212 HISTORY OF BOTANY 



the work of those who followed him and who either 

 controverted or modified his conclusions, and that would 

 entail an expenditure of far more time than I can spare 

 in a summary as brief as the present. Besides, I shall 

 have to sketch out the modern position of the subject 

 later on in relation to the work of Willstatter and his 

 pupils, and it would therefore seem unnecessary to follow 

 in detail through the maze of controversial literature to 

 which I have referred. 



