160 PLANT LIFE 



conceivable device which has not been actually 

 put into practice by one or another of them. 

 But whatever be the particular nature of 

 the adaption in any given instance, its final 

 significance, and its ultimate justification, is 

 to be sought in the assistance it renders towards 

 the proper discharge of the photosynthetic 

 functions of the green surface. 



Plants which contain no chlorophyll and 

 there are vast numbers of them have no 

 use for the varied complications that circum- 

 stances may render essential or ancillary to 

 the green members of the vegetable kingdom. 

 Indeed, it is not too much to say that all the 

 beauty of form, all the elaborate structure, 

 which is so copiously displayed by the vegeta- 

 tive organs of trees and plants generally, 

 spring from the possession of this substance 

 chlorophyll, with its wonderful power of 

 trapping and utilising the energy of the 

 sunlight. 



But apart from all aesthetic considerations, 

 and regarding the matter solely from the 

 most material point of view, we may further 

 assert that the elaboration of chlorophyll 

 has been fraught with consequences to the 

 whole organic world compared with which 

 all the other structural products of evolu- 

 tionary change sink into insignificance and 

 obscurity. 



