FOOTNOTES:

This is certainly, for the time it was written, an original, comprehensive, and bold attempt at explaining in a tentative way, or at least suggesting, the probable origin of man from some arboreal creature allied to the apes. It is as regards the actual evolutional steps supposed to have been taken by the simian ancestors of man, a more detailed and comprehensive hypothesis than that offered by Darwin in hisDescent of Man,[197]which Lamarck has anticipated. Darwin does not refer to this theory of Lamarck, and seems to have entirely overlooked it, as have others since his time. The theory of the change from an arboreal life and climbing posture to an erect one, and the transformation of the hinder pair of hands into the feet of the erect human animal, remind us of the very probable hypothesis of Mr. Herbert Spencer, as to the modification of the quadrumanous posterior pair of hands to form the plantigrade feet of man.

FOOTNOTES:[195]Author’s italics.[196]“How much this unclean beast resembles man!”—Ennius.“Indeed, besides other resemblances the monkey has mammæ, a clitoris, nymphs, uterus, uvula, eye-lobes, nails, as in the human species; it also lacks a suspensory ligament of the neck. Is it not astonishing that man, endowed with wisdom, differs so little from such a disgusting animal!”—Linnæus.[197]Vol. i., chapter iv., pp. 135–151; ii., p. 372.

[195]Author’s italics.

[196]“How much this unclean beast resembles man!”—Ennius.“Indeed, besides other resemblances the monkey has mammæ, a clitoris, nymphs, uterus, uvula, eye-lobes, nails, as in the human species; it also lacks a suspensory ligament of the neck. Is it not astonishing that man, endowed with wisdom, differs so little from such a disgusting animal!”—Linnæus.

[196]“How much this unclean beast resembles man!”—Ennius.

“Indeed, besides other resemblances the monkey has mammæ, a clitoris, nymphs, uterus, uvula, eye-lobes, nails, as in the human species; it also lacks a suspensory ligament of the neck. Is it not astonishing that man, endowed with wisdom, differs so little from such a disgusting animal!”—Linnæus.

[197]Vol. i., chapter iv., pp. 135–151; ii., p. 372.

Onewho has read the writings of the great French naturalist, who may be regarded as the founder of evolution, will readily realize that Lamarck’s mind was essentially philosophic, comprehensive, and synthetic. He looked upon every problem in a large way. His breadth of view, his moral and intellectual strength, his equably developed nature, generous in its sympathies and aspiring in its tendencies, naturally led him to take a conservative position as to the relations between science and religion. He should, as may be inferred from his frequent references to the Author of nature, be regarded as a deist.

When a very young man, he was for a time a friend of the erratic and gifted Rousseau, and was afterwards not unknown to Condorcet, the secretary of the French Academy of Sciences, so liberal in his views and so bitter an enemy of the Church; and though constantly in contact with the radical views and burning questions of that day, Lamarck throughout his life preserved his philosophic calm, and maintained his lofty tone and firm temper. We find no trace in his writings of sentiments other than themost elevated and inspiring, and we know that in character he was pure and sweet, self-sacrificing, self-denying, and free from self-assertion.

The quotations from hisPhilosophie zoologique, published in 1809, given below, will show what were the results of his meditations on the relations between science and religion. Had his way of looking at this subject prevailed, how much misunderstanding and ill-feeling between theologians and savants would have been avoided! Had his spirit and breadth of view animated both parties, there would not have been the constant and needless opposition on the part of the Church to the grand results of scientific discovery and philosophy, or too hasty dogmatism and scepticism on the part of some scientists.

In Lamarck, at the opening of the past century, we behold the spectacle of a man devoting over fifty years of his life to scientific research in biology, and insisting on the doctrine of spontaneous generation; of the immense length of geological time, so opposed to the views held by the Church; the evolution of plants and animals from a single germ, and even the origin of man from the apes, yet as earnestly claiming that nature has its Author who in the beginning established the order of things, giving the initial impulse to the laws of the universe.

As Duval says, after quoting the passage given below: “Deux faits son à noter dans ce passage: d’une part, les termes dignes et conciliants dans lesquels Lamarck établit la part de la science et de la religion; cela vaut, mieux, même en tenant comptedes différences d’epoques, que les abjurations de Buffon.”[198]

The passage quoted by M. Duval is the following one:

“Surely nothing exists except by the will of the Sublime Author of all things. But can we not assign him laws in the execution of his will, and determine the method which he has followed in this respect? Has not his infinite power enabled him to create an order of things which has successively given existence to all that we see, as well as to that which exists and that of which we have no knowledge? As regards the decrees of this infinite wisdom, I have confined myself to the limits of a simple observer of nature.”[199]

In other places we find the following expressions:

“There is then, for the animals as for the plants, an order which belongs to nature, and which results, as also the objects which this order makes exist, from the power which it has received from theSupreme Authorof all things. She is herself only the general and unchangeable order that this Sublime Author has created throughout, and only the totality of the general and special laws to which this order is subject. By these means, whose use it continues without change, it has given and will perpetually give existence to its productions; it varies and renews them unceasingly, and thus everywhere preserves the whole order which is the result of it.”[200]

“To regard nature as eternal, and consequentlyas having existed from all time, is to me an abstract idea, baseless, limitless, improbable, and not satisfactory to my reason. Being unable to know anything positive in this respect, and having no means of reasoning on this subject, I much prefer to think thatall natureis only a result: hence, I suppose, and I am glad to admit it, a first cause, in a word, a supreme power which has given existence to nature, and which has made it in all respects what it is.”[201]

“Nature, that immense totality of different beings and bodies, in every part of which exists an eternal circle of movements and changes regulated by law; totality alone unchangeable, so long as it pleases itsSublime Authorto cause its existence, should be regarded as a whole constituted by its parts, for a purpose which its Author alone knows, and not exclusively for any one of them.“Each part is necessarily obliged to change, and to cease to be one in order to constitute another, with interests opposed to those of all; and if it has the power of reasoning it finds this whole imperfect. In reality, however, this whole is perfect and completely fulfils the end for which it was designed.”[202]

“Each part is necessarily obliged to change, and to cease to be one in order to constitute another, with interests opposed to those of all; and if it has the power of reasoning it finds this whole imperfect. In reality, however, this whole is perfect and completely fulfils the end for which it was designed.”[202]

Lamarck’s work on general philosophy[203]was written near the end of his life, in 1820. He begins his “Discours préliminaire” by referring to the sudden loss of his eyesight, his work on the invertebrate animals being thereby interrupted. The book was, he says, “rapidly” dictated to his daughter, and the ease with which he dictated was due, he says, to his long-continued habit of meditating on the facts he had observed.

In the “Principes primordiaux” he considers man as the only being who has the power of observing nature, and the only one who has perceived the necessity of recognizing a superior and only cause, creator of the order of the wonders of the world of life. By this he is led to raise his thoughts to theSupreme Authorof all that exists.

