74 EVOLUTION 



mentary canal into the blood-vessels, can be 

 completely described in terms of physical 

 formulae. The fact is that when we add up 

 the components revealed by chemical and 

 physical analysis, they do not amount to 

 the whole resultant which we see in a vital 

 action, even of a simple sort. 



It is indeed ^profitable to compare a living 

 creature to a machine, ancf a fertile method 

 of discovery to press this comparison to its 

 hardest. Yet t.]^ Jiving organism differs 

 from anv macljjne in its greater efficiency: 

 and especially in this, that, f-.frp transfer of 



into it is attended with effects con- 



to further transfer anrl 



^ ftf -^iffsipn-t.io n - Again in this, that it is a 

 vrV^ v self-stoking, self-repairing, self-preservative* 

 y /'-S-elf -ad justing, jj^lf-inrre^simg. self-rero- 

 ^ 



ducinff engine! And this also must be re- 

 membered in comparing a living creature 

 and a machine, that the latter is no ordinary 

 sample of the inorganic world. It is an 

 elaborated tool, ah extended hand, and has 

 inside of it a human thought. It is because 

 of these qualities that highly complex ma- 

 chines come to be so like organisms. But 

 QO machine profits by experi^nr*e 



with timers organisms dp. Therefore it is 

 that the formulae that serve to describe the 

 activity of a machine will not suffice for 



