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 zz 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 
