by Louis
Ham in 1677. A long war arose between the so-called Avzzmalcu-
lists and Ovu/lists, the first of which believed that the animalcules
were the true and only germs of the future being, which simply
found in the ova a suitable #atrzx for their development, while the
latter maintained that the ova were the true germs, which were
only affected with a germinative impulse by contact with the sper-
matozoa. The real nature of this mysterious process has only
been clearly brought to light by the labors of more modern inves-
tigators, among the foremost of whom must be ranked Prof. Ernst
Haeckel, of Jena.

The ova of all mammals are identical in all essential character-
istics. They all possess both nucleus and nucleolus, are of a
spherical form, and about one-tenth of a line in diameter, and all
acquire at maturity a membranous envelope called the chorion or
zona pellucida. The egg of a mouse and that of an elephant can-
not be distinguished from each other or from the human ovum in
any respect. They are all simple cells.

GENESIS Of MAN. 31

The sperm-cells of mammals possess a no less marked similarity,
They are exceedingly small as compared with the germ-cells, and
possess long filiform caudal appendages. The chorion is wanting.
Their form may be divided into head, body and tail, but between
no two of these parts can there be said to exist any clear line of
separation. The head contains the nucleus surrounded by proto-
plasm or cell-substance, which is carried backward in gradually
diminished quantity, forming the remaining portions. It was not
until the year 1873 that it was discovered that these important or-
ganisms, like the female ova, were simple cells. This discovery is
in great part due to Prof. Haeckel’s own investigations.

We may now consider the immediate consequences of the union
of the sperm-cell with the germ-cell. The spermatozoon penetrates
the many times larger ovum, making its entrance through minute
pores in the chorion, and mingling at once with the germinative
matter of the cell. A remarkable change takes place. Two per-
fect cells with opposite sexual polarities have been drawn together
by their inherent affinities. They have met and their substances
have commingled. They literally blend into one individual. But
that individual is no longer a cell. The sperm-cell has lost its in-
dividuality and wholly disappeared. The nucleus of the germ-
cell has likewise entirely vanished. The entire interior of the
original cell has become a homogeneous mass of protoplasm, no
longer possessing any traces of organization. Only the chorion
remains to determine its original form. It isa case of retrogres-
sion (Riickbildung), of reversion to the lowest type of existence.
The human being who, as represented in sperm-cell and germ-cell,
stands on the plane of the amoeba and the znfusorium, has gone
back, on the union of these cells, to that of the szoner. As if
nature was not satisfied that any form of life should begin with the
cell, the second stage of existence, but required absolutely that
every being, no matter how high might be its destiny, should go
to the very foot of the scale and climb the entire distance, in order
that it might pass through every form that has belonged to its
whole line of ancestors.

From another point of view, this union and literal blending of
the male and female principles is not only of the highest intellectual
interest, but is calculated to awaken the most lively esthetic senti-
ments. Nothing more poetic or romantic has ever been presented

32 GENESIS OF MAN.

to the human fancy by all the fictions of the world than the mar-
vellous reality of this courtship of cells! The very fountain-head
of love (Urguelle der Licbe)is reached in the affinities of two cells!
The ruling passion of all ages has its ultimate basis in this new-
found physiological fact. When the march of science shall have
exposed the false basis upon which the present artificial code of
social life rests, and when the fears of those who can imagine
nothing better shall have been dispelled, then let the future Homer
of science sing, not the illicit loves of Paris and Helen, which
whelm great nations in untimely ruin, but the lawful wooings
and the heroic sacrifices of the sperm~cell and the germ-cell as
they rush into that embrace which annihilates both that a great
and advancing race may not perish from the earth! And here
there is no fiction, there is not even speculation. Both the plot
and details of this tale belong to the domain of established fact, —
and rest upon the most thorough scientific investigation.

The structureless form first assumed by the fecundated ovum is
_termed a cyzod, but from the circumstance of its being the onto-
genetic form, which corresponds to the moner, Haeckel has also
applied to it the systematic name of Monerula. In his system this
is the stage of germ-development which the moner, before its
further differentiation, had impressed upon all organic matter,
and through which all higher forms must consequently invariably
pass.

This cytod or monerula stage is, however, of short duration.
Very soon the homogeneous mass acquires a new nucleus, and
thus again assumes the character of a simple cell. This second -
cell-form is so similar to that of the unfecundated ovum that many
observers who had actually witnessed the cytod-form, on looking
again, soon after, and seeing only the primary cell-form, had dis-
credited their intermediate observations. It was not until the en-
tire transformation had been repeatedly witnessed through all the
steps of its progress, that the fact of such a strange transition be-
came established beyond a doubt.

The new cell, although indistinguishable from the old, possesses
an invisible element derived from the absorbed substance of the
sperm-cell which gives it the potential character of the parents.
The old cell, as such, was an independent living organism, capa-
ble of performing the essential functions of life, including that of

GENESIS OF MAN. 33

reproducing its kind; z. ¢., of dividing up into cells like itself, but
which could progress no farther. The new cell,on the other hand,
is the germ of a highly-organized being.

This is the second, or ovulum-stage of development which has
been impressed upon the germ by the amoeba stage of phyloge-
netic development. The human being is now an amocba.

The next step in the development of the fecundated germ con-
sists in a process of division which takes place in the nucleus.
This first divides into two, and the surrounding protoplasm ar-
ranges itself into two hemispheres so as to form a double cell.
Then each of these two nuclei, with its surrounding protoplasm,
goes through the same process, dividing the cell into four parts.
The same process is then repeated for each of these parts, and so
on, increasing the division in a geometrical progression, until the
entire contents of the chorion consist of a mass of closely-aggregated
minute cells.

The form which the fecundated egg has now assumed, is called,
from its resemblance to a mulberry, the M/orula, and constitutes
the third, or Morula-stage of development. It is merely a com-
pound form of the simple cell. Instead of one comparatively
large cell, it now consists of an aggregated society of small cells.
Prof. Haeckel has established a theoretical group of compound
amoebez, which he calls Syxamocbia, as the phylogenetic ancestral
form to which the W/orula owes its existence; but it has been shown
by the researches of Archer and Cienkowski into some species
of Cystophrys and into the Ladryinthulee, that these hypothetical
Synamochia have an actual representation in the fauna of the globe.
These creatures are found to consist of formless accumulations of
similar simple cells.

The fourth stage of germinal development is the Slastosphaere-
stage. Jt consists of a transformation of the MJorula, which is
brought about by the absorption of a clear fluid from the medium
in which it is situated, which collects at the centre and crowds the
cells outward, pressing them together until they are made to form
a single layer upon the inner surface of the chorion, and thus leav-
ing the whole interior filled only with the new liquid. The germ
is enlarged during the process, from its former diameter of about
one-tenth of a line to that of half a line. The cells now forming
this single layer have assumed a hexagonal shape, due to their

34 GENESIS OF MAN.

lateral pressure against one another. The new form is denomi-
nated the Blastosphacra or vesicula blastodermica, while the cellular
layer bears the name of germinal membrane (Ketmhaut) or blasto-
derm.

The blastosphaere is a stage of embryonic development which is
common to all creatures that have a higher organization than that
of the synamoebian societies of cells. In many of the lower forms
of life it becomes a stage of metamorphosis rather than of embry-
onic development, since these minute blastosphaeres lead independ-
ent lives for a time, as the larve of higher forms. This is the case
with the calcareous sponges, with many zoophytes, worms, ascidi-
ans and molluscs. Such larve are called Planule. They are
usually covered with cilia, which serve as aids to locomotion.
These facts alone would justify the believer in the dependence of
ontogeny upon phylogeny in maintaining that this stage had once
formed the highest plane of development, and that there had once
existed a race of creatures which, after passing through the three
preceding stages, completed their career as true blastosphaeres, and
that all higher organisms must, in that sense, be descendants of
such a race. Haeckel assumes such a group of creatures, which
he calls the Planaeada. ‘This hypothesis, however, was scarcely
necessary, from the fact that there are animals well known to
science which conform in their general structure entirely to this
stage of development. Many such creatures now exist, both in
the sea and in fresh water, consisting of a single exterior layer of
cells, surrounding a fluid or gelatinous interior, and usually pro-
vided, like the larval forms, with locomotive cilia. Especially may .
be mentioned the Syzura in the Volvocinae and the Magosphaera
planula. The latter was discovered and named by Haeckel, who
has carefully traced its development through the lower stages, and
proved the Planu/a to be its highest and mature condition. Such
an animal is, therefore, a true Flanaca, as strictly so as are the
members of Haeckel’s theoretical ancestral group of Planaeada.

