INFLUENCE OF ENVIRONMENT ON PLANTS 351 



general habit serve to show us that there is, throughout 

 the vegetable kingdom, a constant effort on the part of the 

 plant to adapt itself to its surroundings, so as to make the 

 best of the external conditions. This struggle, though 

 perhaps most easily realised by a survey of large groups 

 which are affected, is really carried out by the individual 

 organisms, and the comparatively striking effects seen are 

 the result of the cumulative efforts of a long series of indi- 

 viduals, each of whom has possessed in different degrees 

 powers of reacting to varying external conditions. These 

 powers will be considered in subsequent chapters. 



