68 GERM-CELL CYCLE IN ANIMALS 
preceding generation or to that contained in all of 
the sixty-four odgonia which descended from that 
primordial germ cell. That is, the pole-plasm of 
the odcyte under discussion has in some way increased 
until its mass is sixty-four times as great as that of 
the odgonium before the growth period began. How 
this increase has taken place can only be conjectured. 
The pole-plasm in the o6gonium may have produced 
new material of its own kind either by the division 
of its constituent particles or by the influence of its 
presence. In any case a localization of this substance 
occurs at the posterior end of the egg just before 
maturation. Therefore, although we can follow the 
germ cells in Miastor throughout their entire cycle 
without difficulty, there are certain problems, such 
as the history of the pole-plasm during the growth 
period of the odcytes, which still remain unsolved. 
