482 DB. ALFRED B. WAXLACE ON 



time." We now know tliat variations of almost every conceivable 

 kind occur, in all the more abundant species, in every genera- 

 tion, and that the material for natural selection to work upon 

 is never wanting. Accepting, then, these facts of variation, and 

 always keeping in mind the severity of the struggle for existence, 

 nine tenths at least of the progeny of the higher animals perishing 

 annually before reaching maturity, thus leading to a systematic 

 and contiaual weeding out of the less fit — let us endeavour to 

 realize the process of the formation of new species and the 

 nature of the characters which distinguish allied species from 

 each other. 



In my article on " Mimicry and other Protective Eesemblances 

 among Animals," first published in 1867, I laid down the 

 principle of utility, perhaps a little too absolutely, in the following 

 passage :—" Perhaps no principle has ever been announced so 

 fertile in results as that which Mr. Darwin so earnestly impresses 

 upon us, and which is indeed a uecessary deduction from the 

 theory of Natural Selection, namely — that none of the definite 

 facts of organic nature, no special organ, no characteristic 

 form or marking, no peculiarities of instinct or of habit, no 

 relations between species or between groups of species, can 

 exist but which must now be or once have been useful to the 

 individuals or races which possess them." Professor Huxley, 

 in his obituary notice of Darwia, expressed the same idea as 

 follows : — " Every variety which is selected into a species is 

 favoured and preserved in cousequence of being, in some one 

 or more respects, better adapted to its surroundings than its 



rivals For, as has been pointed out, it is a necessary 



consequence of the theory of Selection that everj' species must 

 have some one or more structural or functional peculiarities, in 

 virtue of the advantage conferred by which it has fought through 

 the crowd of its competitors and achieved a certain duration. In 

 this sense it is true that every species has been ' originated by 

 selection.' " Now these characters, in virtue of which, the 

 variety has become a species, are in fact its "specific characters," 

 and they alone will absolutely differentiate it from all other 

 species. We need not trouble ourselv^es about the cases of 

 doubtful species, in which the distinctive characters are either so 

 minute or so unstable that we cannot invariably determine 

 them. On the theory of evolution by natural selection there 

 must be such cases. They are species in the making and not 



