THE MULTIPLE TESTIS IN URODELES. 



R. R. HUMPHREY, 



DEPARTMENT OF HISTOLOGY AND EMBRYOLOGY, CORNELL UNIVERSITY, 



ITHACA, NEW YORK. 



In a recent paper (" The Interstitial Cells of the Urodele Testis," 

 1921) the writer referred briefly to the occurrence, in various 

 urodeles, of what might be termed a multiple testis a testis made 

 up of a series of enlargements, each of which is morphologically 

 and functionally similar to the others or to the simple testis found 

 in the majority of American urodeles. Successive enlargements 

 are separated by constricted regions, often of greater length than 

 the enlargements themselves. Such regions have been referred to 

 by investigators as " sterile." This designation, however, is clearly 

 inapplicable, since, as we shall see, reproductive cells are not absent. 



Of the twelve species of American urodeles examined by the 

 writer, multiple testes are found to occur in three Dcsmognathus 

 fusca, Dicmyctylus viridcsccns, and Diemyctylus torosus. 1 Among 

 the urodeles of Europe, according to Champy, axolotl and the 

 tritons exhibit this feature. I myself have examined testes of the 

 European Salamandra atra and find them to consist of as many as 

 three enlargements or lobes. 2 



Though the multiple testis is of rather common occurrence, no 

 satisfactory discussion of its origin and significance has yet been 

 encountered in the literature. Following are a few of the most 



i von Wittich ('53) describes and illustrates (his Fig. 18) the testis of 

 Neclurus lateralis (Nectnnts inaculosa) as consisting of three parts or lobes. 

 Hoffmann ('73-78} in Bronn's " Klassen und Ordnungen der Amphibien ", 

 states that von Wittich also describes the testis of Menopoma (Cryptobrancluis 

 allegheniensis) as of the multiple type. The author has found in Necturus 

 no testes such as that illustrated by von Wittich, though about sixty males 

 have been examined; neither has a multiple testis been found in any of the 

 six Cryptobranchus males studied. 



- Each enlargement or secondary testis will in this discussion be termed 

 a lobe, a designation agreeing with that employed by Champy and other 

 workers. 



45 



