^ Oct. lo, 1889] 



NATURE 



567 



-well serve as an introduction to the study of that and the 

 other works of Darwin — the value of which, not only as 

 storehouses of fact and suggestion, but as classical models 

 of scientific discussion, cannot be over-estimated, and 

 will probably never be surpassed. 



In his preface, Mr. Wallace, through a misconception 

 which is perhaps explained by the retired life which he 

 enjoys — makes an attack upon what he calls "the modern 

 school of laboratory naturalists." He states that these 

 persons seek to minimize the agency of natural selection 

 and to subordinate it to laws of variation, of use and disuse, 

 of intelligence and heredity. He commends, as leading 

 to truer views, the study of the external and vital relations 

 of species to species in a state of nature — a study which 

 Semper has called " the physiology of organisms," and 

 I have proposed in the article " Zoology " in the " Encyclo- 

 paedia Britannica " to call " bionomics." Now though there 

 is no doubt an increasing number of younger students who 

 have little or no interest in natural history beyond what 

 is derived from the contemplation of ribbons of sections 

 dyed like Joseph's coat, yet it is going too far to say that 

 they have in any sense formed a school. And further, if 

 we endeavour to estimate the influence on naturalists of a 

 considerable devotion of time to the study in the labor- 

 latory of histology and embryology, physiology and 

 ;morphology, we shall be led to the conclusion that this 

 [Study has been associated with exactly opposite results 

 from those attributed to it by Mr. Wallace. Who are 

 they who seek to minimize natural selection and to set 

 up the false gods of variation, use and disuse, &c. ? 

 Certainly not laboratory men. Is the Duke of Argyll a 

 laboratory naturalist ? Is Dr. George Romanes ? Is 

 Prof. Cope? Are Mr. Herbert Spencer and Prof. Patrick 

 Geddes ? I venture to say they are not ; yet they are the 

 authors with whom Mr. Wallace has subsequently to 

 :ontend when he maintains that the selection of con- 

 jejiital variations by natural selection is an adequate 

 heory of the origin of species, and requires no aid from 

 amarckism, Copism, or other interlopers. Who are 

 hey who agree with Mr. Wallace in this contention ? 

 'recisely " laboratory men," who are, however, by no 

 oeans only laboratory men, but, like Darwin himself, 

 earch for their material in the garden, the field, the sea- 

 |hore, or the sea-bottom ; and as a part — but only a part 

 f their study of it eventually bring it to the laboratory. 

 uch a " laboratory naturalist " is Weismann, whose 

 ssays and memoirs in favour of the identical view main- 

 ined by Mr. Wallace, appear to have escaped his 

 [ttention until very recently. I presume also that I may 

 aim to be a laboratory naturalist ; and yet four years ago 

 found it necessary, in lectures dehvered at the London 

 stitution, to discard even that tincture of Lamarckism 

 hich Darwin had admitted, and to advocate " pure 

 arwinism," on the ground that the Lamarckian hypo- 

 esis is still devoid of experimental basis, and in view of 

 e logical principal Entia non sunt multiplicanda 

 'eeter necessitatetn. It is true, as I have elsewhere 

 MSted, that there are not at present such facilities for 

 e study of bionomics as are provided in our laboratories 

 the study of histology, embryology, morphography, 

 d the physics and chemistry of living bodies. But it 

 not right to identify the class of speculations, to which 

 r. Wallace is opposed, with laboratory training. This, 



indeed, in virtue of its tending to bring speculation to the 

 test of fact, is favourable, and often directly conducive, to 

 the study of " the external and vital relations of species 

 to species in a state of nature," or in one word " biono- 

 mics." I will only cite as instances Bateson's researches in 

 Tartary, Caldwell's in Australia, Poulton's experiments on 

 insects, and Moseley's " Notes of a Naturalist on the 

 Challenger." 



Mr. Wallace's plan of treatment of his subject is an 

 excellent one. After a brief statement of what naturalists 

 have understood by the word " species," and a lucid 

 exposition of the views of the earlier transmutationists, 

 he enunciates Darwin's theory. He then proceeds to 

 show, by citing a wide and comprehensive array of facts, 

 that the foundations of the theory are secure. In one 

 chapter he describes the rapid multiplication of organisms 

 and the consequent struggle for existence ; in further, 

 chapters the fact of variability is shown, by an appeal to 

 instances, to be one of the widest and most general 

 character ; in another chapter the facts of heredity and 

 selection are brought forward. Then follow discussions 

 of "difficulties and objections," hybridity, the origin 

 and use of colour in animals and in plants, geographical 

 distribution, the geological evidences of evolution, the 

 fundamental problems of variation and heredity, and, 

 lastly, Darwinism applied to man. 



The chapter on " Variability of Species in a State of 

 Nature" is one on which considerable pains has been 

 expended. It presents some of the facts of variation in 

 a very striking manner, and provides us with a number 

 of well-studied instances which have not before been 

 accessible to naturalists. A method followed by Mr. 

 Wallace is to take any large collection of a single species 

 and to measure various parts, such as length of head, tail, 

 limb, &c. As he observes, it is very important to convince 

 ourselves that variation does occur in a state of nature, 

 so that natural selection has the material to act upon. 

 He considers that the instances which he brings forward 

 show that the range of variation is larger and more general 

 in a state of nature than is usually assumed, and that " it 

 is clear that Mr. Darwin himself did not fully recognize 

 the enormous amount of variability that actually exists." 

 Whilst admitting the interest of Mr. Wallace's present 

 contribution to this subject, I think it is clear that he 

 has failed to make a distinction which is desirable and 

 important, viz. that between variations exhibited by adult 

 specimens and the variability presented by the young of 

 any given species. After all, the specimens of lizards and 

 birds, of which the measurements are given to us by Mr. 

 Wallace, only comprise such individuals as were not too 

 widely divergent from the parent form to survive to 

 maturity under conditions which select more or less 

 closely a given specific set of characters. What one would 

 like to know is the actual range of variability as shown 

 by the artificial rearing of all the offspring of a single pair. 

 With plants such a study of variation is practicable, but 

 less so with animals. Variation includes those extreme 

 cases which are called " monstrosities," and it is by no 

 means certain that natural selection would always exclude 

 these extreme cases from survival. The facts of variation 

 under domestication are more to the point, in so far as 

 the range of congenital variability is concerned, since in 

 regard to a limited number of animals and plants we have 



