120 



NOTES ON MARSUPIALIAN ANATOMY. 



1. ON THE CONDITION OF THE MEDIAN VAGINAL. 



SEPTUM IN THE TRICHOSURID^. 



PI. XXI. 



By T. TlioinsMi) Flyim, B.Sc 

 Professor of Biology, University of Tasnuiuia. 



(Read October 9. 1911.) 



There has been at various times some little discussion 

 on the state of the median vaginal septum in vai'ioiis 

 members of the genus Trichosurus ; up to the present how- 

 ever, tlie only member of the group which seems to have 

 been examined is the common phalanger Trichosurus vul- 

 pecula. Brass (1) in 1880 described the organs of this 

 animal, and in his specimen found the two median cul-de- 

 sacs separated from one another by a complete partition. 

 In 1899 Forbes {'2), in a foot note on a communication on 

 the anatomy of the Koala, speaks of the median vaginal 

 apparatus as a "common vaginal chamber formed bv the 

 coalescence and fusion of the two diverticula present in 

 Phascolomys and Phascolarctos." 



In 1900 the question was finallv decided for T. vul- 

 jiecula by Hill (3), who, as a result of his own obsei'vations 

 on the genital organs of both virgin animals and those 

 which had given birth to young, conclusively showed that 

 in the former the septum was complete, in tlie latter it 

 was incomplete, causing a more or less complete coalescence 

 of the two cul-de-sacs, and that this condition of incom- 

 pleteness of the septum arose almost certainly as a result of 

 and most probably during the first act of parturition. Undea* 

 these circumstances, the incomplete nature of the septum in 



1. Brass A. " Beitriine ziir Keiiiitniss ties wi'ibliclien Urogenital .systeius der 

 Marsupialen." Leip/.ig, ISbO. 



2. Forlu's, W.A. "On some points in the Anatomy of the Koala (Fha.sco' 

 larctos finerens)." I'.Z.S., 18S1. 



3. Hill, .I.P. " Contrilmtions to the Morph. and Dev. of the IVm. Urog. 

 Organs in the Marsupials." J.) P.L.S., N.S.W., ISOU. 



