THE DEGENERATIONS IN THE SECONDARY SPER- 

 MATOGONIA OF DESMOGNATHUS FUSCA 



B. F. KINGSBURY and PAULINE E. HIRSH 

 From the Histological Laboratory, Cornell University 



TWENTY-ONE FIGURES 



In 1902 there was published a part of the results of a study 

 of the spermatogenesis in Desmognathus fusca in which the 

 occurrence of degenerations^ in the secondary spermatogonia 

 was mentioned. A fire had destroyed the larger portion of the 

 preparations and photographs covering this portion of the sper- 

 matogenetic cycle, and no effort was then made to complete the 

 investigation by a detailed study of the spermatogonia. 



Of the degenerations that occurred two were particularly attrac- 

 tive — the regressive changes in the spent lobule and the degener- 

 ations in the last generation of spermatogonia, after the cessa- 

 tion of the season's transformation into spermatocytes. These 

 degenerations are described as occurring in spermatogonia of the 

 last generation, although they might quite as well, perhaps, as 

 will appear subsequently, be given as involving spermatocytes 

 at the very beginning of their growth period. 



The occurrence of degenerations in the amphibian spermato- 

 genesis has been known since the pioneer work of Flemming ('87) 

 on the spermatogenesis of Salamandra. He described (p. 447) 

 the vacuolation and fragmentation of the nucleus and the dis- 

 solution of the cell, constituting a form of degeneration already 

 described by him ('85). He says: 



Irgend eine Beziehung zur Spermatogenese kann diese Erscheinung 

 keinesfalls haben, da sie zu einer viel friiheren Zeit auftritt, als jene; 

 in den Praparaten von Hoden mit Spermatogenese, welche ich bisher 

 studiert habe, waren derartige Bilder nicht vorhanden, ich will jedoch 



« 



i Kingsbury, '02, p. 108, p. 111. 



231 



