CHAPTER XXI 

 NATURAL SELECTION 



THERE is one capital difference between the two methods 

 as we have explained them. 



In the first we consider assimilation pure and simple as an 

 approximate law, on account of different variations due to 

 any destructive actions whatsoever and superposing them- 

 selves in any manner whatsoever on the results of assimila- 

 tion taken strictly. 



In the second, on the contrary, we do not separate the 

 assimilation from the variation ; we verify a result as a 

 whole, a synthesis comprising the whole activity of the living 

 body under the influence of all the surrounding circum- 

 stances considered together. We also verify that results 

 thus obtained are subject to the law of functional assimila- 

 tion, the immediate result of which is the adaptation of 

 organisms to the environment. 



With the first method we consider individual A as multi- 

 plying in its own likeness and then undergoing superposed 

 variations, caused by the influence of the conditions of the 

 environment included in the term B. With the second 

 method we know nothing about the organism A in itself ; 

 but the organ A of this organism, as defined by the function 

 symbolically represented in the formula (A x B), multiplies 

 by functional assimilation as the organ so defined and conse- 



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