INTRODUCTION 



The present paper is a study in one of the recent phases of 

 modern botany as applied to the nation's greatest commercial asset, 

 agriculture. The audience for which it is intended is a large one, 

 for the discussion is mainly directed toward farmers, albeit they 

 may be a special group of farmers. Some perchance are not ac- 

 quainted with the art of agriculture or the business side of it ; some 

 may never have lived on a farm ; while most of the members of this 

 group will be interested in the scientific aspects of plant life. The 

 last named constitute the special group who are to be reached by 

 the following series of investigations. For at this time more than 

 ever before in the world's history are the scientists looking in on 

 gatherings where business men meet. This predicates their appear- 

 ance at farmers' meetings. In the crowded places the man of sci- 

 ence learns the things most needful for human welfare. The "pure 

 scientist" who studies the fundamental principles and the "applied 

 scientist" who develops these principles can then work in harmony 

 for the betterment of civilization. The "pure botanist" and the 

 agriculturist, one of the many workers in different fields who draws 

 his fundamental facts from the botanist, can do team work with 

 benefit to each other and humanity. 



The purpose of the paper is to show the relation of ecology to 

 agriculture and to introduce ecology to agronomists. In order to 

 do this the general ecology of plants must be discussed first. For 

 the working principles of the ecologist have been derived from 

 studies of the native vegetation. There is much good work in this 

 field which may be taken over verbatim for the use of the practicing 

 agronomer. There is also a good deal which may be derived from 

 experimental and laboratory work. Whenever it has seemed possi- 

 ble to the author, the accumulated facts of agriculturists have also 

 been grouped so that they may be of use to the ecologist in widen- 

 ing his principles and working generalizations, for it is believed 

 that the mutual assistance to be derived from such cooperation may 

 in some cases prove to be a revelation to plant ecologists and agri- 

 culturists. 



A consistent and wilful attempt is made throughout the paper 

 to avoid the older, though still widely accepted, static ideas of the 



