VI DIFFICULTIES AND OBJECTIONS 131 



the whole of the sixth and seventh chapters of the last edition 

 of The Origin of Species, in which these and many other cases 

 are discussed in considerable detail. 



Useless or non-adaptive Characters. 



Many naturalists seem to be of opinion that a considerable 

 number of the characters which distinguish species are of no 

 service whatever to their possessors, and therefore cannot have 

 been j^roduced or increased by natural selection. Professors 

 Bronn and Broca have urged this objection on the continent. 

 In America, Dr. Cope, the well-known palseontologist, has long 

 since put forth the same objection, declaring that non-adaptive 

 characters are as numerous as those which are adaptive ; but 

 he differs completely from most who hold the same general 

 opinion in considering that they occur chiefly " in the 

 characters of the classes, orders, families, and other higher 

 groups;" and the objection, therefore, is quite distinct from 

 that in which it is urged that " specific characters " are mostly 

 useless. More recently, Professor G. J. Romanes has urged this 

 difficulty in his paper on "Physiological Selection" (Journ. 

 Linn. Sac, vol. xix. pp. 338, 344). He says that the characters 

 "which serve to distinguish allied species are frec[uently, if 

 not usually, of a kind with which natural selection can have 

 had nothing to do," being without any utilitarian significance. 

 Again he speaks of " the enormous number," and further on of 

 " the innumerable multitude " of specific peculiarities which 

 are useless ; and he finally declares that the question needs no 

 further arguing, " because in the later editions of his works 

 Mr. Darwin freely acknowledges that a large proportion of 

 specific distinctions must be conceded to be useless to the 

 species presenting them." 



I have looked in vain in Mr. Dar^vin's works to find any 

 such acknowledgment, and I think Mr. Romanes has not 

 sufficiently distinguished between " useless characters " and 

 "useless specific distinctions." On referring to all the passages 

 indicated by him I find that, in regard to specific characters, 

 IVIr. Darwin is very cautious in admitting inutility. His 

 most pronounced "admissions" on this question are the follow- 

 ing : " But when, from the nature of the organism and of 

 the conditions, modifications have been induced which are 