To the philosophical embryologist, the blastosphaere-stage pre-
sents an extraordinary interest. Nothing could illustrate this
better than the remarkable utterance which it has elicited from Von
Baer himself, one of the few of his statements which possess not
only an ontogenetic, but also a phylogenetic significance. “The
farther we go back,” says he, “the greater agreement do we find,

GENESIS OF MAN. 35

even in the most different animals. We are thus led to the ques-
tion, whether at the commencement of development, all animals
were not essentially alike, and whether there does not exist for all
acommon primordial form? As the germ is the undeveloped
animal itself, so it may be reasonably stated that the simple blasto-
sphaere (Llasenform) is the common fundamental form out of
which all animals are, not only ideally, but historically devel-
oped.”

The next and fi/¢i stage of embryonic development is the most
important of all, as it leads us directly to the consideration of
Haeckel’s celebrated “Gastraca Theory.’ The ontogenetic form
is called the Gastruda, which differs in two important respects from
the Planula. Instead of a single cellular layer, as in the “latter,
the Gastrula possesses two such iayers, one immediately within
the other. These layers themselves differ from that of the Plan-
ula, in consisting of several rows of cells instead of one, thus form-
ing two distinct coats composed each of several layers of cells.
These two coatings are quite independent of each other, and may
be easily separated, which is not the case with the layers of cells
composing each coat. The two coats differ still further from each
other, in being made up of unlike cells. Those of the inner are
larger, softer, and darker colored than those of the outer.

The other important distinction between the Gastrula and the
Planula is the possession by the former of an orifice at one point
on its surface, through which it receives its nourishment, and
excretes refuse materials. This form of the Gastrvula-stage, how-
ever, it should be stated, cannot be identified in the higher verte-
brates. In man it is represented merely by a disc-shaped thicken-
ing at one spot on the spherical germ, and the formation there of
the two primary germinative layers which extend round into a sort
of sack, which is the unmistakable homologue of the typical Gas-
trula of the lower animals.

The process by which the embryo passes from the Planxula to
the Gastrula state, though simple, would be somewhat tedious, and
the reader must be referred for the details of this transition to
treatises on embryology, or to Prof. Haeckel’s own work.

An extraordinary interest attaches to this stage of ontogenetic
development, in consequence of its carrying the embryo across the
line which separates the Protozoa from the Mefazoa. WUaeckel in-
sists upon this as the primary division of the animal kingdom.

36 GENESIS OF MAN.

The Profozoa are not a co-ordinate department or type with the
Vertebrates, Mollusks, etc. They constitute a sub-kingdom, co-
ordinate only with the other sub-kingdom of JZefazoa, under which
these types all fall. To class the Protozoa among the Radiates
would be equivalent to placing the Cryptogams under the Endo-
gens ina botanical system. The reasons for this are purely onto-
genetic. The Gastrula possesses the two primary germinative
layers, which belong to none of the forms below it. The most
thorough embryological research has established beyond a doubt
the important fact that all the tissues of the body of every animal
that develops beyond that stage, are evolved out of the one or the
other of these primary layers. The Profozoa and the M/efazoa are
therefore separated by the broadest possible line of demarkation,
the former possessing no primary germinative layers, while the
latter are either composed of them or developed out of them. ~

The extreme importance of these cellular layers, therefore, be-
comes at once apparent, and it is upon the manner in which the
different tissues of the body are formed out of this simple building
material that the most patient and indefatigable embryologists
have been engaged during the past half century. It is found that
from the outer layer or exoderm are formed: first, the epzdermus
and organs arising from it (hair, nails, feathers, scales, etc.); sec-
ondly, the nervous system and the most important part of the
organs of sense; thirdly, the greater part of the flesh of the body,
the muscles; and fourthly, the skeleton of vertebrates; in short,
all the organs of locomotion and sensation.

Out of the inner layer, or extoderm, on the other hand, are de-
veloped first, the inner lining or epithelium of the entire cavity
of the body, together with that of all the glands and organs be-
longing to it, lungs, liver, etc.; secondly, the muscles of the in-
ternal vegetative system, including the heart; and thirdly, the cells
of the generative organs. ‘This last, however, is still open to some
doubt.

In consequence of these special functions performed by each of
the two primary germinative layers, the outer one has been called
the animal germ-layer (animales Keimblait), and the inner the vegeta-
tive germ-layer (vegetatives Keimblatt). The Latin terms exoderma,
dermophyllum, lamina dermats, and lamina serosa, have also been
applied to the former, and cxtoderma, gastrophyllum, lamina gas-
tralis, and lamina mucosa to the latter.

GENESIS OF MAN. 37

The Gastrula is a common larval form of many lower animals,
such as Sponges, Polyps, Corals, Medusae, Worms, Mollusks, and
Radiates. It is also a larval form of the two most interesting of all
animals for the history of development: viz., the Ascidian and the
Amphioxus. Many Zoophytes and sponges are indeed nothing
more in their final state than an aggregation or society of Gastru-
lae. They therefore constitute a compound Gastraea.

There is still another larval form belonging to this class which
possesses an almost equal interest with the Gastrula. This is the
Ascula. It belongs to the life histories of both Sponges and Me-
dusae, being developed out of the gastrula-form, and from it the
fundamental biogenetic law leads us back to the long extinct Pro-
tascus, or primordial sack, which was the ancient progenitor of
the Zoophytes. It is fixed to the bottom of the sea, having its
open end directed upward. No longer needing the cilia em-
ployed by the Gastrula as organs of locomotion, these are conse-
quently wanting. Its body consists of a simple sack or stomach,
whose walls are formed by the two primary germinative layers in
all their primordial simplicity.

The already famous Gastraea Theory of Haeckel is nothing
more than the simple application of his fundamental biogenetic
law to the Gastrula stage of development. By this law he is led
to the conclusion that at one period in the history of the globe, an
animal, having at maturity the form and organization of the Gas-
trula, and to which he gives the name of Gastraea, constituted the
highest form of organic development upon it, and that from this
primordial state of the two primary germinative layers, the process
of differentiation of organs proceeded, until the present complex
state of the animal kingdom has been reached, even as from the
embryonic gastrula-form the highest of living beings are now de-
veloped through this ontogenetic recapitulation. ‘The Gastraea,”
says he, “must have lived at least during the Laurentian period,
and sported about in the sea by means of its ciliated exterior coat,
in the same manner as the free-moving Gastrulae now do.”

The great interest which attaches to the Gastraea Theory, as
already remarked, arises out of the immense importance of the
primary germ-layers as the basis of all future histological develop-
ment. That which carries it further out into the field of specula-
tion, however, and thus in one way adds still more to its interest,

38 GENESIS OF MAN.

is the difficulty both in finding the true homologue in man and
the higher vertebrates generally, of the Gastrula of the Ascidian
and Amphioxus, and also in finding any good systematic represen-
tative of the ancestral Gastraea.

The rest of the history of the ontogenetic development of man
is the history of the differentiation of the two primary germina-
tive layers. The Gastrula stage has furnished, in these two layers,
the raw material for the entire future structure. By watching the
progress of growth in exoderm and entoderm, the successive tis-
sues of every part of the body may be traced to the highest degrees
of specialization. From this point of view that stage possesses an
interest far exceeding that of all those that have preceded it: forin
it is found the first truly specialized organ. That organ is the sto-
mach. The two essential functions of life are nutrition and repro-
duction. The one is the promoter of ontogenetic, the other of
phylogenetic development. But, as we saw in the cell, these two
functions are originally one, and that one is nutrition. Repro-
duction appears here asa mere continuation of nutrition. Nutrition
goes on to the limit of growth, when division takes place. Nutri-
tion is commuted into reproduction. Generation is phylogenetic
nutrition ; a truth which we should never have reached except by
the study of the lowest organisms. Nutrition, therefore 1s the one
essential function of life. The organ of nutrition is the stomach.
How significant, and yet how reasonable, that in the course of
development the first specialized organ should be the stomach, and
that the first creature possessing a specialized organ should consist
wholly of a stomach! Such a form is the Gastrula ; such a crea-
ture was the Protascus ; and such is the hypothetical Gastraea of
Haeckel.

The szvth stage of the ontogenetic development gives the human
embryo the form and organization of a worm. Our moral and
religious teachers have from time immemorial delighted in remind-
ing us that we were but “worms of the dust.” They should thank
science for demonstrating that they were right. We might almost
give them credit for an inspirational insight, did they not render
their sincerity questionable by the indignation they evince when
told that in the same sense that we are worms, we are also apes.

