42 A GREAT CONFESSION CHAP. 



mobilities of their ultimate constituents 

 that the waste products of vital activity 

 escape as fast as they are formed." : 

 Now, what is the value of sentences 

 such as this ? As an explanation, or 

 anything approaching to an explanation, 

 of the wondrous alchemies of organic 

 life, and especially of the digestive pro- 

 cesses of the appropriation, assimila- 

 tion, and elimination of external matter 

 this sentence is poor and thin indeed. 

 But whatever strength it has is entirely 

 due to its recognition of the fact that not 

 only the organism as a whole, but the 

 very materials of which it is "built up," 

 are all essentially adaptations which are 

 in the nature of " purposes," being indeed 

 contrivances of the most complicated 

 kinds for the discharge of functions of a 

 very special character. 



What, then, is the great reform which 



1 Principles of Biology, vol. i. p. 24. 



