BY JAS. P. HILL. 02( 



unexpected occurrence of the direct median passage in Dasyurus 

 impressed on me the necessity of testing the above assumption 

 by the examination of serial sections of the median vaginal 

 apparatus in Trichosurus, with the result that a pseudo-vaginal 

 passage was also found to occur in this form. 



The female genital organs of Trichosurus were described and 

 figured by Brass* in 1880, and in the following year W. A. 

 Forbes,! in a paper on the Koala, very shortly, in a footnote, 

 refers to the uteri and median vaginal apparatus without 

 alluding to Brass's account. 



According to the latter author, the uteri open "in die, von 

 Vaginae gebildeten, colossalen Blindsacke. Dieselben sind in 

 der Mittellinie vollstdndig durch ein Septum von einander yeschie- 

 den und bis hinab zum Sinus urogenitalis verlangert ohne jedoch 

 in denselben einzumiinden " (p. 13. Italics mine). His fig. 1 of 

 Taf. ii., representing the organs from the dorsal side, shows the 

 median vaginal apparatus ending abruptly in contact with the 

 approximated posterior portions of the lateral vaginal canals, 

 while his fig. 2, representing a horizontal section, shows the same 

 part terminating freely behind and unconnected in any way with 

 the lateral canals. I would again point out that such repre- 

 sentations of the relations of these parts are wholly inaccurate. 

 The posterior section of the median vaginal apparatus of Tricho- 

 surus passes down to enter, and lies imbedded in, the connective 

 tissue, which also encloses the posterior portions of the lateral 

 vagina? and the urethra. 



According to Forbes, "each os tincee projects as a prominent 

 and quite free papilla into the common vayinal chamber, formed 

 by the coalescence and fusion of the two diverticula present in 

 Phascolomys and Phascolarctos. This chamber is capacious and 

 has only a very slight indication of a median partition left " 

 (p. 190. Italics mine). 



* Brass, A. " Beitrage zur Kenntniss des weibliehen Urogenitalsystems 

 der Marsupialen." Inaug. Diss. Leipzig, 1880. 



t -Loc. cit. (ante), p. 190. Footnote. 



