INTRODUCTION 113 



I recall one of the most striking illustrations of the data 

 collected in the chemical work which Miss Abbott accom- 

 plished in the arrangement of series of plants to illustrate the 

 development of certain particular compounds by genera and 

 species, and this arrangement of genera and species showed 

 in a most marked manner the development of the chemical 

 compounds forming important constituents of the plants ex- 

 hibited. 



The study of the principles of evolution during the last 

 fifty years has shown the dominating influence of environment 

 on the development of animals and plants. The investiga- 

 tions conducted by Miss Abbott also show the dominating 

 influence of environment upon the particular composition 

 of the plant. Thus were laid the first stones of the foun- 

 dation on which the important study of securing variations 

 in plants which change their environment is based. In the 

 careful breeding of plants there are two important things 

 which are to be kept in view. First, the development of new 

 forms or kinds of plants; and second, the development of a 

 more abundant content of valuable constituents of plants and 

 the elimination of the undesirable constituents. All of these 

 ideas were outlined in Miss Abbott's work, and from the 

 starting-point of these investigations most of the more im- 

 portant contributions to plant chemistry in this country in 

 relation to environment have been made. 



H. W. WILEY. 

 WASHINGTON, D. C., October ist, 1906. 



