GERM CELLS IN NEMATODES, SAGITTA 175 



somes intact. A similar reduction in the amount of 

 chromatin takes place in the fourth and fifth divi- 

 sions and then ceases. The single cell in the 32-cell 

 stage which contains the full amount of chromatin 



FIG. 51. Ascaris. Stages in early cleavage showing the chromatin- 

 diminution process in all cells except the stem cell (S). (From 

 Boveri, 1892.) 



has a larger nucleus than the other thirty-one cells 

 and gives rise to all of the germ cells, whereas the 

 other cells are for the production of somatic cells 

 only. The cell lineage of Ascaris is shown in the 

 accompanying diagram (Fig. 52). 



