Lang"s treatment, in his _Text-book of Comparative Anatomy_ (1888), of the subjects of the musculature of worms and crustacea, and of the mechanism of the motion of the segmented body in the Arthropoda, is of much value in relation to the mechanical genesis of the body segments and limbs of the members of this type. Dr. B. Sharp has also discussed the same subject (_American Naturalist_, 1893, p. 89), also Graber in his works, while the present writer in his _Text-book of Entomology_ (1898) has attempted to treat of the mechanical origin of the segments of insects, and of the limbs and their jointed structure, along the lines laid down by Herbert Spencer, Lang, Sharp, and Graber.
W. Roux[263] has inquired how natural selection could have determined the special orientation of the sheets of spongy tissue of bone. He contends that the selection of accidental variation could not originate species, because such variations are isolated, and because, to const.i.tute a real advantage, they should rest on several characters taken together. His example is the transformation of aquatic into terrestrial animals.
G. Pfeffer[264] opposes the efficacy of natural selection, as do C.
Emery[265] and O. Hertwig. The essence of Hertwig"s _The Biological Problem of To-day_ (1894) is that "in obedience to different external influences the same rudiments may give rise to different adult structures" (p. 128). Delage, in his _Theories sur l"Heredite_, summarizes under seven heads the objections of these distinguished biologists. Species arise, he says, from general variations, due to change in the conditions of life, such as food, climate, use and disuse, very rarely individual variations, such as sports or aberrations, which are more or less the result of disease.
Mention should also be made of the essays and works of H. Driesch,[266]
De Varigny,[267] Danilewsky,[268] Verworn,[269] Davenport,[270]
Gadow,[271] and others.
In his address on "Neodarwinism and Neolamarckism," Mr. Lester F. Ward, the palaeobotanist, says:
"I shall be obliged to confine myself almost exclusively to the one great mind, who far more than all others combined paved the way for the new science of biology to be founded by Darwin, namely, Lamarck." After showing that Lamarck established the functional, or what we would call the dynamic factors, he goes on to say that "Lamarck, although he clearly grasped the law of compet.i.tion, or the struggle for existence, the law of adaptation, or the correspondence of the organism to the changing environment, the trans.m.u.tation of species, and the genealogical descent of all organic beings, the more complex from the more simple; he nevertheless failed to conceive the selective principle as formulated by Darwin and Wallace, which so admirably complemented these great laws."[272]
As is well known, Huxley was, if we understand his expressions aright, not fully convinced of the entire adequacy of natural selection.
"There is no fault to be found with Mr. Darwin"s method, then; but it is another question whether he has fulfilled all the conditions imposed by that method. Is it satisfactorily proved, in fact, that species may be originated by selection? that there is such a thing as natural selection? that none of the phenomena exhibited by species are inconsistent with the origin of species in this way?
"After much consideration, with a.s.suredly no bias against Mr. Darwin"s views, it is our clear conviction that, as the evidence stands, it is not absolutely proven that a group of animals, having all the characters exhibited by species in nature, has ever been originated by selection, whether artificial or natural. Groups having the morphological character of species, distinct and permanent races, in fact, have been so produced over and over again; but there is no positive evidence, at present, that any group of animals has, by variation and selective breeding, given rise to another group which was even in the least degree infertile with the first. Mr. Darwin is perfectly aware of this weak point, and brings forward a mult.i.tude of ingenious and important arguments to diminish the force of the objection."[273]
We have cited the foregoing conclusions and opinions of upwards of forty working biologists, many of whom were brought up, so to speak, in the Darwinian faith, to show that the pendulum of evolutionary thought is swinging away from the narrow and restricted conception of natural selection, pure and simple, as the sole or most important factor, and returning in the direction of Lamarckism.
We may venture to say of Lamarck what Huxley once said of Descartes, that he expressed "the thoughts which will be everybody"s two or three centuries after" him. Only the change of belief, due to the rapid acc.u.mulation of observed facts, has come in a period shorter than "two or three centuries;" for, at the end of the very century in which Lamarck, whatever his crudities, vagueness, and lack of observations and experiments, published his views, wherein are laid the foundations on which natural selection rests, the consensus of opinion as to the direct and indirect influence of the environment, and the inadequacy of natural selection as an initial factor, was becoming stronger and deeper-rooted each year.
We must never forget or underestimate, however, the inestimable value of the services rendered by Darwin, who by his patience, industry, and rare genius for observation and experiment, and his powers of lucid exposition, convinced the world of the truth of evolution, with the result that it has transformed the philosophy of our day. We are all of us evolutionists, though we may differ as to the nature of the efficient causes.
FOOTNOTES:
[204] Vol. ii., p. 167, 1871.
[205] Vol. ii., p. 195.
[206] Vol. i., -- 166, p. 456.
[207] _The Factors of Organic Evolution_, 1895, p. 460.
[208] _Schopfungegeschichte_, 1868. _The History of Creation_, New York, ii., p. 355.
[209] Alcide d"Orbigny, _Paleontologie francaise_, Paris, 1840-59.
[210] Abstract in Proceedings of the Boston Society of Natural History, xvii., December 16, 1874.
[211] _Zeitschr. der deutsch. geol. Gesellschaft_, 1875.
[212] _Palaeontologica Indica_. Jura.s.sic Fauna of Kutch. I. Cephalopoda, pp. 242-243. (See Hyatt"s _Genesis of the Arietidae_, pp. 27, 42.)
[213] "Genera of Fossil Cephalopods," Proc. Bost. Soc. Nat. Hist., xxii., April 4, 1883, p. 265.
