B. F. Kingsbury 101 



His results did not sustain those of vom Eatli; no tetrad formation was 

 found to occur, and there were but three cell-generations instead of six. 

 On the other hand, the divisions of the spermatocytes he found to be 

 equation divisions, the first heterotypic in character, the second homo- 

 typic, not mixed as Flemming had thought; furthermore, the spermato- 

 cytes of the third generation did not divide as Flemming seems to have 

 supposed.' His paper, 97, dealt with the entire spermatogenesis, the 

 structure and divisions of the spermatogonia, as well as the growth and 

 divisions (two) of the spermatocyte, involving a consideration of reduc- 

 tion. The papers of McGregor and Eisen, which will be considered in 

 the body of this article, supported the results of Meves (as far as the 

 purposes of this paper are concerned). These five papers include the 

 more exhaustive investigations of Amphibian spermatogenesis. Minor 

 papers contributing to our knowledge but not dealing with the question 

 of reduction need not be considered here, as also the work of older 

 writers of historical interest in the analysis of the structure of the Am- 

 phibian testis. Of the publications on Amphibian oogenesis, the only 

 one that is of impoi-tance for the purposes of this article is the paper of 

 Carnoy and Lebrun. 



DESMOGNATHUS FUSCA. 



The form chosen for this investigation is one of the most abundant 

 salamanders in this locality (Ithaca, New York, U. S. A.), and in eastern 

 United States generally; it is likewise the most abimdant species of the 

 genus. In 1866 the Desmognathidce were recognized by Cope as a 

 distinct family, represented by a single genus, to which have since been 

 added the genera Thorius, Typhlotriton, and finally, Leurognathus. 



Desmognathus, in habits is semi-aquatic, living at the edge of swiftly 

 running brooks, especially near or at springs. It chooses concealment 

 under stones at the edge of the stream, or among the pebbles of coarse 

 gravel, saturated with water; dry ground, and also deep water in the 

 bed of the stream, it apparently avoids. If confined in an aquarium 

 of still water, it will crawl up the sides so that its head and a portion 

 of its body are out of water; if prevented from thus gaining access to 

 the air, it speedily dies. 



It is said to be nocturnal in its feeding habits. Wilder, 99, wandering 

 forth in search of its food, which consists of small insects (beetles, etc.) 

 and their larvae. 



Of its breeding habits and development very little is known. The 



3 See note 2, p. 100. 



