148 



BERTRAM G. SMITH 



D, 



SUMMARY 



The follicular layer proper of the ovarian egg of Crypt obranchus 

 is formed from some of the deeper non-germinal cells of the ova- 

 rian wall which resemble the epithelial cells of the outer and inner 

 limiting membranes. The follicular membrane proper completely 

 surrounds the egg and is suspended in a two-layered flask-shaped 

 sac which projects from the inner surface of the wall of the ovary 



p.s. II 



■rasz:.iyf-^'<i<Mi^'JiP^ 



51 



•pj:^:r,;l.'.-(i,!.,^J-i;i.jA.i',:rrj 





;i«v,fe\^i'iS&S;-,,aiiKj--,V»(VS'*^ 



52 



Fig. 51 Meridional section through an egg of Cryptobranchus allegheniensis, 

 killed If hours after fertilization, showing the condition of the blastodisc. The 

 irregular faintly stippled areas near the animal pole contain yolk-free cytoplasm. 

 X 18. p. s. //, second polar spindle. 



Fig. 52 Meridional section through an egg of Cryptobranchus allegheniensis, 

 killed 12 hours after fertilization, showing condition of the blastodisc and position 

 of the copulation-nucleus. Yolk-free cytoplasm is segregated in a broken layer 

 near the surface of the blastodisc. The copulation-nucleus is shown a little to the 

 left of the center of the figure. X 18. 