The first important step in the progress of embryonic develop-
ment, after leaving the Gastrula-stage, is the formation of two

GENESTS OF MAN. 39

additional germ-layers out of the two original ones. The exact
mode of their development is still under discussion among embry-
ologists. Haeckel believes that the original exoderm and ento-
derm secrete each a new layer of cells from its inner surface; that
is, from the surface of each which is contiguous to the other, so
that the two new layers lie against each other and separate the
primary by the thickness of both. It is, nevertheless, considered
that in the process the original constitution and identity of the
primary layers are destroyed, so that they have virtually resolved
themselves into four secondary germ-layers. The two outer layers,
however, now perform together the office of the original exoderm,
while the two inner ones take the place of the entoderm. This
division into four secondary germinative layers is the final division,
all the tissues, without exception, being formed out of these, as
they have in nearly every case been traced.

The names assigned by Von Baer and by Haeckel to these sec-
ondary layers have reference to the functions which they are found
to perform. Being all German in their etymology, they are diffi-
cult to render into English. The following may answer as such
an imperfect version:—Numbering them from the outside, the
first is called by Von Baer the skin or dermal layer (aztschicht),
and by Haeckel the dermo-sensory leaf or fold (Hautssinnesblatt).
The second is the muscular layer (Flesschschicht) of Von Baer, and
the dermo-fibrous leaf or fold (Hautfaserblatt) of Haeckel. The
third is Von Baer’s vascular layer (Gefassschicht),and Haeckel’s gas-
tro-fibrous leaf or fold (Darmfaserblai). The fourth, or extreme
inner layer, Von Baer has denominated the mucous layer or mem-
brane (Schlewmschicht), while Haeckel calls it the gastro-glandular
leaf or fold (Darmdriisenblatt). Space will admit of no further
following out of this interesting part of the history of embryonic
development.

All worms are composed of these four secondary germ-layers,
the lowest possessing them in their greatest simplicity. The popu-
lar idea of a worm is an elongated creature, consisting of many
joints or rings (somites), but this is only a compound state of the
primitive worm, each ring or joint constituting, zoologically, a dis-
tinct individual, and possessing morphologically, if not physiologi-
cally, all the characters of one. The primitive worm has but one
joint. Among the lowest of the worms are the Zurbcllaria, which

40 GENESIS OF MAN.

in many respects resemble the Gas¢rulae of some higher animals.
Like them, their body consists of a simple sack with only a single
orifice, and even possesses the ciliary organs of locomotion. The
great difference lies in the nature of the cellular layers composing
this sack. In the Zurbellaria these are the four secondary instead
of the two primary germinative layers. Haeckel reasons here to
an ancient primordial worm (Urwurm, Prothelmis), corresponding,
in all respects, with this stage of embryonic development in man
and the higher animals generally, and from which not only all
other worms, but all creatures higher than the worms, including
mankind, have descended. This worm-stage acquires an increased
interest from the circumstance that here the main trunk divides,
sending off the articulate branch in one direction and the mollusk
branch in another, leaving only the vertebrate stem. The embryo
assumes a certain bilateralness, the four secondary germinative
layers grow together at their dorsal median line, and a chorda
dorsalis is formed. This is the true Chordonium-stage. The em-
bryo now has the closest affinities with the larval state of the As-
cidian, which, strangely enough, though wholly devoid of a chorda
in its final state, has a well-defined one in its larval state. There is
another creature, the Appendicularia, which possesses a chorda
dorsalis throughout its existence, although in all other respects it
is a true worm, and belongs, with the ascidians, to the 7umzcata.
This animal is the true connecting link between the worms and
the vertebrates, between the ascidian and the amphioxus. The
hypothetical Ciordonium of Haeckel, the assumed ancestor of the
human race at this stage, and exact representative of the embryo
at this period of its growth, differs scarcely at all from the Appen-
dicularia. \t is the common ancestor of the Zunicata and the
Vertebrata.

From a worm, the embryo passes directly into a vertebrate. As
the ascidian larve, the appendicularia, and the amphioxus are
separated only by the smallest differences, although the two former
are clearly worms, while the latter is clearly a vertebrate, so the
corresponding transition stages in the embryo are distinguished
only by almost imperceptible shades.

The future man is now a vertebrate, but without distinct ver-
tebre. He is wholly without brain or cranial enlargement, with-
out a regular heart, without mouth, without limbs. He now be-

GENESIS OF MANE AI

longs to a great subtype of the Vertebrata, which Haeckel denomi-
nates the Acrania. This entire sub-type has now but a single
known living representative on the globe, the amphioxus’; but
Haeckel believes that a period existed when the Acrania greatly
prevailed over the Cramiofa, or cranium-bearing vertebrates, and
peopled all the seas and waters. This Acrania or amphioxus form
constitutes the seventh stage of ontogenetic development.

The next or ezghth stage is the Lamprey or Monorrhina stage.
The nervous system and the vertebral column begin to differen-
tiate. The spinal marrow undergoes a slight enlargement at its
anterior extremity, which is the rudiment of the brain. The
vertebral column begins to develop out of the rudimentary
chorda dorsalis. This does not take place by a gradual, simulta-
neous formation of all the vertebre along the line of the chorda,
but, singular as it may seem, by the formation of one vertebra
after another, beginning with the most anterior. This remarkable
process points unmistakably to the composite character of the
frame-work of every vertebrate body. Each vertebra of a verte-
brate, like each ring of an annelid, represents a distinct and once
independent unit of a compound organism.

The present Cyclostomata or Monorrhinae are believed by Haeckel
to be the sparse remains of a once great group of animals, which in
ancient times shared the possession of the globe with their gradually
increasing rivals, the Amphirrhinac, which had sprung from them
just as the embryo of every higher vertebrate passes from the con-
dition of the one into that of the other. The type of the former is
the still living Lamprey or /etromyzon. As the names imply, the
Monorrhinae have but one orifice for mouth and nose, which is of
a circular shape, and is used asa sucker, while the Aszphirrhinae
are provided with a pair of jaws and two nasal orifices, Excluding
the Amphioxus (Acrania) the entire vertebrate type (Cramzota) falls
under these two groups, the Amphirrhinae embracing all the higher
vertebrates, from the lower fishes upward.

From the form of the first of these groups to that of the second
the embryo now passes, and enters upon its svt stage of develop-
ment; it becomesa fish. But as zatura non facit saltum, this first

9 A second acranial animal, discovered near Peale Island, Morton Bay, Australia,
has very recently been reported to the Royal Society by Prof. W. Peters, who has de-
scribed it under the name of Apigomethys cultellus. This discovery is of the highest
interest’to naturalists.

42 GENESIS OF MAN.

fish-form is not that of a true Zé/eos¢, or ordinary bony fish, but of
a Selachian. Indeed, the higher fish-form is never attained, but the
embryo skims along at the bases of the great ichthyic and amphi-
bian branches, without becoming at anytime a true fish or a true
Batrachian. This is a very significant fact, and one which, while it
is easily accounted for by the general theory of descent, forms at
the same time a powerful ontogenetic argument for the truth of
that theory. For the typical representatives of any great group
exhibit only the extremities of greatly differentiated branches remote
from the parent stem, and it is not to be expected that in the
corresponding embryonic forms of animals higher up the stem we
should see anything but copies of those forms which existed prior
to, or at the commencement of, ramification, and which are conse-
quently within the common line of descent of both.

Some will, perhaps, regret that their ancestors should have been
worms, while they cannot count in their pedigree either the bee or
the ant; others may not feel flattered to be informed of their close
relationship with the frog and the toad; but few, I think, will be
sorry to learn that their forefathers were not reptiles, though this
fact precludes the more pleasant thought of claiming relationship
with the birds; for birds, with all their grace, beauty, and inno-
cence, are neither more nor less than transformed reptiles.

