86 Darwin, and after Darwin. 



cost — that the presence of a fully-formed shaking 

 reflex is of selective value in the struggle for exist- 

 ence, it is perfectly certain that all the stages 

 through which the construction of so elaborate a 

 mechanism must have passed could not have been, 

 under any circumstances, of any such value. 



But, it is needless to repeat, according to the 

 hypothesis of use-inheritance, there is no necessity 

 to suppose that these incipient reflex mechanisms 

 are of any value. If function produces structure in 

 the race as it does in the individual, the voluntary 

 and frequently repeated actions of scratching and 

 shaking may very well have led to an organic 

 integration of the neuro-muscular mechanisms con- 

 cerned. Their various parts having been always 

 co-ordinated for the performance of these actions by 

 the intelligence of innumerable dogs in the past, 

 their co-adapted activity in their now automatic 

 responses to appropriate stimuli presents no difficulty. 

 And the consideration that neither in their prospec- 

 tively more fully developed condition, nor, a fortiori, 

 in their present and all previous stages of evolution, 

 can these reflex mechanisms be regarded as present- 

 ing any selective — or even so much as any adaptive 

 — value, is neither more nor less than the theory of 

 use-inheritance would expect. 



Thus, with regard to the phenomena of reflex action 

 in general, all the facts are such as this theory requires, 

 while many of the facts are such as the theory of 

 natural selection alone cannot conceivably explain. 

 Indeed, it is scarcely too much to say, that most 

 of the facts are such as directly contradict the latter 

 theory in its application to them. \ But, be this 



