220 THE NATURE AND ORIGIN OF LIFE 



the ultimate sexual elements are smaller than cells ; proto- 

 plasm is made up of particles, concerning the nature of \vhich 

 we make no hypothesis, but they have the two sexes. The 

 two poles of these particles must coexist in the act of assimila- 

 tion : assimilation is a bipolar phenomenon. 



Here we have a result of prime importance with relation 

 to the nature of vital phenomena. 



Sex does not manifest itself to us in a manner easy to 

 follow optically, except in the case where the phenomenon 

 of sexual maturation (still unknown to us in its essence) 

 reaches entirely the complete cellular elements so as to make 

 of them sexual elements. In this case, in fact, we verify 

 that there is cellular sex properly so-called a cellular sex 

 resulting, as we have just seen, from the total disappearance 

 of one of the intracellular sexes in each of the intraproto- 

 plasmic bipolar elements. 



Thus, even in sexual phenomena, the ultimate element is 

 not the cell, but is smaller than the cell. We came to this 

 same conclusion for all ultimate elements of elementary life 

 when we studied the Lamarckian or auto-adaptive variations 

 of unicellular beings. On this account it is irrational to 

 divide up a being into cells in the study of heredity as we 

 have seen Darwin and Weismann doing. 



Two phenomena, as general as they are mysterious, 

 throw singular light on this notion of intraprotoplasmic 

 bipolarity. They are alternating generation and karyokinesis. 