The human embryo passes along the base of the Batrachian
branch and through the Sozwra (thus saving its tail) and so keeps
quite aloof from the whole race of lizards, snakes, turtles, etc., and
a fortiori, of birds. The unborn man is first a Selachian, then a
Lepidosiren, then a Siren, and finally a Triton. His first limbs are
fins, his first respiratory organs are gills, and his lungs are at first
fish-bladders. :

The ¢enth and last stage of ontogenetic progress is denominated
by Haeckel the Amnion-stage. This stage embraces not only that
of all true mammalian forms, but also takes in the two inter-
esting antecedent groups, the Monotremata and the Marsupiaha.
Haeckel establishes a hypothetical Protamnion, which he locates
in the Permian period, and which he claims to have been the
original progenitor of all the Azzzzofa, or amnion-bearing animals.
The distinguishing characteristic of this embryonic form, as the
name implies, is the beginning of the development of the impor- |
tant organ known as the amnion, which is simply a large extension
of the yolk-sack, and is filled with a nourishing fluid. This fluid

GENESIS OF MAN. 43

is gradually absorbed and appropriated by the embryo, and fur-
nishes a portion of its nutrition. Simultaneously with the amnion
is developed also another important organ, the Ad/antois, or pri-
mordial urinary sack. Both these organs are confined to the three
highest classes of Vertebrates (reptiles, birds and mammals). The
embryo now begins to manifest decided mammalian characteristics.
Already, the gills have disappeared, having become transformed
into jaws, hyoid bones, and otolithes: the heart has acquired its
four chambers, and the swim-bladders have been specialized into
lungs. For a while the uro-genital and excrementary orifices
empty into the common cloaca giving it the monotreme character.
Then, while the allantois is still present, a partition separates
these, making both open externally. This is the Marsupial stage.
Lastly, the allantois is transformed into a placenta, and the pure
mammalian stage is reached. Leaving the great branches of the
Carnivora and Rodentia on the one hand, and of the Ungulata and
Cetacea on the other, the embryo now passes through the various
phases of a Sloth-form, an Ape-form, and an Anthropoid-form ;
and, conditions being normal, emerges on the two hundred and
eightieth day of gestation with the form of a human being.

No one who experiences the least regard for natural truth, what-
ever views he may hold respecting the meaning of particular facts,
can contemplate so remarkable a series of phenomena as this, and
realize that he has himself once been the subject of such a strange
course of development, without being led into a train of reflection
which will open up to his mind broader and juster conceptions of
the universe.

At the same time it would be impossible to exaggerate the
degree of added strength which a popular acquaintance with the
bare facts of ontogenesis would impart to the hypothesis of devel-
opment or modern doctrine of descent, and thus indirectly to the
general conception of the law of universal evolution.

IBUE.
PHYLOGENESIS.

HE fundamental biogenetic law that ontogenesis is an abridged
ak repetition of phylogenesis, that the transformations through
which the individual passes during its ante-natal and post-natal ex-
istence in the brief period of its career, are a mere reflection of those

4A GENESIS OF MAN.

through which its race has passed during the long ages of its slow
development, and that the latter process is the strict physical and
mechanical cause of the former,—this deepest of all biological laws
Haeckel no longer treats as a ¢heovem requiring demonstration, but
employs it asa postulate by the aid of which all the most trouble-
some gaps left in the anthropogenetic series by the evidences of
comparative anatomy, paleontology, and geographical distribution
(chorology), are satisfactorily closed. Such gaps have existed along
the entire line, rendering it difficult and in many cases impossible
to trace it, and leaving so large‘a part of the whole theory of de-
scent a matter of conjecture, that 1t was easy for those so disposed
to point out unanswerable objections. But once admit the facts of
ontogenesis, and miracle alone, and this of the most incredible kind,
is the only alternative to the acceptance of the fundamental law,
which, candidly viewed in the light of these facts, bears every mark
of inherent probability. Not only does this law fill out numerous
voids and supply many wholly “ missing links” in the phylogenetic
chain, but it also confirms, in the most remarkable manner, nearly
every item of the evidence furnished by the other sources of proof
of the doctrine of descent.

Great, indeed, was the step which this doctrine took when the
remarkable revelation was made in the domain of comparative an-
atomy, that the Amphioxus possessed a chorda dorsalis, and that
the Ascidian larva contained an even more distinct trace or rudi-
ment of a vertebral column. Professional naturalists, without pre-
conceived ideas could no longer resist the inference that here was
the true zerus between the worms and the vertebrates. Consider
now, the almost crucial verification which this hypothesis received
when it was found that the embryonic stages of every creature
higher in the scale of being than the Amphioxus presents phases
identical with those of that animal and of the Ascidiae, that even
the human embryo has its worm-stage immediately succeeded by
its Chordonium stage, and this again by its Acranial stage; the
collateral proofs extending even to the germinative layers, and thus
rendering the correspondence complete and the inference irresist-
ible. Equally pointed illustrations might be drawn from many
other points along the line of common descent.

But valuable as is this class of evidence at these comparatively
advanced stages, it is still more so far down toward the dawn of

GENESIS OF MAN. 45

organic existence. For while in the former it only serves to
supply the omissions or verify the testimony of an array of pa-
leontological, anatomical, and chorological facts, in the latter it
stands alone as the sole evidence of a tangible character of the
development of living forms out of the primordial and unorganized
plasma of nature, and indeed from inorganic matter itself. These
ontogenetic stages have already been considered, and unavoidable
mention, made of many of the forms to which they correspond, and
whose stamp they bear.

The deeper problem of the origin of life on the globe is one
which strictly belongs to phylogeny, and one which Haeckel has
not hesitated squarely and boldly to meet. The doctrine of spon-
taneous generation, or archigonia, is by no means so simple as
many suppose, and is not to be settled either by the success or
failure to originate bacteria, diatoms, and monads, under certain
conditions, in organic infusions.

The only form of generation which has ever yet come within
the scope of human observation, and which, from the nature of
things, can ever be expected to be directly witnessed by human
eyes, is, of course, that wherein the offspring proceeds directly
from a known and distinct parentage. This form of generation is
called focogonia, and genesis itself in its widest sense is, therefore,
primarily divided into archigonia and tocogonia.

The exceedingly complicated subdivision of tocogonia must be
passed over, as we need consider here only the simpler but still
somewhat complex one of archigonia, or original spontaneous
generation. Although nothing is perhaps empirically known re-
specting this process, its existence as forming the first link in the
phylogenetic chain, possesses the highest degree of probability a
priort, which is not at all lessened by any empirical failures to sub-
ject it to the testimony of the senses.

The problem divides itself into two, which Haeckel considers
distinct and independent. The phenomenon assumed by the one
he calls plasmogonia, in which the genetic process is conceived as
taking place ina fluid containing organic matter, which is supposed
by some to be essential to the origination of life. The other form
of archigonia, on the other hand, conceives the process as taking
place in a medium consisting wholly of inorganic elements, and
Haeckel accordingly denominates this process auéogonia, 7. ¢., un-

46 GENESIS OF MAN.

aided self-generation. It will be observed that the great majority
of the experiments thus far tried, have been confined to the first
of these classes, or plasmogonia. If we now consider the second
class, or autogonia, we perceive that this also presents a two-fold
problem. It is either a process which, under certain rare and
favorable conditions, is going on at all times in some parts of Na-
ture’s domains, or it may be one which was only capable of taking
place at one period in the geological history of the globe, when
conditions existed which were quite different from those now
existing, and that all the life now found on the globe has descended
through the tocogonic process from the primordial organisms then
created.

To all these questions but one answer can be given; but this is
an answer which either must be given, or else the whole monistic
theory must be surrendered. The answer is that somewhere and
at some time the organic world must have developed out of the
inorganic.

This is all we really £zow, but this we do know just as well as
we know that the surface of the earth has undergone the changes
which geology teaches that it has undergone. One of three things
is certain: either organic life must have existed from eternity, or
it must have been created specially, or it must have had a natural
origin out of inorganic matter. The first of these contradicts all
the facts of geology and all our modern ideas of the cosmogony of
our system. The choice lies, therefore, between the other two,
and for the consistent dysteleologist there remains no alternative. °

Haeckel, however, is undoubtedly too hasty in many of his ©
sweeping assumptions respecting this problem, as for example,
that of the direct autogonia of his moners, such as Bathybius
Haeckelu of Huxley, who dredged it from the bottom of the
Atlantic, where it exists in vast quantities as a strange, unorganized
mass of living protoplasm. Even this would doubtless be too
great a satus for Nature to make. It is certainly far more in har-
mony with Nature’s processes generally, and with the whole tenor
of the monistic or genetic philosophy, to conceive that between
the two divisions of archigonia which he establishes, autogonia and
plasmogonia, there is in Nature a regular gradation, as throughout
the rest of her domain, and that she first develops the plasma, that
is, some combination of organic matter, consisting of the necessary

GENESIS OF MAN. 47

nitrogenized and carbon compounds in a high state of complexity
and instability, and then, as a mere continuation of a uniform pro-
cess, impresses this, first with the lowest and then with higher and
still higher vital properties. For life is unquestionably a product
of molecular organization.

While, therefore, inorganic matter must be regarded as the
primordial ancestor of all organized beings, the first stage in the
genealogical development of all living things, and hence also of
man, must have been some form of szoner. Haeckel enumerates
eight genera of moners now existing on the globe, and there can
be no doubt that there are many more still undiscovered, and their
extreme and absolutely structureless simplicity renders it highly
probable that they are really the first form of life which was
developed on the globe.

