No. I.] SPERMATOGENESIS OF BATRACHOSEPS. 29 



somes that they cannot always be distinguished from them. In 

 the resting stages, however, the chromoplast or chromoplasts, as 

 there may be several, stand out quite distinctly and individual- 

 ized and can then be studied to the best advantage. This 

 refers not only to the resting stages of the polymorphous 

 nuclei, but also to those of the auxocytes, the spermatocytes, 



A polymorphous spermatogonium in the " perfect resting stage." The form of the nucleus allows 

 the most perfect metabolism. Numerous chromioles are connected by a thread of chromo- 

 plasm. A network of linosomes is partially indicated, the individual granules being con- 

 nected by linopodia. A large, oblong chromoplast with endochromatic granules. Eight 

 parachromatic granules. A single archosome in the cytoplasm, the latter only partially 

 indicated by small open circles. A single large, round linoplast, with seven endonucleolar 

 granules. 



and the spermatids. In the two first-named cells, which also 

 are the largest, they offer the best facilities for study. 



In the perfect resting stage of the polymorphous nucleus we 

 find always one, but sometimes two or more chromoplasts, 

 easily distinguished by their capacity for intense staining. 

 When the iron-haematoxylin-congo stain is used the chromo- 

 plasts become stained, as a rule, most intensely black, while 

 the true nucleoli, or linoplasts, take the congo and become 

 red. The chromoplasts are also characterized by possessing 