“In the creation of his works, and especially those we can observe, this omnipotent Being has undoubtedly been the ruling power in pursuing the method which has pleased him, namely, his will has been:“Either to create instantaneously and separately every particular living being observed by us, to personally care for and watch over them in all their changes, their movements, or their actions, to unremittingly care for each one separately, and by the exercise of his supreme will to regulate all their life;“Or to reduce his creations to a small number, and among these, to institute an order of things general and continuous, pervaded by ceaseless activity (mouvement), especially subject to laws by means of which all the organisms of whatever nature, all the changes they undergo, all the peculiarities they present, and all the phenomena that many of them exhibit, may be produced.“In regard to these two modes of execution, if observation taught us nothing we could not form any opinion which would be well grounded. But it is not so; we distinctly see that there exists an order of things truly created (véritablement créé), as unchangeable as its author allows, acting on matter alone, and which possesses the power of producing all visible beings, of executing all the changes, all the modifications, even the extinctions, so also the renewals or recreations that we observe among them. It is to this order of things that we have given thename ofnature. The Supreme Author of all that exists is, then, the immediate creator of matter as also of nature, but he is only indirectly the creator of what nature can produce.“The end that God has proposed to himself in creating matter, which forms the basis of all bodies, and nature, which divides (divise) this matter, forms the bodies, makes them vary, modifies them, changes them, and renews them in different ways, can be easily known to us; for the Supreme Being cannot meet with any obstacle to his will in the execution of his works; the general results of these works are necessarily the object he had in view. Thus this end could be no other than the existence of nature, of which matter alone forms the sphere, and should not be that causing the creation of any special being.“Do we find in the two objects created,i.e.,matterandnature, the source of the good and evil which have almost always been thought to exist in the events of this world? To this question I shall answer that good and evil are only relative to particular objects, that they never affect by their temporary existence the general result expected (prévu), and that for the end which the Creator designed, there is in reality neither good nor evil, because everything in nature perfectly fulfils its object.“Has God limited his creations to the existence of only matter and nature? This question is vain, and should remain without an answer on our part; because, being reduced to knowing anything only through observation, and to bodies alone, also to what concerns them, these being for us the only observable objects, it would be rash to speak affirmatively or negatively on this subject.“What is a spiritual being? It is what, with the aid of the imagination, one would naturally suppose (l’on vaudra supposer). Indeed, it is only by means of opposing that which is material that we can formthe idea of spirit; but as this hypothetical being is not in the category of objects which it is possible for us to observe, we do not know how to take cognizance of it. The idea that we have of it is absolutely without base.“We only know physical objects and only objects relative to these beings (êtres): such is the condition of our nature. If our thoughts, our reasonings, our principles have been considered as metaphysical objects, these objects, then, are not beings (êtres). They are only relations or consequences of relations (rapports), or only results of observed laws.“We know that relations are distinguished as general and special. Among these last are regarded those of nature, form, dimension, solidity, size, quantity, resemblance, and difference; and if we add to these objects the being observed and the consideration of known laws, as also that of conventional objects, we shall have all the materials on which our thoughts are based.“Thus being able to observe only the phenomena of nature, as well as the laws which regulate these phenomena, also the products of these last, in a word, only bodies (corps) and what concerns them, all that which immediately proceeds from supreme power is incomprehensible to us, as it itself [i.e., supreme power] is to our minds. To create, or to make anything out of nothing, this is an idea we cannot conceive of, for the reason that in all that we can know, we do not find any model which represents it.Godalone, then, can create, while nature can only produce. We must suppose that, in his creations, the Divinity is not restricted to the use of any time, while, on the other hand, nature can effect nothing without the aid of long periods of time.”

“Either to create instantaneously and separately every particular living being observed by us, to personally care for and watch over them in all their changes, their movements, or their actions, to unremittingly care for each one separately, and by the exercise of his supreme will to regulate all their life;

“Or to reduce his creations to a small number, and among these, to institute an order of things general and continuous, pervaded by ceaseless activity (mouvement), especially subject to laws by means of which all the organisms of whatever nature, all the changes they undergo, all the peculiarities they present, and all the phenomena that many of them exhibit, may be produced.

“In regard to these two modes of execution, if observation taught us nothing we could not form any opinion which would be well grounded. But it is not so; we distinctly see that there exists an order of things truly created (véritablement créé), as unchangeable as its author allows, acting on matter alone, and which possesses the power of producing all visible beings, of executing all the changes, all the modifications, even the extinctions, so also the renewals or recreations that we observe among them. It is to this order of things that we have given thename ofnature. The Supreme Author of all that exists is, then, the immediate creator of matter as also of nature, but he is only indirectly the creator of what nature can produce.

“The end that God has proposed to himself in creating matter, which forms the basis of all bodies, and nature, which divides (divise) this matter, forms the bodies, makes them vary, modifies them, changes them, and renews them in different ways, can be easily known to us; for the Supreme Being cannot meet with any obstacle to his will in the execution of his works; the general results of these works are necessarily the object he had in view. Thus this end could be no other than the existence of nature, of which matter alone forms the sphere, and should not be that causing the creation of any special being.

“Do we find in the two objects created,i.e.,matterandnature, the source of the good and evil which have almost always been thought to exist in the events of this world? To this question I shall answer that good and evil are only relative to particular objects, that they never affect by their temporary existence the general result expected (prévu), and that for the end which the Creator designed, there is in reality neither good nor evil, because everything in nature perfectly fulfils its object.

“Has God limited his creations to the existence of only matter and nature? This question is vain, and should remain without an answer on our part; because, being reduced to knowing anything only through observation, and to bodies alone, also to what concerns them, these being for us the only observable objects, it would be rash to speak affirmatively or negatively on this subject.

“What is a spiritual being? It is what, with the aid of the imagination, one would naturally suppose (l’on vaudra supposer). Indeed, it is only by means of opposing that which is material that we can formthe idea of spirit; but as this hypothetical being is not in the category of objects which it is possible for us to observe, we do not know how to take cognizance of it. The idea that we have of it is absolutely without base.

“We only know physical objects and only objects relative to these beings (êtres): such is the condition of our nature. If our thoughts, our reasonings, our principles have been considered as metaphysical objects, these objects, then, are not beings (êtres). They are only relations or consequences of relations (rapports), or only results of observed laws.

“We know that relations are distinguished as general and special. Among these last are regarded those of nature, form, dimension, solidity, size, quantity, resemblance, and difference; and if we add to these objects the being observed and the consideration of known laws, as also that of conventional objects, we shall have all the materials on which our thoughts are based.

“Thus being able to observe only the phenomena of nature, as well as the laws which regulate these phenomena, also the products of these last, in a word, only bodies (corps) and what concerns them, all that which immediately proceeds from supreme power is incomprehensible to us, as it itself [i.e., supreme power] is to our minds. To create, or to make anything out of nothing, this is an idea we cannot conceive of, for the reason that in all that we can know, we do not find any model which represents it.Godalone, then, can create, while nature can only produce. We must suppose that, in his creations, the Divinity is not restricted to the use of any time, while, on the other hand, nature can effect nothing without the aid of long periods of time.”

Without translating more of this remarkable book, which is very rare, much less known than thePhilosophie zoologique, the spirit of the remainder may be imagined from the foregoing extracts.

The author refers to the numerous evils resulting from ignorance, false knowledge, lack of judgment, abuse of power, demonstrating the necessity of our confining ourselves within the circle of the objects presented by nature, and never to go beyond them if we do not wish to fall into error, because the profound study of nature and of the organization of man alone, and the exact observation of facts alone, will reveal to us “the truths most important for us to know,” in order to avoid the vexations, the perfidies, the injustices, and the oppressions of all sorts, and “incalculable disorders” which arise in the social body. In this way only shall we discover and acquire the means of obtaining the enjoyment of the advantages which we have a right to expect from our state of civilization. The author endeavors to state what science can and should render to society. He dwells on the sources from which man has drawn the knowledge which he possesses, and from which he can obtain many others—sources the totality of which constitutes for him the field of realities.

Lamarck also in this work has built up a system for moral philosophy.