The direct descendants of the moners are undoubtedly the
various forms of amoeba. About the only observable differentia-
tion required to effect this transformation, is the development of a
nucleus in the interior of the protoplasmic substance of the former
creature. This change converts the cyzod into a true ce//, and such
is the character of the amoeba, a simple individual of the first
order. According to Haeckel, neither the moner nor the amoeba
can be strictly classed either with animals or with plants. They
belong, together with many other lowly-organized beings, such as
the Flagellata or \ash-cells, the diatoms and the rhizopods, to his
famous ¢ird kingdom the Protista. As moners, however, are the
lowest of all forms of life, he divides these into three classes,
animal moners, vegetable moners, and neutral moners. The first
class develop into the lowest animal form, the Protozoa ; the sec-
ond into the lowest vegetable form, the Protophyta ; and the third
into the neutral form, the Protista. He also speaks of animal
amoebe, and seems to regard these creatures more nearly allied to
animals than to plants. At least, he places both the moner and
the amoebz at the base of the animal scale, as the fst and second
terms of the phylogenetic series.

From the amoeba-group proceed the true Protozoa, which,
therefore, stand in the anthropogenetic line. Applying now the
biogenetic law to the Morula-stage of ontogenesis, we are able
to conclude that these animal amoebas, at one period in their his-
tory of development, formed societies or compound individuals

48 GENESIS OF MAN.

(Sv2amoebia), which therefore constituted the corresponding third
stage of development in the anthropogenetic line.

There must have next existed, as the fourth stage, a family of
creatures standing at the base of the protozoa, whose bodies con-
sisted of a simple, hollow sphere, the walls of which were formed
of a single layer of cells. These were the Planacada, and they
find their embryonic recapitulation in the blastosphaere stage.
These creatures are not yet so far extinct but that representatives
of them still exist in Haeckel’s Mogosphacra, in Synura, and in
other marine and fresh-water forms.

The gastrula-form of embryonic development, barely traceable
in the higher vertebrates, but common to both Amphioxus and
Ascidiae, as well as to many lower forms, is all there is to warrant
the assumption of a class of beings once peopling the waters of the
globe, whose bodies consisted of a simple sack, open at one end,
and formed of two cellular layers. These were the interesting
Gastracada, which have given to all the forms that have descended
from them the warp and woof of all their tissues, the primary ger-
minative layers. They must have developed directly out of the
Planacada, and form the ffti stage in the descent of man.

Ontogenesis ‘next points, as a szvti stage, to an extinct race of
primordial worms, Archelminthes, which originated from the Gas-
traeada by the formation of an intermediary germinative layer,
from which the two inner secondary layers eventually differen-
tiated. These creatures belonged to the lowest sub-division of the
worms, the Acoclomi, which, as their name implies, possess no cav-
ity of the body (coe/om) distinct from the sack-like stomach. They
are also without any vascular system, heart, or blood, but manifest
the first traces of the formation of a nervous system, the simplest
organs of sense, and rudiments of secretive and reproductive
organs. The typical representatives of the Archelminthes are the
Turbellaria, but they also closely resembled the parasitic Trema-
toda and Cestoda, which belong to the group Acoelomt. Thus is
man connected by blood relationship with the loathsome tape-
worm that infests his stomach!

Out of the Acoelomi were developed the Coelomat:, which, still
low in the scale, nevertheless possess a distinct coelom. The now
extinct race which effected this transition have been called the
Scolecida, and form the seventh stage of anthropogenetic develop-

GENESIS OF MAN. 49

ment. The precise interval which they seem to have bridged over
lay between the Zurbellaria and the Enteropneusta, the last of
which are represented by the well-known LBalanoglossus. From
this point the great articulate branch swung off, and a little higher
the important branch of the Mollusks.

To arrive at the ezghth stage, we are again compelled to resort
to the fundamental biogenetic law, and reason from the chordonium
stage of embryonic development of all vertebrates to an extinct
form, which must have possessed the rudiment of a vertebral col-
umn in the form of a chorda dorsalis as a permanent character of
its adult state. It would have been wholly impossible to say
whether this assumed creature should be placed in the department
of articulates, mollusks or worms, were it not for the flood of light
which the anatomy of the Amphioxus and the Ascidian has,
within the past few years, shed upon the whole problem.

The existence of such a chorda in the former of these animals,
and its presence also in the larval forms of the latter, are two facts
which point unmistakably to the type Vermes as the one which

_has furnished the transition to the Vertebrata. No creatures have
been found in any of the other types which afford the least intima-
tion of any such transition, and neither in the Protozoa, the Zoo-
phytes, the Echinodermata, the Crustacea, the Arthropoda, nor the
Mollusca, has any trace of a chorda dorsalis, either in the larval or
adult state, been detected after the most thorough examination.
The conclusion is, therefore, irresistible, that the sub-kingdom
Vermes and the class 7uzicata have furnished the true progenitor
of the vertebrates. This transition form itself has probably long
been extinct, but it has left lineal representatives in the Ascidia,
Phallusia, etc., which, while through long adaptation to a fixed
existence during their adult state they have lost their chorda, still
retain that distinctive character during their free larval state, as the
unquestionable ontogenetic representative of an organ which they
have inherited from their extinct chorda-bearing ancestor. This
ancient and primordial ancestor of the vertebrate sub-kingdom to
which so many facts, both of ontogenesis and of phylogenesis, with
so great certainty point, Haeckel denominates the Chordonium. As
if to put the solution of this important question beyond the possi-
bility of a future doubt, it is now found that a member of this same
group, the Appendicularia, actually preserves its chorda during life,

50 GENESIS OF MAN.

and this creature may therefore be regarded as a living representa-
tive of the true Chordonium.

The Amphioxus forms the zzzth stage in the anthropogenetic
line, and furnishes the first link in the vertebrate chain. It is the
only known representative of the once great subdivision of verte-
brates called by Haeckel the Acranza, or skulless vertebrates.! Of
this wholly unique and extremely interesting creature sufficient
mention has already been made.

The ¢enth stage is that of the Monorhina, or Cyclostoma, which
have for their best-known representative the Petromyzon or lamprey.
These arose out of the Acrania through a simple enlargement of
the anterior extremity of the spinal nerve and the differentiation of
the corresponding part of the chorda dorsals into a rudimentary
cranium. The distinctive circular mouth-orifice Haeckel regards
as a mere adaptive character not present in the original progenitor
of the Crantota.

The transition to the eleventh, the Selachian or primordial fish-
stage, took place through the formation of a pair of nostrils and a
pair of jaws out of the simple, circular mouth-orifice of the Cyclos-
toma. This transformation led to the Amphirhina, a branch of
the Craniota, systematically coordinate with the onorhina, but
embracing all the rest of the vertebrate sub-kingdom. With the
higher fishes (Ganoides and Teleostet) human genealogy is not
immediately concerned, but only with the lowest sub-class, the
Selachu, whose present living representatives are few, and comprise
the sharks, rays, etc., but which formed, in the Devonian age, the
chief population of the waters of the globe, as their singular
heterocercal remains, found in the rocks of that period, abundantly
attest.

The transition from the Selachians was next to the Dipneusta,
which constitute the fwe/fth stage. It was brought about by the
natural adaptation of the organs of the body to a partially terres-
_ trial existence. The swim-bladders were transformed into imper-
fect lungs, the nasal orifices, which in fishes have no communication
with the interior of the mouth, established such a communication, .
and the single auricle of the heart divided into two, thus corre-
spondingly improving the circulation of the blood. The Dipueusta

10 See note 9, page 41.

GENESIS OF MAN. 5

51

therefore employed their gills, which they retained, when in the
water, but breathed through their lungs when on land. They form,
therefore, a very anomalous and interesting transition group, con-
necting the lowest fishes with the lowest amphibians. They were
a very large class in paleolithic time, as their dental remains tes-
- tify, but at present only three genera are known, each with a single
species, viz :—Frotopterus annectens, of the rivers of Africa; Lepi-
dosiven paradoxa, of tropical America; and Ceratodus Forsteri, from
South Australian swamps.

Gegenbaur has demonstrated that the real character of the fins
of fishes is that of many-toed feet. The changes that led from the
fish to the Dipneusta seem not to have affected the number of these
toes, although a certain adaptation of the fins to terrestial locomo-
tion was perceptible. The next important, transformation was to
concern this part of the animal anatomy. The animals nearest
related to the Dipneusta are unquestionably the amphibians, with
which the former are frequently classed; but they differ from them
in the important respect of possessing regular, five-toed feet. But
one conclusion can be drawn from this fact, and this is that among
the many and varied forms of the once great Dipneusta class, there
was one whose locomotive organs had become transformed through
adaptation and natural selection into five-toed feet, and that from
this long extinct five-toed progenitor, the present amphibians have
descended. The human embryo itself, and that of all the higher
vertebrates, pass through an analogous transition.

