THE MOVEMENTS AND HABITS OF PLANTS. 23 



acquired through each part occasionally varying in a 

 slight degree but in many "ways, with the preservation of 

 those variations "which "were beneficial to the organism 

 under complex and ever-varying conditions of life, tran- 

 scend in an incomparable manner the contrivances and 

 adaptations "which the most fertile imagination of man 

 could invent. 



The use of each trifling detail of structure is far from 

 a barren search to those who believe in natural selection. 

 "When a naturalist casually takes up the study of an or- 

 ganic being, and does not investigate its whole life (im- 

 perfect though that study will ever be), he naturally 

 doubts whether each trifling point can be of any use, or, 

 indeed, whether it be due to any general law. Some 

 naturalists believe that numberless structures have been 

 created for the sake of mere variety and beauty — much 

 as a workman would make different patterns. I, for 

 one, have often and often doubted whether this or that 

 detail of structure in many of the Orchidem and other 

 plants could be of any service ; yet, if of no good, these 

 structures could not have been modeled by the natural 

 preservation of useful variations ; such details can only 

 be vaguely accounted for by the direct action of the con- 

 ditions of life, or the mysterious laws of correlated growth. 

 Fertilization This treatise affords me also an opportunity 

 of Orchids, f attempting to show that the study of or- 

 ganic beings may be as interesting to an ob- 

 server who is fully convinced that the structure of each 

 is due to secondary laws as to one who views every trifling 

 detail of structure as the result of the direct interposition 

 of the Creator. 



