THE P.EDOGENETIC FLY, MIASTOR 53 



gradually becoming reduced as the oocytes increase in 

 size. Finally the oocyte (and accompanying nurse 

 cells), still surrounded by the follicular epithelium, 



Fig, 12. — Miastor americana. Longitudinal section through an ovary. 



en = envelop; /.fp = follicular epithelium; n.c = nurse chanihcr; 



n.c.n = nurse-cell nucleus; o.m = mesoderm; ouc.ti = o(')cyte nucleus. 

 Fig. 13. — Miastor americana. Longitudinal section through a nearly 



full-grown oocyte, g.v = germinal vesicle; n.c = nurse chamlMT; 



pPl = pole-plasm. 



