THE CELL AND PROTOPLASM. 105 



growth the chromatin splits in such a way that 

 the egg contains double the number of chromo- 

 somes, i. e., eight (Fig. 34). If this egg should 

 now unite with the other reproductive cell from 

 the male, the resulting fertilized egg would plain- 

 ly contain a number of chromosomes larger than 

 that normal for this species of animal. As a re- 

 sult the next generation would have a larger num- 

 ber of chromosomes in each cell than the last 

 generation, since the division of the egg in devel- 

 opment is like that already described, and always 

 results in producing new cells with the same 

 number of chromosomes as the starting cell. 

 Hence, if the number of chromosomes in the next 

 generation is to be kept equal to that in the last 



FIG. 36. FIG. 37. 



FIG. 36. The egg centrosomes have changed their position. The 



male cell with its centrosome remains inactive until the stage 



represented in Fig. 42. 

 FJG. 37. Beginning of the first division for removing superfluous 



chromosomes. 



generation, this egg cell must get rid of a part of 

 its chromatin material. This is done by a process 

 shown in Fig. 35. The centrosome divides as in 

 ordinary cell division (Fig. 35), and after rota- 

 ting on its axis it approaches the surface of the 



