PREFACE 



Emphasis is therefore placed on plant 

 growth and the operations which affect it most 

 directly. Special reference is made to the ob- 

 servation and study of the growth habits of 

 plants as the basis for making every effort 

 count. 



It is a pleasure to acknowledge here the 

 assistance of Professor Fred. C. Sears, who 

 read the manuscript, and of Professor Frank 

 A. Waugh, who edited it. Without the in- 

 spiration and kindly advice of these men the 

 book would never have been written. 



R. A. Van Meter. 

 Amherst, Mass. 



