vi VEGETABLE PHYSIOLOGY 



more fully than before the general relations of the in- 

 dividual and its environment. 



I have set myself throughout to combat an idea that 

 has arisen during the last few years that many changes 

 may go on in protoplasm without involving any inter- 

 change with its substance. This I hold to be erroneous. 

 In all the reactions of which it is the scene its own auto- 

 decomposition and reconstruction are involved. 



I have sought to keep the book within practically the 

 same dimensions as in former editions, and have conse- 

 quently compressed certain of the less important parts. 

 When introducing new matter I have tried to avoid undue 

 speculation as tending to confuse an elementary student. 



J. EEYNOLDS GBEEN. 

 CAMBRIDGE, May 1911. 



