1894. 



CELL-DIVISION. 



423 





• 'm 



\, Zone of 

 Germination. 



K I\ l\ i\ 



i 



• •• 



Ovocyte I. 

 Ovocyt-e. ir^ 



I \ ,,.., 



Ovccm . 



Zone of 

 TGrowth. 



Zone of 

 Maturation. 



2nd Polar Bodv 



Diagram Showing the Development of the Egg- 

 Cells IN AscARis MEGALOCEPHALA [ajtev Boven). 



Primitive Gerni-cell. 



Spermato 

 fortes 



'rmato- / \ 



• • • # 



/I /\/\ i\ 



Zone of 

 Germination. 



SpCfmatocyte I 



Spermatocyte M. 



Zone of 

 Growth. 



Zone of 

 Maturation. 



Spefmaii 



Spermatocyte 1= Sperm-grandmother-cell. 

 Spermatocyte II. = Sperm-mother-cell. 

 Spermatid = Spermatozoon. 



Diagram Showing the Development of the Sperm 

 Cells in Ascaris megalocephala [after Boveri). 



