Function of Polar Bodies. xxv 



first polar body, and, according to his later views, the 

 extrusion of both polar bodies is a provision for with- 

 drawing promiscuously certain ids of germ-plasm for 

 the purpose of securing variation. He says : 'I consider 

 this remarkable and apparently useless process of the 

 doubling and two subsequent halvings of the idants, as 

 a method of still further increasing the niimher of possible 

 combinations of idants in the germ-cell of one and the same 

 individual ' ' ; the three quarters of the mass of germ- 

 plasm which passes into the polar bodies, he regards as 

 being 'again lost'V while what is left in the ovum, after 

 being increased by one spermatozoon, is halved by the 

 first nuclear division ; one half going to direct ontogeny, 

 and the other half going to form the primary sexual 

 cells : but as these last divide and behave at first like 

 other somatic cells, they must, he thinks, possess active 

 idioplasm as well as unalterable germ-plasm, and they 

 must therefore contain more ids in their nuclear matter 

 than do somatic cells ''. 



I incline to the view that these cells in the C3^nipidae 

 remain somatic, and simply form the rudiments of the 

 sexual organs, but that the function of the polar bodies 

 is to provide the primitive reproductive cells. These 

 bodies contain the inactive germ-plasm, historically 

 prepared for this very purpose, and it is scarcely possible 

 to imagine that nature would create this phyloge- 

 netic epitome of the species to be extruded as func- 

 tionless, or to be broken up and again lost \ It is 

 undeniable that they are of great value in promoting 

 variation. The first division of the nucleus into two 

 oocytes is not a reducing division, but results, so far as 

 the germ-plasm is concerned, in two equivalent cells. 



^ Weismann, Germ-plasm, p. 247. - Ibid. p. 248. 



2 Ibid. p. 192. * Ibid. p. 248- 