Self-love, he says, perfectly regulated, gives rise:

1. To moral force which characterizes the laborious man, so that the length and difficulties of a useful work do not repel him.

2. To the courage of him who, knowing the danger, exposes himself when he sees that this would be useful.

3. To love of wisdom.

Wisdom, according to Lamarck, consists in the observance of a certain number of rules or virtues. These we cite in a slightly abridged form.

Love of truth in all things; the need of improving one’s mind; moderation in desires; decorum in all actions; a wise reserve in unessential wants; indulgence, toleration, humanity, good will towards all men; love of the public good and of all that is necessary to our fellows; contempt for weakness; a kind of severity towards one’s self which preserves us from that multitude of artificial wants enslaving those who give up to them; resignation and, if possible, moral impassibility in suffering reverses, injustices, oppression, and losses; respect for order, for public institutions, civil authorities, laws, morality, and religion.

The practice of these maxims and virtues, says Lamarck, characterizes true philosophy.

And it may be added that no one practised these virtues more than Lamarck. Like Cuvier’s, his life was blameless, and though he lived a most retired life, and was not called upon to fill any public station other than his chair of zoölogy at the Jardin des Plantes, we may feel sure that he had the qualities of courage, independence, and patriotism which would have rendered such a career most useful to his country.

As Bourguin eloquently asserts: “Lamarck was the brave man who never deserted a dangerous post, the laborious man who never hesitated to meet any difficulty, the investigating spirit, firm in hisconvictions, tolerant of the opinions of others, the simple man, moderate in all things, the enemy of weakness, devoted to the public good, imperturbable under the attaints of fortune, of suffering, and of unjust and passionate attacks.”

FOOTNOTES:[198]Mathias Duval: “Le transformiste français Lamarck,”Bulletin de la Société d’Anthropologie de Paris, xii., 1889, p. 345.[199]Philosophie zoologique, p. 56.[200]Loc. cit., i., p. 113.[201]Loc. cit., i., p. 361.[202]Loc. cit., ii., p. 465.[203]Système analytique des Connaissances de l’Homme, etc.

[198]Mathias Duval: “Le transformiste français Lamarck,”Bulletin de la Société d’Anthropologie de Paris, xii., 1889, p. 345.

[199]Philosophie zoologique, p. 56.

[200]Loc. cit., i., p. 113.

[201]Loc. cit., i., p. 361.

[202]Loc. cit., ii., p. 465.

[203]Système analytique des Connaissances de l’Homme, etc.

Sincethe appearance of Darwin’sOrigin of Species, and after the great naturalist had converted the world to a belief in the general doctrine of evolution, there has arisen in the minds of many working naturalists a conviction that natural selection, or Darwinism as such, is only one of other evolutionary factors; while there are some who entirely reject the selective principle. Darwin, moreover, assumed a tendency to fortuitous variation, and did not attempt to explain its cause. Fully persuaded that he had discovered the most efficient and practically sole cause of the origin of species, he carried the doctrine to its extreme limits, and after over twenty years of observation and experiment along this single line, pushing entirely aside the Erasmus-Darwin and Lamarckian factors of change of environment, though occasionally acknowledging the value of use and disuse, he triumphantly broke over all opposition, and lived to see his doctrine generally accepted. He had besides the support of some of the strongest men in science: Wallace in a twin paper advocated the same views; Spencer, Lyell, Huxley, Hooker, Haeckel, Bates, Semper, Wyman, Gray, Leidy, and otherrepresentative men more or less endorsed Darwin’s views, or at least some form of evolution, and owing largely to their efforts in scientific circles and in the popular press, the doctrine of descent rapidly permeated every avenue of thought and became generally accepted.

Meanwhile, the general doctrine of evolution thus proved, and the “survival of the fittest” an accomplished fact, the next step was to ascertain “how,” as Cope asked, “the fittest originated?” It was felt by some that natural selection alone was not adequate to explain the first steps in the origin of genera, families, orders, classes, and branches or phyla. It was perceived by some that natural selection by itself was not avera causa, an efficient agent, but was passive, and rather expressed the results of the operations of a series of factors. The transforming should naturally precede the action of the selective agencies.

We were, then, in our quest for the factors of organic evolution, obliged to fall back on the action of the physico-chemical forces such as light, or its absence, heat, cold, change of climate; and the physiological agencies of food, or in other words on changes in the physical environment, as well as in the biological environment. Lamarck was the first one who, owing to his many years’ training in systematic botany and zoölogy, and his philosophic breadth, had stated more fully and authoritatively than any one else the results of changes in the action of the primary factors of evolution. Hence a return on the part of many in Europe, and especially in America, to Lamarckismor its modern form, Neolamarckism. Lamarck had already, so far as he could without a knowledge of modern morphology, embryology, cytology, and histology, suggested those fundamental principles of transformism on which rests the selective principle.

Had his works been more accessible, or, where available, more carefully read, and his views more fairly represented; had he been favored in his lifetime by a single supporter, rather than been unjustly criticised by Cuvier, science would have made more rapid progress, for it is an axiomatic truth that the general acceptance of a working evolutionary theory has given a vast impetus to biology.

We will now give a brief historical summary of the history of opinion held by Lamarckians regarding the causes of the “origin of the fittest,” the rise of variations, and the appearance of a population of plant and animal forms sufficiently extensive and differentiated to allow for the play of the competitive forces, and of the more passive selective agencies which began to operate in pre-cambrian times, or as soon as the earth became fitted for the existence of living beings.

The first writer after Lamarck to work along the lines he laid down was Mr. Herbert Spencer. In 1866–71, in his epochal and remarkably suggestivePrinciples of Biology, the doctrine of use and disuse is implicated in his statements as to the effects of motion on structure in general;[204]and in his theory as to the origin of the notochord, and of thesegmentation of the vertebral column and the segmental arrangement of the muscles by muscular strains,[205]he laid the foundations for future work along this line. He also drew attention in the same work to the complementary development of parts, and likewise instanced the decreased size of the jaws in the civilized races of mankind, as a change not accounted for by the natural selection of favorable variations.[206]In fact, this work is largely based on the Lamarckian principles, as affording the basis for the action of natural selection, and thirty years later we find him affirming: “The direct action of the medium was the primordial factor of organic evolution.”[207]In his well-known essay on “The Inadequacy of Natural Selection” (1893) the great philosopher, with his accustomed vigor and force, criticises the arguments of those who rely too exclusively on Darwinism alone, and especially Neodarwinism, as a sufficient factor to account for the origin of special structures as well as species.

The first German author to appreciate the value of the Lamarckian factors was that fertile and comprehensive philosopher and investigator Ernst Haeckel, who also harmonized Lamarckism and Darwinism in these words:

“We should, on account of the grand proofs just enumerated, have to adopt Lamarck’s Theory of Descent for the explanation of biological phenomena, even if we did not possess Darwin’s Theory ofSelection. The one is so completely anddirectly provedby the other, and established by mechanical causes, that there remains nothing to be desired. The laws ofInheritanceandAdaptationare universally acknowledged physiological facts, the former traceable to propagation, the latter to thenutritionof organisms. On the other hand, thestruggle for existenceis abiologicalfact, which with mathematical necessity follows from the general disproportion between the average number of organic individuals and the numerical excess of their germs.”[208]

A number of American naturalists at about the same date, as the result of studies in different directions, unbiassed by a too firm belief in the efficacy of natural selection, and relying on the inductive method alone, worked away at the evidence in favor of the primary factors of evolution along Lamarckian lines, though quite independently, for at first neither Hyatt nor Cope had read Lamarck’s writings.

