DEGENERATIONS, DESMOGNATHUS 243 



indicates possibly a rhythmic discharge of material from the nu- 

 cleus. The chromatin plate described by him likewise is indicative 

 of an idiosome-nuclear correlation. 



Practically nothing is known regarding the frequency of occur- 

 rence in amphibia other than Salamandra and Desmognathus, of 

 degenerations similar to those described. Through the kind- 

 ness of Dr. Montgomery sections of the testis of Plethodon cine- 

 reus erythronotus were examined and comparable degenerations 

 were found to be present. Likewise they have been seen in the 

 testis of Salamandra atra. In these forms, however, no system- 

 atic study of the degenerations has been made in which there has 

 been seriously attempted the ascertainment of any definite rela- 

 tion to the process of spermatogenesis, the stage at which they 

 occur, their relation to the annual cycle or their location within 

 the testis, nor has the relation of the spermatogenetic process to 

 the testis been studied. 



Miss King ('07) has found no trace of such degenerations in 

 Bufo. She says: ''I have never found a condensation of the 

 chromatin in the spermatogonia as Kingsbury has described for 

 Desmognathus, and I am unable to confirm his statement that 

 'contraction figures do not occur constantly in spermatocytes.'" 

 To this the following comments may be made; first, that work 

 upon one form cannot be relied on for confirmation or disproof of 

 work done upon another form. The spermatogenetic process 

 seems to be worked out in the anuran testis in a way quite dif- 

 ferent from that prevailing among the urodeles. In the toad it 

 is apparently intralobular; many different stages are found with- 

 in the confines of a single lobule.* The seriation of stages in such 

 a testis as the toad's are much more difficult, and, it may be ven- 

 tured, karyolytic nuclei might easily be overlooked as they would 

 probably occur singly. This, however, from Miss King's careful 



^ Cf. King, '07, p. 346. "As a rule all of the cells in a cyst are in approximately 

 the same stage of development, but a single follicle [lobule] may contain both 

 spermatogonia and maturing spermatids. A transverse section of the testis, 

 therefore, shows practically all stages in the development of the spermatozoa." 

 In Desmognathus in a transection all cells would be in approximately the same 

 stage, while in a single longitudinal section at the right season of the year, prac- 

 tically every stage might be seen. 



