14 THE CANADIAN NATURALIST. [Vol. 



VI, 



rest, man has produced very strongly marked varieties, whicli 

 continue "permanent " so long as this care is given, but which, 

 the instant it is relaxed and a free crossins; with other breeds is 

 allowed, show that they are only varieties and not true species by 

 reverting to the original stock. It may also be admitted that in 

 nature a somewhat similar selection takes place, especially under 

 the form of " sexual selection," but there is as yet no evidence 

 whatever that natural species can be compared to the breeds of 

 domesticated animals ; and to ascribe to "selection " of any kind 

 the power of originating species merely because it can preserve 

 useful individual varieties^ is as illogical as — if so homely a simile 

 is allowable — to suppose that the man who is able to manage his 

 own house is, therefore, competent to "keep a hotel." Natural 

 selection may be a true cause, but it is not shown to be a sufficient 

 cause. 



It may here be noted that reversion is not mentioned in any of 

 the statements of the theory of natural selection by either Dar- 

 win or Wallace. Yet the former treats of the subject at length, 

 and even depends upon its agency, after the lapse of thousands of 

 years, to account for the sudden reappearance of otherwise inex- 

 plicable structures ; so that, if we give to reversion the weight 

 which Darwin himself allows it when it favours his views, his ar- 

 guments against its action (pages 28 and 160) do not remove 

 what is really a very serious objection to the theory of natural 

 selection as applied to the production of specific forms in nature. 



This whole subject is well presented by Mivart in the chapter 

 on "Specific Stability;" and we have alluded to it here because 

 it has always seemed to us to involve a fundamental fallacy which 

 the author of "Natural Selection" is bound to remove. 



The object of the "Genesis of Species" is "to maintain the 

 position that natural selection acts, and, indeed, must act; but 

 that still, in order that we may be able to account for the pro- 

 duction of known kinds of animals and plants, it requires to be 

 supplemented by the action of some other natural law or laws, as 

 yet undiscovered" (page 5). This is, we may remark, but one 

 of the numerous evidences that, while the general theory of 

 "derivation" has been steadily gaining adherents even from 

 among its original opponents, yet "natural selection" — Darwin- 

 ism " pure and simple" — has been, and is still, losing ground even 

 with those who were inclined to adopt it. Huxley " adopts it 