With frogs, toads, and other higher amphibians, as we are most
familiar with them, the anthropogenetic line has no direct connec-
tion. It constantly hugs the base of the whole group, exhibiting
direct relationships only with the Sozobranchia, which, therefore,
form the ¢hirtecenth, and the Sogura, which form the fourteenth
stage.
The former of these sub-classes comprises the Proteus, the Szren,
and the Szvedon, as among its best-known representatives, while to
the latter belong the Triton and the Salamander. These once
abundant but now comparatively rare creatures have furnished
naturalists with some of the most interesting examples of what
may almost be called the weszble transmutation of species. It is
well known that frogs and toads (Anura), the more highly differ-
entiated amphibians, instead of possessing both lungs and gills

52 GENESIS OF MAN.

during life, as do the Dipneusta, undergo a complete metamor-
phosis after birth, passing from a true fish-form, in the tadpole
state (in which, in addition to the well-known external fish-like
characters, they also possess gills and no lungs and a correspond-
ing piscine circulation) to the familiar batrachian form, in which
their respiration is through lungs only and their circulation through
two auricles. Now, the two sub-classes above named furnish the
most perfect and characteristic transition stages between the larval
and adult stages of the higher amphibians. The Sozobranchia, as
the term implies, preserve their gills through life, but also acquire
lungs, and are therefore strictly amphibious. They live, however,
chiefly in the water, and there perform all the functions of their
existence. The greatest excitement in scientific circles has been
recently called forth by the extraordinary conduct of a member of
this group. The Mexican Axolotl (Szredon pisciforme) was observed
in the Paris Fardin des Plantes, where large numbers of these
creatures were kept, to frequently take to the land, and several
individuals so far habituated themselves to terrestial life that they
actually lost their gills in the manner of the higher amphibians.
Individuals thus behaving were scarcely distinguishable from the
Amblystoma, a genus of the Sozura which acquire lungs.

An equally remarkable phenomenon, but of exactly the opposite
class, was manifested by the Triton, which belongs to the last
named sub-class, and therefore habitually undergoes the metamor-
phosis common to frogs, etc., only without the loss of the tail.
Before it arrives at maturity, the Triton, under ordinary circum-
stances, loses its gills and leads a sub-terrestrial life, breathing
only air. But by placing it in a tank so shaped that it was unable
to get out of the water, it was thus compelled to retain its gills
through life, and even propagated in the water.

All animals above the amphibians are characterized by the pos-
session, during their embryonic stages, of the important organ called
the amnion, which is wanting in all below them, and in the amphib-
ians themselves. The facts of ontogenesis, as well as those of com-
parative anatomy, justify the assumption of the former existence,
probably in the beginning of the Mesozoic age, of a lizard-like
animal whose fossil remains have not yet been discovered, and -
whose affinities with any known living form are not close, but ©
which must have been the first to develop this particular organ,

GENESTS OF MAN; 53

and was thus the progenitor of all that now possess it, and hence
of man himself. This creature, which forms the /i/teenth stage of
man’s genealogy, Haeckel calls the Protamnion. Out of it was
developed primarily the great reptilian class, from which proceeded
later the birds, with neither of which has man any direct connec-
tion. The origin of the mammals, however, must also be sought
in the Protamnion stock, from which this class, too, must have pro-
ceeded,—perhaps simultaneously with the reptilian branch, though
in quite a different direction. The skull of all reptiles and birds
is articulated to the atlas by means of a single condyle, while in
mammals this condyle is double. From this circumstance the
reptiles and birds have been designated by the common term
Monocondylia. \n them, also, the lower jaw is.composed of several
pieces, and movably joined with the skull by a special process,
while in the mammals it consists only of a pair of pieces, and is
immediately connected with the temporal bone. The further dis-
tinction between the scales and feathers of the former and the
hairs of the latter, is likewise an important one. The complete
diaphragm of mammals, dividing the thoracic entirely from the
abdominal viscera, and which is only partial in the J/onocondyha,
is a further very characteristic distinction. Finally, the existence
of mammary glands in the latter, from which the class takes its
name, and which are wanting in all other creatures, not only indi-
cates a very distinct position for the mammals, but combines with
other characters to place them at the head of the animal series.

A very distinct race, which Haeckel styles the Promammaha,
forming the next or szxteenth stage of man’s descent, must have
developed out of the Profamnia, and transmitted all these marked
peculiarities to the entire mammalian class. Man himself possesses
all these special mammalian characteristics, and is therefore a
genuine mammal.

The nearest known living representative of these hypothetical
Promammata are the curious and remarkable Monotremata of
Australia and Tasmania. Of the entire sub-class only three forms
are known, the singular Ovrinthorhynchus paradoxus and the
Echidna, of which there are two species, A. hystrix and £. sefosa.
These animals seem, at first sight, to form an immediate connecting
link between the birds and the mammals, as they possess the beak
of the former with the lacteal glands of the latter. They further

54 GENESIS OF MAN.

agree with the birds in having the anterior extremities of the

clavicles united to the sternum, forming a sort of merrythought.

A still more fundamental point of resemblance to the birds, and

that from which the sub-class takes its name, is the possession of
a common cloaca. the urino-genital duct opening within the body.

The monotremes, however, agree with the mammals in all the

characteristic attributes above enumerated, such as double occipital

condyle, complete diaphragm, etc., while the cloaca, the merry- ~
thought, and other apparently avian characters, may have been

inherited as well from the amphibians as from the birds. The

beak, however, can only be accounted for as having developed

independently from adaptation to conditions of existence similar to

those which evolved the toothless jaws of turtles, from which it is

believed the beak of birds has been derived. The beak of the

Echidna differs from that of the Oruithorhynchus, and exhibits an

approach towards the snout of the ant-eaters. The beaks of
monotremes and of birds must therefore be regarded as simply

analogous, and not as homologous organs.

The Promammalia no doubt differed in many respects from the
Monotremata, and Haeckel is inclined to believe that they pos-
sessed regular teeth, which the latter lost through adaptive modifi-
cation. At least, the earliest fossil remains that paleontologists
have been able to refer with certainty to the mammals, and which
occur in the triassic formation, consist of teeth only. From a few
small molar teeth found in Germany, and also in England, Mcro-
lestes antiqguus has been constructed; and from similar dental
remains found in this country, Dromatherium sylvestre has been
described.

Although the Monotremata differ from the Monocondyha (rep-
tiles and birds) in so many important respects in which they agree
with the higher mammals, they, nevertheless, also present many
points of difference with these latter. In addition to those already ~
mentioned (cloaca, united clavicule, etc.), the absence in these
animals of any teats upon the mammary glands is very peculiar
and anomalous. In consequence of this omission, the only way
in which the young are able to obtain their nourishment, is by a
process of licking against the porous breast of the mother; and
Haeckel, therefore, proposes as a synonym for the ordinary name
of the sub-class, that of Azzasta,—or mammals without teats.

GENESIS OF MAN. ss

Again, the a//antois is never transformed into a placenta, the corpus
callosum is not developed, and there exists a pair of rudimentary
marsupial bones. This last character affords almost conclusive
proof of the descent of the marsupials from the monotremes.

The Marsupialia must therefore be regarded as the next group
of animals in the regular line of descent which terminates in man,
and as forming the seventeenth stage in the development of the
-human race. Here the cloaca is divided by a horizontal partition
into two distinct orifices, both opening externally; nipples are
formed on the mammac,to which the young attach themselves,
and the clavicles are distinct from the sternum. In these respects,
the marsupials agree with all the higher mammals. The distin-
guishing character in which they differ from them, and that from
which the name of the sub-class has been taken, is the existence
of a remarkable pouch or sack (marsupium) on the under side of
the female, in which the young are placed at a very early period,
and there retained until they are able to take care of themselves.
This pouch has been aptly likened to a second or supplementary
uterus, and the marsupials have accordingly been called by some
Didelphia. Our well-known opossum (Didelphys opossum) is our
only North American representative; but in Australia, this group
of animals constitutes the greater part of the mammalian fauna.

The absence of a placenta is the only other important particular
in which the marsupials differ from the higher mammals. Indeed,
the marsupium seems to constitute a sort of substitute for a pla-
centa, and the want of the latter may be regarded as the physio-
logical cause of the development of the former. The monotremes,
however, are without either, and those who know would do well to
explain how these animals are able ta dispense with them both.

