284 THE SALAMANDER 



He however made the mistake of imagining that in both the male 

 and the female the ureters entered Miiller's duct some distance 

 anterior to the cloaca. Spengel and Schneider in the year 1876 de- 

 monstrated independently that the two ducts remain quite distinct 

 throughout their course, and enter the cloaca by separate orifices. 

 The former author made a careful study of the Miillerian duct 

 in the male, and found that it was traceable, by means of sections, 

 the whole way along the ventral side of the urino-genital duct to the 

 cloaca, where it ended blindly. It normally extends forwards to the 

 point on the posterior wall of the 'diaphragm', where the ostium 

 tubae is situated in the female. It is bound up in a common connec- 

 tive tissue capsule with the urino-genital duct so as to be indistin- 

 guishable from it except in sections. It is noteworthy that Miiller's 

 duct, and its associated urino-genital duct in the male, are always 

 pigmented, while they never are in the female. The ureters may also 

 bear pigment in the male, but it is usually absent or only very slight. 

 There are no vesiculae seminales. 



2. The Testes. 



The testes (tes.) are paired and somewhat asymmetrically placed 

 in the abdomen, the right side being slightly anterior to the left. 

 They are suspended by the mesorchia from the mesial edges of 

 the 'sexual kidneys'. Each testis consists of one, two, or three main 

 lobes (usually two), and each lobe is further subdivided by constric- 

 tions into two or three zones of different texture and colour, depend- 

 ing on the state of development attained by the sperms within. The 

 lobes of the testis are connected by a narrow strand of genital tissue, 

 while a flagelliform projection of a similar nature extends anteriorly 

 and posteriorly from the corresponding terminal lobes. Meves (1896), 

 as the result of a cytological investigation, distinguishes the following 

 zones in a testis lobe during July or August, i.e. when fully 'ripe'. 



(i) The anterior (or posterior) 'flagellum' and the connecting 

 strand, greyish in colour, containing spermatogonia embedded in 

 connective tissue. 



(ii) The anterior zone — forming the bulk of the lobe — also grey, 

 containing spermatocytes, and 



(iii) a more opaque zone (or sometimes two zones), yellowish or 

 whitish in colour, lying immediately posterior to the spermatocyte 

 zone, containing ripe sperms. 



More recently (1922) Humphrey investigated the seasonal de- 

 velopment of the testis in an American Urodele and obtained some 

 interesting results which may well be recapitulated here, since they 