In 1866 Professor A. Hyatt published the first of a series of classic memoirs on the genetic relations of the fossil cephalopods. His labors, so rich in results, have now been carried on for forty years, and are supplemented by careful, prolonged work on the sponges, on the tertiary shells of Steinheim, and on the land shells of the Hawaiian Islands.

His first paper was on the parallelism between the different stages of life in the individual and those of the ammonites, carrying out D’Orbigny’s discovery of embryonic, youthful, adult, and old-age stages in ammonites,[209]and showing that these forms aredue to an acceleration of growth in the mature forms, and a retardation in the senile forms.

In a memoir on the “Biological Relations of the Jurassic Ammonites,”[210]he assigns the causes of the progressive changes in these forms, the origination of new genera, and the production of young, mature, and senile forms to “the favorable nature of the physical surroundings, primarily producing characteristic changes which become perpetuated and increased by inheritance within the group.”

The study of the modifications of the tertiary forms of Planorbis at Steinheim, begun by Hilgendorf, led among others (nine in all) to the following conclusions:

“First, that the unsymmetrical spiral forms of the shells of these and of all the Mollusca probably resulted from the action of the laws of heredity, modified by gravitation.“Second, that there are many characteristics in these shells and in other groups, which are due solely to the uniform action of the physical influence of the immediate surroundings, varying with every change of locality, but constant and uniform within each locality.“Third, that the Darwinian law of Natural Selection does not explain these relations, but applies only to the first stages in the establishment of the differences between forms or species in the same locality. That its office is to fix these in the organization and bring them within the reach of the laws of heredity.”

“First, that the unsymmetrical spiral forms of the shells of these and of all the Mollusca probably resulted from the action of the laws of heredity, modified by gravitation.

“Second, that there are many characteristics in these shells and in other groups, which are due solely to the uniform action of the physical influence of the immediate surroundings, varying with every change of locality, but constant and uniform within each locality.

“Third, that the Darwinian law of Natural Selection does not explain these relations, but applies only to the first stages in the establishment of the differences between forms or species in the same locality. That its office is to fix these in the organization and bring them within the reach of the laws of heredity.”

These views we find reiterated in his laterpalæontological papers. Hyatt’s views on acceleration were adopted by Neumayr.[211]Waagen,[212]from his studies on the Jurassic cephalopods, concludes that the factors in the evolution of these forms were changes in external conditions, geographical isolation, competition, and that the fundamental law was not that of Darwin, but “the law of development.” Hyatt has also shown that at first evolution was rapid. “The evolution is a purely mechanical problem in which the action of the habitat is the working agent of all the major changes; first acting upon the adult stages, as a rule, and then through heredity upon the earlier stages in successive generations.” He also shows that as the primitive forms migrated and occupied new, before barren, areas, where they met with new conditions, the organisms “changed their habits and structures rapidly to accord with these new conditions.”[213]

While the palæontological facts afford complete and abundant proofs of the modifying action of changes in the environment, Hyatt, in 1877, from his studies on sponges,[214]shows that the origin of their endless forms “can only be explained by the action of physical surroundings directly working upon the organization and producing by such direct action the modifications or common variations above described.”

Mr. A. Agassiz remarks that the effect of the nature of the bottom of the sea on sponges and rhizopods “is an all-important factor in modifying the organism.”[215]

While Hyatt’s studies were chiefly on the ammonites, molluscs, and existing sponges, Cope was meanwhile at work on the batrachians. HisOrigin of Generaappeared shortly after Hyatt’s first paper, but in the same year (1866). This was followed by a series of remarkably suggestive essays based on his extensive palæontological work, which are in part reprinted in hisOrigin of the Fittest(1887); while in his epoch-making book,The Primary Factors of Organic Evolution(1896), we have in a condensed shape a clear exposition of some of the Lamarckian factors in their modern Neolamarckian form.

In the Introduction, p. 9, he remarks:

“In these papers by Professor Hyatt and myself is found the first attempt to show by concrete examples of natural taxonomy that the variations that result in evolution are not multifarious or promiscuous, but definite and direct, contrary to the method which seeks no origin for variations other than natural selection. In other words, these publications constitute the first essays in systematic evolution that appeared. By the discovery of the paleontologic succession of modifications of the articulations of the vertebrate, and especially mammalian, skeleton, I first furnished an actual demonstration of the reality of the Lamarckian factor of use, or motion, as friction, impact, and strain, as an efficient cause of evolution.”[216]

The discussion in Cope’s work of kinetogenesis, or of the effects of use and disuse, affords an extensive series of facts in support of these factors of Lamarck’s. As these two books are accessible to every one, we need only refer the reader to them as storehouses of facts bearing on Neolamarckism.

The present writer, from a study of the development and anatomy of Limulus and of Arthropod ancestry, was early (1870)[217]led to adopt Lamarckian views in preference to the theory of Natural Selection, which never seemed to him adequate or sufficiently comprehensive to explain the origin of variations.

In the following year,[218]from a study of the insects and other animals of Mammoth Cave, we claimed that “the characters separating the genera and species of animals are those inherited from adults, modified by their physical surroundings and adaptations to changing conditions of life, inducing certain alterations in parts which have been transmitted with more or less rapidity, and become finally fixed and habitual.”

In an essay entitled “The Ancestry of Insects”[219](1873) we adopted the Lamarckian factors of change of habits and environment, of use and disuse, to account for the origin of the appendages, while we attributed the origin of the metamorphoses of insects to change of habits or of the temperature of the seasons and of climates, particularly the change in the earth’s climates from the earlier ages of the globe, “when the temperature of the earth was nearly the same the world over, to the times of the present distribution of heat and cold in zones.”

From further studies on cave animals, published in 1877,[220]we wrote as follows:

“In the production of these cave species, the exceptional phenomena of darkness, want of sufficient food, and unvarying temperature, have been plainly enoughveræ causæ. To say that the principle of natural selection accounts for the change of structure is no explanation of the phenomena; the phrase has to the mind of the writer no meaning in connection with the production of these cave forms, and has as little meaning in accounting for the origination of species and genera in general. Darwin’s phrase ‘natural selection,’ or Herbert Spencer’s term ‘survival of the fittest,’ expresses simply the final result, while the process of the origination of the new forms which have survived, or been selected by nature, is to be explained by the action of the physical environments of the animals coupled with inheritance-force. It has always appeared to the writer that the phrases quoted above have been misused to state the cause, when they simply express the result of the action of a chain of causes which we may, with Herbert Spencer, call the‘environment’ of the organism undergoing modification; and thus a form of Lamarckianism, greatly modified by recent scientific discoveries, seems to meet most of the difficulties which arise in accounting for the origination of species and higher groups of organisms. Certainly ‘natural selection’ or the ‘survival of the fittest’ is not avera causa, though the ‘struggle for existence’ may show us the causes which have led to thepreservationof species, while changes in the environment of the organism may satisfactorily account for the original tendency to variation assumed by Mr. Darwin as the starting-point where natural selection begins to act.”