The so-called true Mammalia all possess a fully developed pla-
centa, and are therefore distinguished from the two groups last
mentioned as forming a third sub-class, the Flacentalia. This
organ is of great importance in the classification of the higher
mammals, its mode of attachment furnishing excellent and reliable
general characters. In some, for example, the placenta is decidu-
ous from the inner wall of the uterus, while in others it is not, and
on this distinction is based the primary division of the whole sub-
class into the Deciduata and the /udectdua. ‘The latter are the
least perfectly organized, and comprise the Edentata, the Cetacea,

56 GENESIS OF MAN.

and the Ungulata. In man the placenta is deciduous, and he can
therefore have descended from none of these.

The Deciduata again fall into two divisions according as the
embryo is attached by the placenta to the uterus upon a single
small area or disk, or by a band or girdle extending entirely
around it. The former are called Dzscoplacentalia, the latter Zono-
placentalia. The Zonoplacentalia embrace the Carnaria ( Carniwora

and Pinnipedia) and the Chelophora, to which the elephant belongs. -

The Discoplacentalia comprise the rodents, the /zsectivora (moles,
etc.), the Chzroptera (bats), the lemurs (Prosimiac), and the apes
(Szmzae). To this last legion, also, belongs man, who differs in
this respect not at all from the mouse, mole, bat, lemur, or ape.
Now it is a remarkable fact that in one order of the marsupials,
the Pedimana, embracing the two families Chzronectida and Didel-
phyida, to the last of which our opossum belongs, the hind feet are
modified, in a peculiar way, into organs for grasping, resembling
hands. ‘This group can therefore only be regarded as exhibiting
the earliest marks of that important course of transformation
which culminated in the apes and in man. The course of develop-
ment was from this group of marsupials directly to one within the
Deciduata. Weaving all other animals wholly out of its course, the
line of descent of man passes immediately from the J/arsupialia to
the Prosimiae or lemur group, an order which Haeckel takes out
of Blumenbach’s Quadrumana, because it is so much farther sepa-
rated from the other apes than any of these are from one another.
They are ape-like creatures, but shade off in a very interesting
way into nearly all the remaining orders of the Descoplacentaha.
The Chiromys Madagascariensis forms the transition to the rodents;
the Galeopithecus of the Sunda Islands, to the bats; the Macrotarsz,
to the insectivora; and the Srachytarsi, particularly the Lori
(Stenops), to the true apes. They also exhibit close affinities to
the Sloths (Sradipoda), which have been regarded as an order of
the Edentata in the Indecidua; but recent investigations have
proved that they have a deciduous placenta, and therefore it must
be at this point that the Deciduata and the Indecidua join. The
lemurs are harmlessand melancholy nocturnal animals of a graceful
form, and are chiefly confined to the islands south of Asia and east
of Africa, and particularly to Madagascar. Their frequency on
the islands of the Indian Ocean led the English naturalist Sclater

GENESIS OF MAN. 57

to name this once continental, but now mostly submerged region,
Lemuria, a circumstance to which Haeckel has given special promi-
nence, by pointing out the many facts which conspire to justify us
in the conjecture that here may have existed the true “cradle of
the human race.” The lemurs form the ezghteenth stage in the
anthropogenetic line.

From the lemurs to the true apes, the transition is comparatively
easy. They evidently developed out of the Brachytarsi, the Ste-
nops forming the nearest approach to a connecting link.

Linnzus, with almost prophetic ken, notwithstanding his dual-
istic proclivites, classed man with the apes, lemurs, and bats, in
his celebrated order, Primates. Blumenbach fancied he saw in the
human foot a pretext for rescuing man from this association, and
accordingly erected for him a separate order, which he called
Bimana (two-handed), distinguishing the apes, etc., as Quadru-
mana (four-handed). This classification was adopted by Cuvier,
and is the one which has generally prevailed among naturalists,
down to Huxley and Haeckel. Huxley, however, gave the whole
subject a complete re-investigation, and arrived at the conclusion
that Blumenbach’s order 4zmzana cannot be maintained on anato-
mical grounds. He shows, in the most convincing manner, that
the distinctions alleged to exist between the posterior hands of
apes and the feet of man are apparent only, that they were based
on physiological and not on morphological considerations. The
apes are just as good bimana as men are, and men are just as
good quadrumana as the apes. In neither are the posterior limbs
in all respects homologous to the anterior. The tarsal bones are
differently arranged from the carpal bones, and there are three
distinct muscles serving to move the foot that are wholly wanting
in the hand. But all this is as true of the apesas of man. The
limited opposability of the great toe in man is only a functional
distinction. The muscles of opposability are all present; they are
merely atrophied by disuse and adaptation to altered conditions.
Traces of this power are found in many savages, who hold on with
their toes to the branches of trees in the forests where they live,
and otherwise employ this posterior thumb ina variety of ways
which Europeans cannot imitate. There are, moreover, many
instances on record of men acquiring extraordinary dexterity in
the use of their toes. Every one in this country has seen the exhi-

58 GENESIS OF MAN.

bitions of the armless man, who travelled through our towns and
displayed marvellous feats performed with his toes. Again, infants
make far more use of their great toes than adults do. Watch a
new-born babe as it lies in its cradle and amuses itself with exer-
cise of its muscular activities; compare the movements of its
hands with those of its feet, and you cannot but be struck with the
comparative indifference with which it manages both. The human
foot, whose careful study has been said to constitute a sure cure
for atheism, and whose wonderful adaptation to the purpose to
which it is applied has been regarded as an unanswerable argument
for the doctrine of design, can therefore be nothing more than a
natural result of the modification of the posterior hand of the ape,
in simple obedience to the mechanical law of adaptation to changed ©
conditions, while in it are found all the visible elements of that
ancestral organ which the equally monistic law of heredity has
transmitted from our simian progenitors. Huxley, therefore, re-
stores the Linnean order Primates, removing only the Chiroptera.
Haeckel, however, would adhere to his order Prosimiae, the lemurs,
for the reasons above stated.

The true apes are primarily divided into two great groups, which
are as distinct geographically as they are anatomically. These are
the Catarrhinae or Old World apes, and the Platyrrhinae, or New
World monkeys. They differ chiefly in two important respects.
The Platyrriinae have a flat and broad nose, like other animals.
The nostrils open outwardly, and are separated by a broad interval.
They have, also, thirty-six teeth, eighteen in each jaw. In both
these respects they differ from man. The Catarrhinae, on the
other hand, have a somewhat projecting, laterally compressed, and
often arched or aquiline nose, with the nostrils close together and
opening downwards. They have only thirty-two teeth, or sixteen
in each jaw. In both these respects they agree with man. The
clear-cut, much projecting, and elegantly formed nose of the Nose-
ape (Semmnopithecus nasicus) would adorn the face of any European
nobleman, while the countenance, taken in its exsemzble, of Cerco-
pithecus petaurista would be sure to call to any one’s mind some
not very bad-looking person of his own acquaintance. And yet
these handsome apes are endowed with long tails. Not only is
the number of the teeth of the Catarrhinae the same as in man,
but they are distributed in precisely the same manner, namely :—

GENESIS OF MAN. | 59

four incisors, two canine or eye-teeth, and ten molars or grinders,
in each jaw.

The Catarrhinae are further divided into two groups of tail-
bearing and tailless apes. The tail-bearing apes have most proba-
bly been developed directly from the lemurs, and therefore con-
stitute the meteenth stage in the descent of man. Our ancient
forefathers in this group were perhaps similar to the now living
Semnopithecus, from which the tailless apes, forming the twentieth
stage, were differentiated chiefly by the loss of their tail. These
latter bear the greatest resemblance to man, and are called anthro-
poid apes, constituting the family Anthropoides. The family con-
sists, as far as known, of but four genera, Hylobates, the Gibbon
of southern Asia; Satyrus, the Orang of Borneo and the Sunda
Islands; Anxgeco, the Chimpanzee of southern and western Africa,
and the Gorilla, first discovered by the missionary Wilson, in 1847,
on the Gaboon River, western Africa, and afterwards by Du
Chaillu. The Gorilla is the largest of known apes, and exceeds
the human stature.

To none of these four anthropoid apes, however, can we point
as being in all respects the nearest toman. The Gibbon resembles
man most in the form of the thorax, the Orang in the development
of the brain, the Chimpanzee in the formation of the skull, and
the Gorilla in the differentiation of hand and foot, and also in the
relative length of the arms. It is therefore evident that man can-
_ not have descended directly from any known living ape. His real
progenitor must, in a greater or less degree, have combined all
these characters, and has no doubt been long extinct. It is from
paleontology that we alone hope for aid in the discovery of this
“missing link.” The fossil remains of this extinct genus (Pithecan-
thropus) may be looked for with some corifidence in the still little
known region of south-eastern Asia, the Malay Archipelago, and
throughout central and western Africa.

