THE SPEEMATOGENESIS OF DESMOGNATHUS FUSCA. 



B. F. KINGSBURY, Ph. D. 



Aissista7it Professor of Histology and Embryology^ Cornell University. 



With 4 Plates. 



The work of which this paper is the outcome, was undertaken in 

 the winter of 1896. Necturus maculatus was the form first chosen, but 

 it was soon abandoned for the salamander Desmognathus fusca, which 

 from its abundance, availability at all seasons of the year, and the 

 size and structure of its testis, seemed a more suitable object for the 

 work in hand. A preliminary note on the divisions of the spermatocyte 

 was published in 1899. In November, 1900, the drawings, photographs 

 and the larger portion of the preparations covering what would have 

 been the first part of this article were destroyed by the burning of the 

 histological laboratory of Cornell University. The plates (published 

 herewith) and the portion of manuscript discussing the divisions of 

 the spermatocyte were saved, and it has seemed best to publish that 

 portion without waiting to repeat the work of the first part, which would 

 take several years.' 



When this investigation waf- begun, the need for careful work on the 

 spermatogenesis of Ampjiibia was quite apparent. Eesearch on the 

 spermatogenesis of Amphibia had been largely confined to the European 

 salamander, Salamandra maculosa, and to that form alone had a mono- 

 graphic treatment been accorded, in the papers of Flemming, 87, vom 

 Rath, 93, and Meves, though his final paper did not appear until 1897. 

 Since this work was undertaken, however, McGregor, 99, has published 

 a monograph on the spermatogenesis of Amphiuma, and Eisen, 00, has 

 brought out an extensive article on Batrachoseps, another American 

 salamander. 



The results of Flemming and vom Rath have been reviewed by Meves, 

 97, and need not be discussed here in any detail. Flemming's paper, 



1 The writer wishes to acknowledge gratefully the help which has been given him 

 with the manuscript and preparations by S. H. Gage, head professor of the depart- 

 ment, and by M. Hempstead and C. F. Flocken, students in the laboratory. 



