CENTROSPHERE 



CENTROSOME WITH 

 DIPLOID CENTRIOLE 



MITOCHONDRIA 



YOLK NUCLEUS 

 OF BALBIANI 



Fig. 86. Young oogonia of the fowl entering the growth (oocyte) stage. (A) Idio- 

 some from which the Golgi substance has been removed and stained to show the cen- 

 trosphere (archoplasm). The centrosome has two centrioles. (B) Idiosome with sur- 

 rounding Golgi substance. The mitochondria surround the Golgi substance and the 

 nucleus. (After Brambell, '25.) 



/ NUCLEUS 



MITOCHONDRIAL CLOUD 

 GOLGI I" 

 MITOCHONDRIAL YOLK BODY 

 VACUOLE 

 GOLG I GRANULES 



Fig. 87. The so-called mitochondrial yolk body in the developing egg of the fowl. 

 (A) Oocyte from 11-week-old chick, showing mitochondrial cloud and Golgi substances 

 1 and II. (B) Oocyte from ovary of adult fowl, showing both types of Golgi substance 

 and mitochondrial cloud. (C) Oocyte from ovary of adult fowl, showing the appearance 

 of the mitochondrial yolk body within the mitochondrial cloud. (D) Oocyte from 

 ovary of adult fowl, showing fragmentation of Golgi substance I and the association of 

 the resulting Golgi granules around the mitochondrial yolk body. (After Brambell, '25.) 



155 