[214] "Revision of the North American Poriferae." Memoirs Bost. Soc. Nat.
Hist., ii., part iv., 1877.
[215] _Three Cruises of the "Blake,"_ 1888, ii., p. 158.
[216] The earliest paper in which he adopted the Lamarckian doctrines of use and effort was his "Methods of Creation of Organic Types" (1871). In this paper Cope remarks that he "has never read Lamarck in French, nor seen a statement of his theory in English, except the very slight notices in the _Origin of Species_ and _Chambers" Encyclopaedia_, the latter subsequent to the first reading of this paper." It is interesting to see how thoroughly Lamarckian Cope was in his views on the descent theory.
[217] Proceedings of the American a.s.sociation for the Advancement of Science, Troy meeting, 1870. Printed in August, 1871.
[218] _American Naturalist_, v., December, 1871, p. 750. See also pp. 751, 759, 760.
[219] Printed in advance, being chapter xiii. of _Our Common Insects_, Salem, 1873, pp. 172, 174, 179, 180, 181, 185.
[220] "A New Cave Fauna in Utah." _Bulletin of the United States Geological Survey_, iii., April 9, 1877, p. 167.
[221] Memoirs of the National Academy of Sciences, iv., 1888, pp. 156: 27 plates. See also _American Naturalist_, Sept., 1888, xxii., p. 808, and Sept., 1894, xxviii., p. 333.
[222] Carl H. Eigenmann, in his elaborate memoir, _The Eyes of the Blind Vertebrates of North America (Archiv fur Entwickelungsmechanik der Organismen_, 1899, viii.), concludes that the Lamarckian view, that through disuse and the transmission by heredity of the characters thus inherited the eyes of blind fishes are diminished, "is the only view so far examined that does not on the face of it present serious objections"
(pp. 605-609).
[223] "Hints on the Evolution of the Bristles, Spines, and Tubercles of Certain Caterpillars, etc." Proceedings Boston Society of Natural History, xxiv., 1890, pp. 493-560; 2 plates.
[224] E. J. Marey: "Le Transformisme et la Physiologie Experimentale, Cours du College de France," _Revue Scientifique_, 2^me serie, iv., p. 818. (Function makes the organ, especially in the osseous and muscular systems.) See also A. Dohrn: _Der Ursprung der Wirbelthiere und das Princip des Functionswechsels_, Leipzig, 1875. See also Lamarck"s opinion, p. 295.
[225] "On the Inheritance of Acquired Characters in Animals with a Complete Metamorphosis." Proceedings Amer. Acad. Arts and Sciences, Boston, xxix. (N. S., xxi.). 1894, pp. 331-370; also monograph of "Bombycine Moths," Memoirs Nat. Acad. Sciences, vii., 1895, p. 33.
[226] In 1885, in the Introduction to the _Standard Natural History_, we proposed the term Neolamarckianism, or Lamarckism in its modern form, to designate the series of factors of organic evolution, and we take the liberty to quote the pa.s.sage in which the word first occurs. We may add that the briefer form, Neolamarckism, is the more preferable.
"In the United States a number of naturalists have advocated what may be called Neo-Lamarckian views of evolution, especially the conception that in some cases rapid evolution may occur. The present writer, contrary to pure Darwinians, believes that many species, but more especially types of genera and families, have been produced by changes in the environment acting often with more or less rapidity on the organism, resulting at times in a new genus, or even a family type. Natural selection, acting through thousands, and sometimes millions, of generations of animals and plants, often operates too slowly; there are gaps which have been, so to speak, intentionally left by Nature. Moreover, natural selection was, as used by some writers, more an idea than a _vera causa_. Natural selection also begins with the a.s.sumption of a tendency to variation, and presupposes a world already tenanted by vast numbers of animals among which a struggle for existence was going on, and the few were victorious over the many. But the entire inadequacy of Darwinism to account for the primitive origin of life forms, for the original diversity in the different branches of the tree of life forms, the interdependence of the creation of ancient faunas and floras on geological revolutions, and consequent sudden changes in the environment of organisms, has convinced us that Darwinism is but one of a number of factors of a true evolution theory; that it comes in play only as the last term of a series of evolutionary agencies or causes; and that it rather accounts, as first suggested by the Duke of Argyll, for the _preservation_ of forms than for their origination. We may, in fact, compare Darwinism to the apex of a pyramid, the larger ma.s.s of the pyramid representing the complex of theories necessary to account for the world of life as it has been and now is. In other words, we believe in a modified and greatly extended Lamarckianism, or what may be called Neo-Lamarckianism."
[227] _Studies in the Theory of Descent_. By Dr. August Weismann.
Translated and edited, with notes, by Raphael Meldola. London, 1882.
2 vols.
[228] "The Influence of Physical Conditions in the Genesis of Species,"
_Radical Review_, i., May, 1877. See also J. A. Allen in Bull. Mus.
Comp. Zool. ii., 1871; also R. Ridgway, _American Journal of Science_, December, 1872, January, 1873.
[229] Annual Report of the United States Geological and Geographical Survey Territories, 1873. Pp. 543-560. See also the author"s monograph of Geometrid Moths or Phalaenidae of the United States, 1876, pp. 584-589, and monograph of Bombycine Moths (Notodontidae), p. 50.
[230] Proceedings Academy of Natural Science, Philadelphia (1877), p. 318.
[231] Proceedings of the American Philosophical Society (1889), p. 546.
[232] Transactions American Philosophical Society, xvi. (1890), and later papers.
[233] _American Journal of Morphology_ (1891), pp. 395, 398.