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BERTRAM G. SMITH 



in the disappearance of the vitelUne bodies are not closely asso- 

 ciated with the formation of yolk granules, nor have I found any 

 undoubted 'yolk nuclei/ such as have been described by King 

 ('08) for Bufo. In view of the diversity in the methods of yolk- 

 formation described for different amphibians, this result is not 

 altogether surprising. 



Fig. 21 Section through an ovocyte and ovarian wall of a 35 cm. Cryptobran- 

 chus allegheniensis, showing the follicle and the distribution of nucleoli. In this 

 ovocyte the vitelline bodies have disappeared, but yolk-formation has not yet 

 begun. X 60. n., nucleolus. 



In the more advanced ovocytes of a 35 cm. female (see fig. 21). 

 the nucleoli stain deeply with borax carmine used after Zenker's 

 fluid. There is usually a marked concentration of the nucleoli 

 on the side of the germinal vesicle toward the periphery of the 

 ovary. Account must be taken of the fact that shrinkage of 

 the germinal vesicle also proceeds, as a rule, most extensively 

 on this side, leaving a large space, while the opposite side remains 

 in contact with the cytoplasm. This greater shrinkage on the 



