44 FEMALE UROGENITAL ORGANS OF PERAMELES, 



the very considerable length of the urogenital strand, the various- 

 structures connected with its anterior end, viz., the bladder, the 

 uteri and their appendages, and the vaginal cfeca, are situated in 

 the abdominal cavity well in front of the anterior end of the 

 pubic symphysis. The strand itself is the only portion of the 

 urogenital organs which lies in the proper pelvic cavity. At its 

 posterior end, at the hinder margin of the pubic symphysis, the 

 strand becomes continuous with the rounded thick mass in which 

 the urogenital sinus and cloaca are situated. At the anterior end 

 of the strand the urethra, occupying its mid-ventral line, expands 

 into the bladder, while the lateral vaginal canals, occupying the 

 dorso-lateral regions of the strand, are produced forwards into two 

 large thin-walled outgrowths, — the vaginal cteca, — separated from 

 each other by a common partition wall (Plate i., fig. 1, vag.c), and 

 lying immediately dorsal of the bladder, between it and the uteri. 

 The posterior ends of the latter, as well as the median vaginae, lie 

 imbedded dorsally in the connective tissue at the anterior end of 

 the strand. In Plate i., fig. 1, the urogenital organs are repre- 

 sented as viewed from the dorsal aspect. The apex of the bladder 

 (bl.) is just visible below the enormous bilobed vaginal caeca (vag.c). 

 Each of the latter is seen to contract posteriorly and to pass back 

 as the lateral vaginal canal {l.vag.c.) in the urogenital strand (u.s.). 

 Dorsally to the vaginal caeca the two uteri (ut.) lie side by side. 

 Their contracted posterior ends — uterine necks (ut.n.) — pass back 

 to become imbedded together with the median vaginae in the 

 connective tissue of the anterior end of the urogenital strand. In 

 the figure the rectum (red.) and the cloaca (c/.)are shown opened 

 up, exposing the opening of the urogenital sinus {o.u.s.) into the 

 latter. 



Peritoneal Relations of the Urogenital Organs. 



When the peritoneum covering the ventral face of the rectum 

 is traced back, it is found to leave the surface of the latter and 

 to be reflected forwards on to the dorsal surface of the urogenital 

 strand, just posterior to the anterior end of the pubic symphysis. 

 The peritoneal pocket thus formed, corresponds to the recto- 



