FACTS 



227 



asters. They form a true case of intracellular sexuality. 

 The centrosome is a sexual element which, we know not why, 

 has undergone sexual maturation in one direction, while the 

 cytoplasmic substances have undergone maturation in an 

 opposite direction. The asters are the image of a true intra- 

 protoplasmic fecundation. 



The movement of the centrosomes to the surface of the 

 nucleus (Fig. 20, from state A to state C) is especially 

 interesting and demonstrative of the attractions figured by 

 the asters. It is possible that the two centrosomes, which 

 have the same name, repel each other ; but if we attend to 

 the maturation in contrary directions of the cytoplasm as a 

 whole, it is evident that the resultant attractions must finally, 

 with the nucleus as a screen, bring the two centrosomes to 

 positions diametrically opposed with relation to the nucleus. 

 (Fig. 21, representing the movement of centrosomes around 

 the nucleus, offers a diagram of these attractions and 

 the resultant movement.) 



Karyokinesis is thus a new proof of intraprotoplasmic 

 bipolarity, or sexuality. It is a result of incomplete matura- 

 tion, or rather of two maturations in contrary directions 

 which, localized in the same cell, are able to correct each 

 other. On the contrary, when maturation in a given direction 

 takes possession of the whole cell, it gives a genital element 

 which can no longer be completed except by an element that 

 has matured in a contrary direction : these are cases of 

 total cellular sexuality studied two chapters back. 



The study of the phenomena of partial or total sexuality 

 has increased our knowledge of the nature of life by a new and 

 very important concept the bipolarity of the elementary 

 vital phenomenon. We have now to see the consequences 

 of sexual reproduction in questions of heredity. 



