Bancboft. — Distaplia occideutalls. 



PLATE 6. 



Fig. 47. Part of the wall of a corpus luteum from which the ovum has just passed 



out. 

 Fig. 48. Germinative vesicle just as it is beginning to shrink. From the same 



ovum as that in Fig. 28, measuring 173 X 150 /x. Reichert -^^ immers., 



Zeiss 2 ; X 890. 

 Fig. 49. Germinative vesicle and yolk-clump in an ovum of 190 n diameter. 



Reichert j^ immers., Zeiss 2 ; X 890. 

 Fig. 50. Germinative vesicle and central yolk bodies at a later stage. Ovum is 



254 fx in diameter. Zeiss -^^ immers., 2 ; X 1300. 

 Figs. 51-59. Nucleoli in various stages of development. Tlie measurements are 

 in (ji. 



Fig. 51. 

 Fig. 52. 

 Fig. 58. 

 Fig. 54. 

 Fig. 55. 

 Fig. 56. 

 Fig. 57. 

 Fig. 58. 

 Fig. 59. 



Figs. 60, 61. Two successive sections through the group of tetrads formed just 

 before the formation of the first polar cell. The ovum has just 

 reached the pouch. 