In our work onThe Cave Animals of North America,[221]after stating that Darwin in hisOrigin of Speciesattributed the loss of eyes “wholly to disuse,” remarking (p. 142) that after the more or less perfect obliteration of the eyes, “natural selection will often have effected other changes, such as an increase in the length of the antennæ or palpi, as a compensation for blindness,” we then summed up as follows the causes of the production of cave faunæ in general:

“1. Change in environment from light, even partial, to twilight or total darkness, and involving diminution of food, and compensation for the loss of certain organs by the hypertrophy of others.“2. Disuse of certain organs.“3. Adaptation, enabling the more plastic forms to survive and perpetuate their stock.“4. Isolation, preventing intercrossing with out-of-door forms, thus insuring the permanency of the new varieties, species, or genera.“5. Heredity, operating to secure for the future the permanence of the newly originated forms as long as the physical conditions remain the same.“Natural selection perhaps expresses the total result of the working of these five factors rather than being an efficient cause in itself, or at least constitutes the last term in a series of causes. Hence Lamarckism in a modern form, or as we have termed it, Neolamarckism, seems to us to be nearer the truth than Darwinism proper or natural selection.”[222]

“1. Change in environment from light, even partial, to twilight or total darkness, and involving diminution of food, and compensation for the loss of certain organs by the hypertrophy of others.

“2. Disuse of certain organs.

“3. Adaptation, enabling the more plastic forms to survive and perpetuate their stock.

“4. Isolation, preventing intercrossing with out-of-door forms, thus insuring the permanency of the new varieties, species, or genera.

“5. Heredity, operating to secure for the future the permanence of the newly originated forms as long as the physical conditions remain the same.

“Natural selection perhaps expresses the total result of the working of these five factors rather than being an efficient cause in itself, or at least constitutes the last term in a series of causes. Hence Lamarckism in a modern form, or as we have termed it, Neolamarckism, seems to us to be nearer the truth than Darwinism proper or natural selection.”[222]

In an attempt to apply Lamarck’s principle of the origin of the spines and horns of caterpillars and other insects as well as other animals to the result of external stimuli,[223]we had not then read what he says on the subject. (See p. 316.) Having, however, been led to examine into the matter, from the views held by recent observers, especially Henslow, and it appearing that Lamarck was substantially correct in supposing that the blood (his “fluids”) would flow to parts on the exposed portions of the body and thus cause the origin of horns, on the principle of the saying, “ubi irritatio, ibi affluxus,” we came to the following conclusions:

“The Lamarckian factors (1) change (both direct and indirect) in themilieu, (2) need, and (3) habit, and the now generally adopted principle that a change of function induces change in organs,[224]and in some or many cases actually induces the hypertrophy and specialization of what otherwise would be indifferent parts or organs;—these factors are all-important in the evolution of the colors, ornaments, and outgrowths from the cuticle of caterpillars.”

Our present views as to the relations between the Lamarckian factors and the Darwinian one of natural selection are shown by the following summary at the end of this essay.

“1. The more prominent tubercles, and spines or bristles arising from them, are hypertrophied piliferous warts, the warts, with the seta or hair which they bear, being common to all caterpillars.“2. The hypertrophy or enlargement was probably [we should rather saypossibly] primarily due to a change of station from herbs to trees, involving better air, a more equable temperature, perhaps a different and better food.“3. The enlarged and specialized tubercles developed more rapidly on certain segments than on others, especially the more prominent segments, because the nutritive fluids would tend more freely to supply parts most exposed to external stimuli.“4. The stimuli were in great part due to the visits of insects and birds, resulting in a mimicry of the spines and projections on the trees; the colors(lines and spots) were due to light or shade, with the general result of protective mimicry, or adaptation to tree-life.“5. As the result of some unknown factor some of the hypodermic cells at the base of the spines became in certain forms specialized so as to secrete a poisonous fluid.“6. After such primitive forms, members of different families, had become established on trees, a process of arboreal segregation or isolation would set in, and intercrossing with low-feeders would cease.“7. Heredity, or the unknown factors of which heredity is the result, would go on uninterruptedly, the result being a succession of generations perfectly adapted to arboreal life.“8. Finally the conservative agency of natural selection operates constantly, tending towards the preservation of the new varieties, species, and genera, and would not cease to act, in a given direction, so long as the environment remained the same.“9. Thus in order to account for the origin of a species, genus, family, order, or even a class, the first steps, causing the origination of variations, were in the beginning due to the primary (direct and indirect) factors of evolution (Neolamarckism), and the final stages were due to the secondary factors, segregation and natural selection (Darwinism).”

“1. The more prominent tubercles, and spines or bristles arising from them, are hypertrophied piliferous warts, the warts, with the seta or hair which they bear, being common to all caterpillars.

“2. The hypertrophy or enlargement was probably [we should rather saypossibly] primarily due to a change of station from herbs to trees, involving better air, a more equable temperature, perhaps a different and better food.

“3. The enlarged and specialized tubercles developed more rapidly on certain segments than on others, especially the more prominent segments, because the nutritive fluids would tend more freely to supply parts most exposed to external stimuli.

“4. The stimuli were in great part due to the visits of insects and birds, resulting in a mimicry of the spines and projections on the trees; the colors(lines and spots) were due to light or shade, with the general result of protective mimicry, or adaptation to tree-life.

“5. As the result of some unknown factor some of the hypodermic cells at the base of the spines became in certain forms specialized so as to secrete a poisonous fluid.

“6. After such primitive forms, members of different families, had become established on trees, a process of arboreal segregation or isolation would set in, and intercrossing with low-feeders would cease.

“7. Heredity, or the unknown factors of which heredity is the result, would go on uninterruptedly, the result being a succession of generations perfectly adapted to arboreal life.

“8. Finally the conservative agency of natural selection operates constantly, tending towards the preservation of the new varieties, species, and genera, and would not cease to act, in a given direction, so long as the environment remained the same.

“9. Thus in order to account for the origin of a species, genus, family, order, or even a class, the first steps, causing the origination of variations, were in the beginning due to the primary (direct and indirect) factors of evolution (Neolamarckism), and the final stages were due to the secondary factors, segregation and natural selection (Darwinism).”

From a late essay[225]we take the following extracts explaining our views:

“In seeking to explain the causes of a metamorphosis in animals, one is compelled to go back to theprimary factors of organic evolution, such as the change of environment, whether the factors be cosmical (gravity), physical changes in temperature, effects of increased or diminished light and shade, under- or over-nutrition, and the changes resulting from the presence or absence of enemies, or from isolation. The action of these factors, whether direct or indirect, is obvious, when we try to explain the origin or causes of the more marked metamorphoses of animals. Then come in the other Lamarckian factors of use and disuse, new needs resulting in new modes of life, habits, or functions, which bring about the origination, development, and perfection of new organs, as in new species and genera, etc., or which in metamorphic forms may result in a greater increase in the number of, and an exaggeration of the features characterizing the stages of larval life.“VI.The Adequacy of Neolamarckism.“It is not to be denied that in many instances all through the ceaseless operation of these fundamental factors there is going on a process of sifting or of selection of forms best adapted to their surroundings, and best fitted to survive, but this factor, though important, is quite subordinate to the initial causes of variation, and of metamorphic changes.“Neolamarckism,[226]as we understand this doctrine,has for its foundation a combination of the factors suggested by the Buffon and Geoffroy St. Hilaire school, which insisted on the direct action of themilieu, and of Lamarck, who relied both on the direct (plants and lowest animals) and on the indirect action of the environment, adding the important factors of need and of change of habits resulting either in the atrophy or in the development of organs by disuse or use, with the addition of the hereditary transmission of characters acquired in the lifetime of the individual.“Lamarck’s views, owing to the early date of his work, which was published in 1809, before the foundation of the sciences of embryology, cytology, palæontology, zoögeography, and in short all that distinguishes modern biology, were necessarily somewhat crude, though the fundamental factors he suggested are those still invoked by all thinkers of Lamarckian tendencies.“Neolamarckism gathers up and makes use of the factors both of the St. Hilaire and Lamarckian schools, as containing the more fundamental causes of variation, and adds those of geographical isolation or segregation (Wagner and Gulick), the effects of gravity, the effects of currents of air and of water, of fixed or sedentary as opposed to active modes of life, the results of strains and impacts (Ryder, Cope, and Osborn), the principle of change of function as inducing the formation of new structures (Dohrn), the effects of parasitism, commensalism, and of symbiosis—in short, the biological environment; together with geological extinction, natural and sexual selection, and hybridity.“It is to be observed that the Neolamarckian in relying mainly on these factors does not overlook the value of natural selection as a guiding principle, and which began to act as soon as the world became stocked with the initial forms of life, but he simply seeks to assign this principle to its proper position in the hierarchy of factors.“Natural selection, as the writer from the first has insisted, is not avera causa, an initial or impelling cause in the origination of new species and genera. It does not start the ball in motion; it only, so to speak, guides its movements down this or that incline. It is the expression, like that of “the survival of the fittest” of Herbert Spencer, of the results of the combined operation of the more fundamental factors. In certain cases we cannot see any room for its action; in some others we cannot at present explain the origin of species in any other way. Its action increased in proportion as the world became more and more crowded with diverse forms, and when the struggle for existence had become more unceasing and intense. It certainly cannot account for the origination of the different branches, classes, or orders of organized beings. It in themain simply corresponds to artificial selection; in the latter case, man selects forms already produced by domestication, the latter affording sports and varieties due to change in the surroundings, that is, soil, climate, food, and other physical features, as well as education.“In the case also of heredity, which began to operate as soon as the earliest life forms appeared, we have at the outset to invoke the principle of the heredity of characters acquired during the lifetime of lowest organisms.“Finally, it is noticeable that when one is overmastered by the dogma of natural selection he is apt, perhaps unconsciously, to give up all effort to work out the factors of evolution, or to seek to work out this or that cause of variation. Trusting too implicitly to the supposedvera causa, one may close his eyes to the effects of change of environment or to the necessity of constant attempts to discover the real cause of this or that variation, the reduction or increase in size of this or that organ; or become insensible to the value of experiments. Were the dogma of natural selection to become universally accepted, further progress would cease, and biology would tend to relapse into a stage of atrophy and degeneration. On the other hand, a revival of Lamarckism in its modern form, and a critical and doubting attitude towards natural selection as an efficient cause, will keep alive discussion and investigation, and especially, if resort be had to experimentation, will carry up to a higher plane the status of philosophical biology.”

“It is not to be denied that in many instances all through the ceaseless operation of these fundamental factors there is going on a process of sifting or of selection of forms best adapted to their surroundings, and best fitted to survive, but this factor, though important, is quite subordinate to the initial causes of variation, and of metamorphic changes.

“Neolamarckism,[226]as we understand this doctrine,has for its foundation a combination of the factors suggested by the Buffon and Geoffroy St. Hilaire school, which insisted on the direct action of themilieu, and of Lamarck, who relied both on the direct (plants and lowest animals) and on the indirect action of the environment, adding the important factors of need and of change of habits resulting either in the atrophy or in the development of organs by disuse or use, with the addition of the hereditary transmission of characters acquired in the lifetime of the individual.

“Lamarck’s views, owing to the early date of his work, which was published in 1809, before the foundation of the sciences of embryology, cytology, palæontology, zoögeography, and in short all that distinguishes modern biology, were necessarily somewhat crude, though the fundamental factors he suggested are those still invoked by all thinkers of Lamarckian tendencies.

“Neolamarckism gathers up and makes use of the factors both of the St. Hilaire and Lamarckian schools, as containing the more fundamental causes of variation, and adds those of geographical isolation or segregation (Wagner and Gulick), the effects of gravity, the effects of currents of air and of water, of fixed or sedentary as opposed to active modes of life, the results of strains and impacts (Ryder, Cope, and Osborn), the principle of change of function as inducing the formation of new structures (Dohrn), the effects of parasitism, commensalism, and of symbiosis—in short, the biological environment; together with geological extinction, natural and sexual selection, and hybridity.

“It is to be observed that the Neolamarckian in relying mainly on these factors does not overlook the value of natural selection as a guiding principle, and which began to act as soon as the world became stocked with the initial forms of life, but he simply seeks to assign this principle to its proper position in the hierarchy of factors.

“Natural selection, as the writer from the first has insisted, is not avera causa, an initial or impelling cause in the origination of new species and genera. It does not start the ball in motion; it only, so to speak, guides its movements down this or that incline. It is the expression, like that of “the survival of the fittest” of Herbert Spencer, of the results of the combined operation of the more fundamental factors. In certain cases we cannot see any room for its action; in some others we cannot at present explain the origin of species in any other way. Its action increased in proportion as the world became more and more crowded with diverse forms, and when the struggle for existence had become more unceasing and intense. It certainly cannot account for the origination of the different branches, classes, or orders of organized beings. It in themain simply corresponds to artificial selection; in the latter case, man selects forms already produced by domestication, the latter affording sports and varieties due to change in the surroundings, that is, soil, climate, food, and other physical features, as well as education.

“In the case also of heredity, which began to operate as soon as the earliest life forms appeared, we have at the outset to invoke the principle of the heredity of characters acquired during the lifetime of lowest organisms.

“Finally, it is noticeable that when one is overmastered by the dogma of natural selection he is apt, perhaps unconsciously, to give up all effort to work out the factors of evolution, or to seek to work out this or that cause of variation. Trusting too implicitly to the supposedvera causa, one may close his eyes to the effects of change of environment or to the necessity of constant attempts to discover the real cause of this or that variation, the reduction or increase in size of this or that organ; or become insensible to the value of experiments. Were the dogma of natural selection to become universally accepted, further progress would cease, and biology would tend to relapse into a stage of atrophy and degeneration. On the other hand, a revival of Lamarckism in its modern form, and a critical and doubting attitude towards natural selection as an efficient cause, will keep alive discussion and investigation, and especially, if resort be had to experimentation, will carry up to a higher plane the status of philosophical biology.”

Although now the leader of the Neodarwinians, and fully assured of the “all-sufficiency” of natural selection, the veteran biologist Weismann, whose earlier works were such epoch-making contributions to insect embryology, was, when active as aninvestigator, a strong advocate of the Lamarckian factors. In his masterly work,Studies in the Theory of Descent[227](1875), although accepting Darwin’s principle of natural selection, he also relied on “the transforming influence of direct action as upheld by Lamarck,” although he adds, “its extent cannot as yet be estimated with any certainty.” He concluded from his studies in seasonal dimorphism, “that differences of specific value can originate through the direct action of external conditions of life only.” While conceding that sexual selection plays a very important part in the markings and coloring of butterflies, he adds “that a change produced directly by climate may be still further increased by sexual selection.” He also inquired into the origin of variability, and held that it can be elucidated by seasonal dimorphism. He thus formulated the chief results of his investigations: “A species is only caused to change through the influence of changing external conditions of life, this change being in a fixed direction which entirely depends on the physical nature of the varying organism, and is different in different species or even in the two sexes of the same species.”

The influence of changes of climate on variation has been studied to especial advantage in North America, owing to its great extent, and to the fact that its territory ranges from the polar to the tropical regions, and from the Atlantic to the PacificOcean. As respects climatic variation in birds, Professor Baird first took up the inquiry, which was greatly extended, with especial relation to the formation of local varieties, by Dr. J. A. Allen,[228]who was the first to ascertain by careful measurements, and by a study of the difference in plumage and pelage of individuals inhabiting distant portions of a common habitat, the variations due to climatic and local causes.

