FACTS 



197 



the body which acts, and that of morphogenesis or fabrica- 

 tion of the successive forms of the individual. The morpho- 

 biological theorem, as we have established it, prevents 

 these two points of view from being separable. There is 

 indeed a relation of cause and effect between the fabrication 

 of living substance and the corresponding construction of 

 individual forms. Reciprocally, since the form of the indi- 

 vidual at the point of its existence A n is an evident element 

 in determining the functioning (AJ x BJ, the law of 

 functional assimilation proves that the assimilation produced 

 in the body A n is not independent of the form of this body 

 considered as a mechanism. 



What has already been said of functional assimilation 

 in cases where the division of physiological labour produces 

 cellular differentiation dispenses us from further develop- 

 ing this subject. 



The really important question relative to the individual 

 evolution of living beings is to know how far, when the 

 heredity of the being is known, we can foresee what its 

 evolution is to be. Indeed, that which determines A M is 

 not only A 1? but also the whole educative series, B l5 B 2 , 

 B 3 . . . B M _ !. Now, while we are] acquainted with A 1} 

 we do not know a single term of the series B. Strictly 

 speaking, therefore, we are obliged to think that it will be 

 impossible for us to foresee anything at all relatively to A n . 



Sera-t-il Dieu, table ou cuvette ? 



We do not know. The larva which we see may be eaten 

 by a bird, crushed by a stone, transformed into a mummy 

 in formic aldehyde. There are any number of " Perhapses," 

 among which we are unable to choose beforehand. 



But not all these cases concern the biologist. The pro- 

 blem of individual evolution does not consist in foreseeing 

 what a living being will become under any and every con- 



