Preface ix 



that if any one will undertake to question modern zoologists 

 and botanists concerning their relation to the Darwinian 

 theory, he will find that, while professing in a general way 

 to hold this theory, most biologists have many reservations 

 and doubts, which they either keep to themselves or, at any 

 rate, do not allow to interfere either with their teaching of 

 the Darwinian doctrine or with the applications that they 

 may make of it in their writings. The claim of the oppo- 

 nents of the theory that Darwinism has become a dogma 

 contains more truth than the nominal followers of this school 

 find pleasant to hear ; but let us not, therefore, too hastily 

 conclude that Darwin's theory is without value in relation 

 to one side of the problem of adaptation; for, while we can 

 profitably reject, as I believe, much of the theory of natural 

 selection, and more especially the idea that adaptations have 

 arisen because of their usefulness, yet the fact that living- 

 things must be adapted more or less well to their environ- 

 ment in order to remain in existence may, after all, account 

 for the widespread occurrence of adaptation in animals and 

 plants. It is this point of view that will be developed in 

 the following pages. 



I am fully aware of the danger in attempting to cover 

 so wide a field as that of " Evolution and Adaptation," and 

 I cannot hope to escape the criticism that is certain to be 

 directed against a specialist who ventures nowadays beyond 

 the immediate field of his own researches ; yet, in my own 

 defence, I may state that the whole point of view under- 

 lying the position here taken is the immediate outcome of 

 my work on regeneration. One of the general questions 

 that I have always kept before me in my study of regenera- 

 tive phenomena is how such a useful acquirement as the 

 power to replace lost parts has arisen, and whether the 

 Darwinian hypothesis is adequate to explain the result. 

 The conclusion that I have reached is that the theory is 

 entirely inadequate to account for the origin of the power 



