304 



BIOLOGY OF THE PROTOZOA 



Fig. 153.— Uroleptus halseyi. Second and third meiotic divisions of the micro- 

 nucleus, approach of gametic nuclei, metaphase of first zygotic nuclear division 

 and second zygotic nuclear division. X 1750. (After Calkins, Arch. f. Protisten- 

 kunde, courtesy of G. Fischer.) 