The comparative anatomy and osteology of these four genera
of anthropoid apes have been exhaustively studied by Carl Vogt,
Huxley, and others. The final conclusion to which Huxley comes,
and which he expresses in the most unqualified and emphatic
manner, is that no matter what system of organs we take, a com-
parison of the modifications in the Catarrhine series leads to one
and the same result: that the anatomical differences that distin-

60 GENESIS OF MAN.

guish man from the Orang, Gorilla or Chimpanzee, are not as great
as those which distinguish these latter from the lower Catarrhinae
(Cynocephalus, Makako, Cercopithecus). Therefore, as Haeckel
remarks, it is incorrect to say that man has descended from the
apes; he is himself an ape, and belongs as strictly to the Catarrhine
group as the Gorilla or the Orang-outang! He therefore estab-
lishes another family within that group, together with the Avzzhro-
poides, which he calls the 4rectt or Anthropi. This family he
divides into two genera, the first embracing the now extinct ances-
tor of the human race, the Pithecanthropus or ape-man, which
therefore forms the /wenty-first genealogical stage, and the second
being the genus Homo, or man as we find him, forming the zwezty-
second and last stage in his development from the moner.

Three anatomical distinctions of any importance are all that
exist to separate the two families Anthropoides and Anthropi. One
is the more erect posture of the latter—a difference of degree,
however, which varies both with the apes and with men. The
second is the higher brain development of the latter, which is also
only a quantitative distinction. The third and only distinction
which can be called qualitative, is the differentiation in the An-
thropi of the larynx into an organ of speech. And not even this
much can now be fairly said, since it is found that the larynx of
monkeys exhibits a much higher state of development than that
of other animals.” Haeckel, however, regards Pithecanthropus as
a speechless man, having the erect posture and differentiated brain,
but who had not yet acquired the power of articulate language, or
the necessary organs for its utterance. For this reason he offers
also a synonym for his name Pithecanthropus, the equally appro-
priate one, A/alus, the speechless. This, however, is only theory.
In point of fact, the ereét posture, size and quality of brain, forma-
tion of vocal cords, and the origin of articulate speech, must have
all advanced pari passu, mutually promoting one another, and
developing by insensible degrees, according to the universal
method of all nature.

To the various races of men as recognized by ethnologists,
Haeckel, in harmony with his general system, gives the rank of
species of the genus Homo. All definitions of the term species

10 Emile Blanchard, «‘ Voice in Man and Animals,” in Popular Science Monthly,
September, 1876, page 519.

GENESIS OF MAN. 61

having failed to unite upon any absolutely constant character as a
condition to its application, the use of it here is justifiable, not-
withstanding the ease with which the human races hybridize, and
no matter what theory may be preferred of their origin or rela-
tionships. Of these species he makes out twelve, and advances an
interesting theory of their origin and geographical distribution
over the globe; but upon this new field we can here follow him
no farther.

In casting a retrospective glance over the vast subject thus
hastily passed in review, there are a few salient points which will
have most probably, in an especial manner, struck the mind of the
reader.

One of these is likely to be the great brevity of the anthropo-
genetic line,—considering the variety and multiplicity of living
forms found on the globe. We perceive that of the seven sub-
kingdoms of animals now recognized, only three are touched by
it, viz:—the Protozoa, Worms, and Vertebrates. The zoophytes,
echinoderms, anthropods, and mollusks all branch off either below
or at the worm stage, and the transition from the Zumcata,a
worm-form, is direct to the vertebrata. This, when adequately
appreciated, is an astonishing fact, and one which would never
have been conjectured but for positive anatomical evidences.
Those who believed in a law of development were looking vainly
for proof of the derivation of the different types one out of anoth-
er, and discussing which should be considered lowest, the articu-
lates or the mollusks. They expected to find proof of a series
with the radiates at the bottom and the vertebrates at the top.
The truth, as it has at last dawned upon us, dispenses with all such
speculations.

Equally surprising is the shortness and directness of the transi-
tion from the lowest to the highest vertebrates, from the Amphi-
oxus to the Ape. All the vague surmises of some extensive
course of descent and lineal relationship among the numerous
classes and orders of vertebrates are now also brought to an end.
The higher fishes and higher amphibians, the reptiles and the
birds, are all left to pursue special routes of their own; and a brief
series of easy and rapid transitions through the lowest fish-form,
the Selachia, and the lowest amphibian-forms, the Sozobranchia
and Sozura, brings us at once to the lowest mammalian stage.

62 GENESIS OF MAN.

But perhaps the most surprising part of this whole course is its
one great stride through the entire mammalian class, from the
marsupial to the lemur. All vain expectations of finding some
thread of relationship that should lead through the labyrinth of
varied mammalian orders, and connect us with the horse, the dog,
the elephant, etc., are thus happily set at rest, and we are permitted
only to claim such consanguineal relationship with the opossum,
the lemur and the ape.

In fact, instead of a long concatenated “chaine animale,” as La-
marck supposes, the animal kingdom presents rather a tree, spread-
ing from very near the base with almost a whorl of unequal
branches or subordinate trunks, each of which is again variously
branched, giving the whole the form of an inverted cone or pyra-
mid. At the upper extremity of each of these branches, which
have come a long way independently of each other, is found one
of the great groups or types of now living creatures, man occupy-
ing the highest summit of the vertebrate branch.

Contemplating now the great number of branches that arise at
different points, some of which are short and apparently stunted,
while others push upward with different degrees of vigor, only
one or two reaching truly lofty and commanding positions, the
thought forcibly strikes us that this picture reveals the universal
tendency of Nature to develop organic forms. We realize that
this vital force or mzsus is constantly pressing at every point, but
that as the conditions of life are limited, success is possible only at
a few points; that in consequence of obstacles of many kinds, not
the least of which are offered by organic conditions themselves
that have pre-occupied the field, the degree of success at these
points varies widely, and produces all grades of vigor, size, length,
and ramification among the branches. The highest and most
thrifty branches mark the line of absolutely least resistance; the
shorter and less vigorous ones indicate lines offering varied degrees
of resistance; while the stunted, dwarfed, and retrograde branches
show lines of resistance so great that the vital force barely over-
comes it. Finally, all points from which no buds or branches
arise teach us over how large a proportion of nature the resisting
agencies wholly overbalance the organic tendencies, and no life
can originate.

Another thought to which the attentive contemplation of this

GENESIS OF MAN. 63

theme gives rise, is the greater antecedent probability of like
organs, occurring in different animals, being homologous, than of
their being analogous. The conditions in which life finds itself
placed are so infinitely variable, that the chances are almost infinity
to one against the development of the same organ independently
at two different times and places. Where the same organ is unex-
pectedly found in two animals which had not been supposed to be
at all related, it affords the strongest evidence that they are either
immediately connected by blood, or at least that they have both
descended from a common ancestor that possessed that organ.
Hence the irresistible force of the testimony afforded by the so-
called “rudimentary organs,’ which none but those who realize
this important law can properly appreciate. That analogues do
sometimes occur, in obedience to the law of adaptation, cannot,
however, be denied; but they usually betray their origin by being
formed on an essentially different principle, though in such a man-
ner as to accomplish the same purpose. The wings of birds, bats,
and insects are such cases of analogy, in each of which the morpho-
logical differentiation is wholly different, while the physiological
function is the same. The beak of the Ornithorhynchus is perhaps
aS near an approach as we have to a true morphological analogue,
the descent of that animal from the birds being overruled by a
preponderance of evidence against it.

It is this principle, too, which conclusively negatives the pre-
sumption which some have advanced, that the aborigines of
America may have descended from the New World monkeys.
Catarrhine man could never have sprung from a Platyrrhine ape.

It is, moreover, this same biological law which justifies Haeckel
in the assumption of so many hypothetical and long-extinct ances-
tral forms, although no warrant for them is afforded by paleonto-
logy. The Gastraea, the Chordonium, the Protamnion, the Pro-
mammalia, and the Pithecanthropus are all creatures, not of his
imagination, but of stern logic, based on a profound familiarity
with all the facts and principles that bear upon the problem. The
common origin and blood relationship of all creatures that possess
a spinal column, of all that are endowed with five-toed feet, of all
that develop an amnion, of all that have the double occipital con-
dyle, of all that suckle their young, of all having the fore and hind
feet differentiated into hands, of all that have the catarrhine nose

t10 t

account for these facts. The i of ©
many independent morphological analogues,
tion to identical conditions, are but as one to infinity.
‘ . Either the dualistic conception of teleological de
cle, must be admitted, or else there is no alternative {
planation.