“That varieties,” he says, “may and do arise by the action of climatic influences, and pass on to become species; and that species become, in like manner, differentiated into genera, is abundantly indicated by the facts of geographical distribution, and the obvious relation of local forms to the conditions of environment. The present more or less unstable condition of the circumstances surrounding organic beings, together with the known mutations of climate our planet has undergone in past geological ages, point clearly to the agency of physical conditions as one of the chief factors in the evolution of new forms of life. So long as the environing conditions remain stable, just so long will permanency of character be maintained; but let changes occur, however gradual or minute, and differentiations begin.” He inclines to regard the modifications as due rather to the direct action of the conditions of environment than to “the round-about process of natural selection.” He also admits thatchange of habits and food, use and disuse, are factors.

The same kind of inquiry, though on far less complete data, was extended by the present writer[229]in 1873 to the moths, careful measurements of twenty-five species of geometrid moths common to the Atlantic and Pacific coasts of North America showing that there is an increase in size and variation in shape of the wings, and in some cases in color, in the Pacific Coast over Eastern or Atlantic Coast individuals of the same species, the differences being attributed to the action of climatic causes. The same law holds good in the few Notodontian moths common to both sides of our continent. Similar studies, the results depending on careful measurements of many individuals, have recently been made by C. H. Eigenmann (1895–96), W. J. Moenkhaus (1896), and H. C. Bumpus (1896–98).

The discoveries of Owen, Gaudry, Huxley, Kowalevsky, Cope, Marsh, Filhol, Osborn, Scott, Wortmann, and many others, abundantly prove that the lines of vertebrate descent must have been the result of the action of the primary factors of organic evolution, including the principles of migration, isolation, and competition; the selective principle being secondary and preservative rather than originative.

Important contributions to dynamic evolution or kinetogenesis are the essays of Cope, Ryder, Dall, Osborn, Jackson, Scott, and Wortmann.

Ryder began in 1877 to publish a series of remarkably suggestive essays on the “mechanical genesis,” through strains, of the vertebrate limbs and teeth, including the causes of the reduction of digits. In discussing the origin of the great development of the incisor teeth of rodents, he suggested that “the more severe strains to which they were subjected by enforced or intelligently assumed changes of habit, were the initiatory agents in causing them to assume their present forms, such forms as were best adapted to resist the greatest strains without breaking.”[230]

He afterwards[231]claimed that the articulations of the cartilaginous fin-rays of the trout (Salmo fontinalis) are due to the mechanical strains experienced by the rays in use as motors of the body of the fish in the water.

In the line of inquiry opened up by Cope and by Ryder are the essays of Osborn[232]on the mechanical causes for the displacement of the elements of the feet in the mammals, and the phylogeny of the teeth. Also Professor W. B. Scott thus expresses the results of his studies:[233]

“To sum up the results of our examination of certain series of fossil mammals, one sees clearly that transformation, whether in the way of the addition of new parts or the reduction of those already present, acts justas ifthe direct action of theenvironment and the habits of the animal were the efficient cause of the change, and any explanation which excludes the direct action of such agencies is confronted by the difficulty of an immense number of the most striking coincidences.... So far as I can see, the theory of determinate variations and of use-inheritance is not antagonistic but supplementary to natural selection, the latter theory attempting no explanation of thecausesof variation. Nor is it pretended for a moment that use and disuse are the sole or even the chief factors in variation.”

As early as 1868 the Lamarckian factor of isolation, due to migration into new regions, was greatly extended, and shown by Moritz Wagner[234]to be a most important agent in the limitation and fixation of varieties and species.

“Darwin’s work,” he says, “neither satisfactorily explains the external cause which gives the first impulse to increased individual variability, and consequently to natural selection, nor that condition which, in connection with a certain advantage in the struggle for life, renders the new characteristics indispensable. The latter is, according to my conviction, solely fulfilled by the voluntary or passive migration of organisms and colonization, which depends in a great measure upon the configuration of the country; so that only under favorable conditions would the home of a new species be founded.”

This was succeeded by Rev. J. T. Gulick’s profound essays “On Diversity of Evolution under One Set of External Conditions”[235](1872), and on “Divergent Evolution through Cumulative Segregation”[236](1887).

These and later papers are based on his studies on the land shells of the Hawaiian Islands. The cause of their extreme diversity of local species is, he claims, not due to climatic conditions, food, enemies, or to natural selection, but to the action of what he calls the “law of segregation.”

Fifteen years later Mr. Romanes published his theory of physiological selection, which covered much the same ground.

A very strong little book by an ornithologist of wide experience, Charles Dixon,[237]and refreshing to read, since it is packed with facts, is Lamarckian throughout. The chief factor in the formation of local species is, he thinks, isolation; the others are climatic influences (especially the glacial period), use and disuse, and sexual selection as well as chemical agency. Dixon insists on the “vast importance of isolation in the modification of many forms of life, without the assistance of natural selection.” Again he says: “Natural selection, as has often been remarked, can only preserve a beneficial variation—it cannot originate it, it is not a cause of variation; onthe other hand, the use or disuse of organs is a direct cause of variation, and can furnish natural selection with abundance of material to work upon” (p. 49). The book, like the papers of Allen, Ridgway, Gulick, and others, shows the value of isolation or segregation in special areas as a factor in the origination of varieties and species, the result being the prevention of interbreeding, which would otherwise swamp the incipient varieties.

Here might be cited Delbœuf’s law:[238]

“When a modification is produced in a very small number of individuals, this modification, even were it advantageous, would be destroyed by heredity, as the favored individuals would be obliged to unite with the unmodified individuals.Il n’en est rien, cependant.However great may be the number of forms similar to it, and however small may be the number of dissimilar individuals which would give rise to an isolated individual, we can always, while admitting that the different generations are propagated under the same conditions, meet with a number of generations at the end of which the sum total of the modified individuals will surpass that of the unmodified individuals.” Giard adds that this law is capable of mathematical demonstration. “Thus the continuity or even the periodicity of action of a primary factor, such, for example, as a variation of themilieu, shows us the necessary and sufficient condition under which a variety or species originates without the aid of any secondary factor.”

Semper,[239]an eminent zoölogist and morphologist,who also was the first (in 1863) to criticise Darwin’s theory of the mode of formation of coral atolls, though not referring to Lamarck, published a strong, catholic, and original book, which is in general essentially Lamarckian, while not undervaluing Darwin’s principle of natural selection. “It appears to me,” he says, in the preface, “that of all the properties of the animal organism, Variability is that which may first and most easily be traced by exact investigation to its efficient causes.”

“By a rearrangement of the materials of his argument, however, we obtain, as I conceive, convincing proof that external conditions can exert not only a very powerful selective force, but a transforming one as well, although it must be the more limited of the two.“An organ no longer needed for its original purpose may adapt itself to the altered circumstances, and alter correspondingly if it contains within itself, as I have explained above, the elements of such a change. Then the influence exerted by the changed conditions will betransforming, notselective.“This last view may seem somewhat bold to those readers who know that Darwin, in his theory of selection, has almost entirely set aside the direct transforming influence of external circumstances. Yet he seems latterly to be disposed to admit that he had undervalued the transforming as well as the selective influence of external conditions; and it seems to me that his objection to the idea of such an influence rested essentially on the method of his argument, which seemed indispensable for setting his theory of selection and his hypothesis as to the transformation of species in a clear light and on a firm footing” (p. 37).

