SPERMATOGENESIS 



Since in the testis tetrads occur only in the primary spermatocytes, 

 the cells shown in Fig. 20, G-J, are easily identified. These are success- 



F 



FIG. 30. SPERMATOGENESIS IN Dissosleira Carolina A-FXI4SO; G-LX966. (Davis.) 



A, B, C, prophase. metaphase. and telophase of a spennatogonial division. D-L, successive stages in the 



.division of a primary spermatocyte into secondary spermatocytes. 



ive stages in the division of the primary spermatocyte. In G the accessory 

 chromosome is seen as a rod-shaped body above and to the right; in H it is 

 below and to the right. In J it is obliquely placed just above the equatorial 



