THE CELL AND PROTOPLASM. 



125 



but each of these two cells, the egg and the polar 

 body, receives four chromosomes (Fig. 38). The 

 result is that the egg has now the normal number 

 of chromosomes for the ordinary cells of the ani- 

 mal in question. But this is still too many, for 

 the egg is soon to unite with the male cell ; and 

 this male cell, as we shall see, is to bring in its 

 own quota of chromosomes. Hence the egg must 

 get rid of still more of its chromatin material. 



PC' 



FIG. 40. 



5. First division complete and first polar cell formed, pc'. 

 ). Formation of the second polar cell, 



FIG. 38. I 



FIG. 39. Formation of the second polar cell,pc" 



FIG. 40. Completion of the process of extrusion of the chromatic 

 material ; fn shows the two chromosomes retained in the egg 

 forming the female pronucleus. The centrosome has disappeared. 



Consequently, the first division is followed by 

 a second (Fig. 39), in which there is again pro- 

 duced a large and a small cell. This division, 

 like the first, occurs without any splitting of the 

 chromosomes, one half of the remaining chromo- 

 somes being ejected in this new cell, the second 

 polar cell (pc") leaving the larger cell, the egg, 



