MATURATION OF GAMETES 



139 



latter process is called "terminalization." Coincident with this partial separa- 

 tion, a further contraction of the tetrads may occur. As a result, at the end 

 of diakinesis the tetrads may assume such curious shapes as loops, crosses, 

 rings, etc., scattered within the nucleus of the female and male meiocyte (fig. 

 69, diakinesis). The nuclear membrane eventually undergoes dissolution, and 



MITOCHONDRIA 



MATERIAL 



E R M HEAD 



REMNANT 



Fig. 73. Various aspects of Sertoli-cell conditions in the fowl. (Redrawn from Zlotnick, 

 Quart. J. Micr. Sc, 88.) (A) Resting Sertoli cell, showing mitochondria. (B) Sertoli 

 element at the beginning of cytoplasmic elongation. (C) Sertoli cell with associated 

 late spermatids. 



