172 TORREY 



TEXT-FIGURE i. 



A, 2-cell stage from above; B, 4-cell stage from above, /^., polar globules; 

 C, 8-cell stage from above ; D, 8-cell stage from the side ; -£",16, forming 24 cells ; 

 F, 24, forming 32 cells, division of second quartet and primary trochoblasts. The 

 boundaries of the four quadrants, D, posterior ; A and C, lateral ; and B, an- 

 terior ; are indicated by heavy lines. 



