;66 



NATURE 



[February 14, igor 



The second lecture, " The New Darwinism," contains at 

 the outset (p. 63) an entirely new and erroneous definition 

 of the term " Neo- Darwinian." "The Neo-Darwinians, 

 as we are sometimes called, accept Darwin's teaching, 

 and supplement the theory of natural selection with 

 methods of isolation " (italics the author's). As is well 

 known, the term was really applied to those who ac- 

 cepted only that part of Darwin's teachings which was 

 originated by him, and excluded that small but distinct 

 element of Lamarckian doctrine which he incorporated 

 with his own. The history of the use of this term 

 and " Neo-Lamarckian" is as follows. A school of 

 Lamarckian evolutionists grew up in the United 

 States, and reached its maximum about the time 

 that the question of the hereditary transmission of 

 acquired characters became acute, viz., 1887 and the 

 following years. It consisted of Cope, Hyatt, Ryder and 

 several other naturalists ; W. B. Scott and H. F. Osborn 

 belonged to it in those days. The members of the school 

 chiefly looked at evolution from the point of view of 

 palaeontology. They called themselves Neo-Lamarckians, 

 because they rejected Lamarck's more extravagant 

 suggestions, but believed that in the remainder they had 

 found a satisfactory basis for evolution. When, owing 

 to Weismann's writings, the scope of heredity began to be 

 rigidly investigated, many naturalists quickly recognised 

 that grave doubt was thrown upon the whole of Buffon's 

 and Lamarck's suggestions as to the causes of evolution, 

 and they took their stand on natural selection alone 

 among all hypotheses as yet proposed. In this they fol- 

 lowed Weismann and Wallace, and they were called by 

 those who did not agree with them " Weismannians " or 

 " Neo-Darwiniahs," the term " Darwinian " being reserved 

 for those who believed the whole of Darwin's teaching — 

 the extrinsic element as well as that peculiar to him. This 

 at any rate, was the attempted achievement of the 

 ,labellers. The naturalists in question had never selected 

 the label which it was sought to affix to them, nor were 

 they pleased with it, as were the Neo-Lamarckians with 

 their invention. They, or at any rate -many of them, pro- 

 tested against the term " Darwinism " being used neces- 

 sarily to include an element extraneous to Darwin, 

 although accepted by him, of very doubtful validity, and 

 liable, if entirely abandoned, to drag down with it the 

 historic title derived from the name of the great English 

 naturalist. "Darwinism," applied, as Wallace applies 

 it, to the hypothesis which was originated by Darwin, 

 is hable to no such objection, and these naturalists 

 maintained that it is in every way appropriate to thus 

 describe natural selection,the one and onlysuggested cause 

 of evolution which seemed to them to possess any sig- 

 nificance or value. The history of the whole controversy 

 is to be found in letters and articles printed in this journal 

 for several years following 1887. 



In this second lecture many examples are given of 

 what are believed to be useless specific characters (p. 69- 

 73). The exigencies of space prevent any detailed 

 criticism, but it may be generally stated that many of the 

 cases cited are extremely unconvincing. The question of 

 incipient variations is briefly alluded to without any 

 reference to Dohrn's principle of "change of function,'' 

 which offers so probable an explanation of many 

 difficulties. 



NO. 1 63 J, VOL. 63] 



One of the best features of the book is the use made of 

 the natural history of New Zealand and the southern 

 seas (as on pp. 87, 90, 91, &c.). 



In the third lecture, "Darwinism in Human Affairs, " 

 there is a clear statement of the way in which selection 

 acts on a group of competing individuals distinguished 

 by variation (pp. no, in). The concluding sentence of 

 the lecture, on p. 133, is distinctly out of place in a work of 

 this kind. Those who have written on the relations of 

 religious thought and doctrine to the teachings of 

 science have always been welcomed by a large body of 

 readers. But it is unwise, and, fortunately, rare, for the 

 two sets of ideas to be jumbled together haphazard, so 

 that in a professedly scientific work we are suddenly 

 brought up with a shock by some short sentence express- 

 ing a religious conviction. The object which the author 

 probably has in view is not advanced by such a method. 



The concluding lecture, on " The New Lamarckism," 

 contains much cautious and interesting reasoning upon 

 various instances which are believed to prove the exist- 

 ence of the Lamarckian factors of evolution ; although 

 the part which the nervous system probably plays in 

 many of the changes, such as those of pupae (p. 141) and 

 of mammalian hair (p. 142), is neglected. The opinion 

 that retrogression follows as a natural result of the 

 cessation of selection is rejected by the author (p. 157), 

 as we might expect, seeing that he does not allude to 

 the conception of a condition of unprogressive equili- 

 brium still requiring the unremitting aid of selection for 

 its support. In this lecture, too, there is a further dog- 

 matic statement as to the uselessness of certain structures 

 or features. Among these the white under-side of flat 

 fishes is instanced as probably due to disuse-inherit- 

 ance (.p. 160) ; but Abbott H. Thayer's interpretation of 

 white under-sides generally may very probably be 

 applied (as, indeed, Mr. Thayer believes) during the 

 movements of these fish. The statement that " the 

 thickness of the legs of the moas was of no advantage to 

 them. On the contrary,, it was distinctly a disadvan- 

 tage" (p. 160), is an example of dogmatism concerning 

 conditions of life of which we are extremely ignorant. 



The author is inclined to believe in certain examples 

 of "disuse-inheritance," although he generally criticises 

 the evidence for " use-inheritance." He forgets that pas- 

 sive structures which are useful, but not physiologically 

 altered by their own utility, degenerate when they cease 

 to be useful, no less than the active structures which are 

 modified by their own use.. This argument, niutalis 

 mutandis, affects equally the supposed use-inheritance. 



In the case of certain New Zealand alpine plants, it 

 is contended that there is good evidence for the trans- 

 mission of an acquired character. Olearia 7iummulari- 

 folia, var. cymbifolia, produces leaves characteristic of 

 the local alpme plants, but " the leaves on new shoots 

 revert to the- ordinary form if the plant is removed to the 

 low land ; thus showing that the peculiar shaped leaf is 

 an acquired character and not inherited." On the other 

 hand, tlie alpine Veronica lycopodtoides, having a leaf 

 similar to that of the Olearia, does not change when 

 grown at a low level, "and we must, therefore, assume 

 that an acquired character has here become congenital" 

 (p. 165). The probable explanation is that natural 

 selection has rendered the former species susceptible to 



