INTRODUCTION 299 



things and others like them, we may be able to be of decided 

 help to the plant ; and furthermore, we may be able to help 

 the soil without abusing it, to use it without diminishing its 

 usefulness. 



It is obvious, therefore, that in the following pages we must 

 consider the structure and role and manipulation of the soil 

 so far as plants are concerned, as well as the needs of our 

 cultivated plants and how to meet them. 



