Introduction 165 



its last fe\v years, being in a great degree the outcome of 

 the two lines of research which have just been mentioned. 

 The study of the relations between the environment and 

 the structure of the plant had given rise to the conception 

 of a physiological anatomy, and the development of physio- 

 logical adaptations had been found to be to a certain 

 extent an indication of relationship or affinity. The study 

 of such relationships in the light of physiological need, and 

 the consequent development of anatomical peculiarities 

 running through groups of plants, led to the recognition of 

 a new branch of botanical research, which became known 

 as Oecology. It was not limited, however, to these features, 

 but embraced the study of plant associations and the 

 relative influence of such forms to one another as well as 

 to the general conditions of their environment. This move- 

 ment, however, was in its infancy at the end of the century. 