“An organ no longer needed for its original purpose may adapt itself to the altered circumstances, and alter correspondingly if it contains within itself, as I have explained above, the elements of such a change. Then the influence exerted by the changed conditions will betransforming, notselective.

“This last view may seem somewhat bold to those readers who know that Darwin, in his theory of selection, has almost entirely set aside the direct transforming influence of external circumstances. Yet he seems latterly to be disposed to admit that he had undervalued the transforming as well as the selective influence of external conditions; and it seems to me that his objection to the idea of such an influence rested essentially on the method of his argument, which seemed indispensable for setting his theory of selection and his hypothesis as to the transformation of species in a clear light and on a firm footing” (p. 37).

Dr. H. de Varigny has carried on much farther the kind of experiments begun by Semper. In hisExperimental Evolutionhe employs the Lamarckian factors of environment and use and disuse, regarding the selective factors as secondary.

The Lamarckian factors are also depended upon by the late Professor Eimer in his works on the variation of the wall-lizard and on the markings of birds and mammals (1881–88), his final views being comprised in his general work.[240]The essence of his point of view may be seen by the following quotation:

“According to my conception, the physical and chemical changes which organisms experience during life through the action of the environment, through light or want of light, air, warmth, cold, water, moisture, food, etc., and which they transmit by heredity, are the primary elements in the production of the manifold variety of the organic world, and in the origin of species. From the materials thus supplied the struggle for existence makes its selection. These changes, however, express themselves simply as growth” (p. 22).

In a later paper[241]Eimer proposes the term “orthogenesis,” or direct development, in rigorous conformity to law, in a few definite directions. Although this is simply and wholly Lamarckism, Eimer claims that it is not, “for,” he strangely enough says, “Lamarck ascribed no efficiency whatever tothe effects of outward influences on the animal body, and very little to their effects upon vegetable organisms.” Whereas if he had read his Lamarck carefully, he would have seen that the French evolutionist distinctly states that the environment acts directly on plants and the lower animals, but indirectly on those animals with a brain, meaning the higher vertebrates. The same anti-selection views are held by Eimer’s pupil, Piepers,[242]who explains organic evolution by “laws of growth, ... uncontrolled by any process of selection.”

Dr. Cunningham likewise, in the preface to his translation of Eimer’s work, gives his reasons for adopting Neolamarckian views, concluding that “the theory of selection can never get over the difficulty of the origin of entirely new characters;” that “selection, whether natural or artificial, could not be the essential cause of the evolution of organisms.” In an article on “The New Darwinism” (Westminster Review, July, 1891) he claims that Weismann’s theory of heredity does not explain the origin of horns, venomous teeth, feathers, wings of insects, or mammary glands, phosphorescent organs, etc., which have arisen on animals whose ancestors never had anything similar.

Discussing the origin of whales and other aquatic mammals, W. Kükenthal suggests that the modifications are partially attributable to mechanical principles. (Annals and Mag. Nat. Hist., February, 1891.)

From his studies on the variation of butterflies,Karl Jordan[243]proposes the term “mechanical selection” to account for them, but he points out that this factor can only work on variations produced by other factors. Certain cases, as the similar variation in the same locality of two species of different families, but with the same wing pattern, tell in favor of the direct action of the local surroundings on the markings of the wings.

In the same direction are the essays of Schroeder[244]on the markings of caterpillars, which he ascribes to the colors of the surroundings; of Fischer[245]on the transmutations of butterflies as the result of changes of temperature, and also Dormeister’s[246]earlier paper. Steinach[247]attributes the color of the lower vertebrates to the direct influence of the light on the pigment cells, as does Biedermann.[248]

In his address on evolution and the factors of evolution, Professor A. Giard[249]has given due credit to Lamarck as “the creator of transformism,” and to the position to be assigned to natural selection as a secondary factor. He quotes at length Lamarck’sviews published in 1806. After enumerating the primary factors of organic evolution, he places natural selection among his secondary factors, such as heredity, segregation, amixia, etc. On the other hand, he states that Lamarck was not happy in the choice of the examples which he gave to explain the action of habits and use of parts. “Je ne rappellerai par l’histoire tant de fois critique du cou de la giraffe et des cornes de l’escargot.”

Another important factor in the evolution of the metazoa or many-celled animals, from the sponges and polyps upward from the one-celled forms or protozoa, is the principle of animal aggregation or colonization advanced by Professor Perrier. As civilization and progressive intelligence in mankind arose from the aggregation of men into tribes or peoples which lived a sedentary life, so the agricultural, building, and other arts forthwith sprang up; and as the social insects owe their higher degree of intelligence to their colonial mode of life, so as soon as unicellular organisms began to become fixed, and form aggregates, the sponge and polyp types of organization resulted, this leading to the gastræa, or ancestral form from which all the higher phyla may have originated.

M. Perrier appears to fully accept Lamarck’s views, including his speculations as to wants, and use and disuse. He, however, refuses to accept Lamarck’s extreme view as to the origin through effort of entirely new organs. As he says: “Unfortunately, if Lamarck succeeded in explaining in a plausible way the modification of organs already existing, their adaptation to different uses, or even theirdisappearance from disuse, in regard to the appearance of new organs he made hypotheses so venturesome that they led to the momentary forgetfulness of his other forceful conceptions.”[250]

The popular idea of Lamarckism, and which from the first has been prejudicial to his views, is that an animal may acquire an organ by simply wishing for or desiring it, or, as his French critics put it, “Un animal finit toujours par posséder un organe quand il le veut.” “Such,” says Perrier,[251]“is not the idea of Lamarck, who simply attributes the transformations of species to the stimulating action of external conditions, construing it under the expression of wants (besoins), and explaining by that word what we now calladaptations. Thus the long neck of the giraffe results from the fact that the animal inhabits a country where the foliage is situated at the tops of high trees; the long legs of the wading birds have originated from the fact that these birds are obliged to seek their food in the water without wetting themselves,” etc. (See p. 350.)

“Many cases,” says Perrier, “may be added to-day to those which Lamarck has cited to support his first law [pp. 303, 346]; the only point which is open to discussion is the extent of the changes which an organ may undergo, through the use it is put to by the animal. It is a simple question of measurement. The possibility of the creation of an organ inconsequence of external stimuli is itself a matter which deserves to be studied, and which we have no right to reject without investigation, without observations, or to treat as a ridiculous dream; Lamarck would doubtless have made it more readily accepted, if he had not thought it well to pass over the intermediate steps by means of wants. It is incontestable that by lack of exercise organs atrophy and disappear.”Finally, says Perrier: “Without doubt the real mechanism of the improvement (perfectionnement) of organisms has escaped him [Lamarck], but neither has Darwin explained it. The law of natural selection is not the indication of a process of transformation of animals; it is the expression of the total results. It states these results without showing us how they have been brought about. We indeed see that it tends to the preservation of the most perfect organisms; but Darwin does not show us how the organisms themselves originated. This is a void which we have only during these later years tried to fill” (p. 90).

Finally, says Perrier: “Without doubt the real mechanism of the improvement (perfectionnement) of organisms has escaped him [Lamarck], but neither has Darwin explained it. The law of natural selection is not the indication of a process of transformation of animals; it is the expression of the total results. It states these results without showing us how they have been brought about. We indeed see that it tends to the preservation of the most perfect organisms; but Darwin does not show us how the organisms themselves originated. This is a void which we have only during these later years tried to fill” (p. 90).

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