PREFACE 



IN this second edition I have followed the advice 

 of the reviewer of the first edition in " The Week's 

 Survey " and, abandoning the shackles imposed by 

 publishing a series of separate essays, each calculated 

 to take rather more than an hour to read, have 

 completely re-arranged the work, and have added 

 to it considerably, so as to make it practically a new 

 book. And I hope that these additions have 

 strengthened the argument. 



For many years I was content to hold Darwin's 

 position of recognising the variations of animals and 

 plants as facts, the origin of which it was hopeless 

 to try to explain. But lately I have again studied the 

 question, and found, in Professor Ewald Bering's 

 well known essay on Memory, the germ of a theory 

 which simplifies everything, and throws quite a new 

 light on definite variation. In fact, it reduces our 

 difficulties nearly to one the everlasting mystery of 

 the nature of mind ; a difficulty which can never be 

 solved. So I have explained this theory more fully, 

 and have tried to substantiate it. This has led me 



