PREFACE 



THE object of this book is to prove that 

 Evolution so far as Plants are concerned 

 depends upon the Inheritance of Acquired 

 Characters. This was Darwin's contention. 

 Dr Weismann and his followers assert that no 

 such characters can ever be hereditary unless 

 the influence of the environment can reach and 

 affect the reproductive organs, or his hypo- 

 thetical substance "germ-plasm." As all the 

 characters of the vegetative system, or the soma 

 of plants, which are regarded as specific, are 

 acquired long before any reproductive organs 

 exist at all, and therefore before any vegetative 

 cell has begun to assume a reproductive character, 

 Dr Weismann's proviso is inappplicable to 

 plants. 



Present-day Ecologists who study plants in 

 nature, are all at one in accepting the fact 

 that evolution in plants is the result, not only 

 of a natural response to the direct action of 

 changed conditions of life, by means of which 



