66 FEMALE UROGEXITAL ORGANS OF PERAMELES, 



In the connective tissue following on the posterior end of the 

 median vagina are incorporated the fibrosed remnants of an 

 allantoic stalk, which forms an integral part of the tissue, and is 

 only distinguishable therefrom by its more homogenous appear- 

 ance and its slightly deeper-staining qualities. Behind this the 

 pseudo-vaginal cleft appears and posteriorly there is present in it 

 another portion of an allantoic stalk with very much the appear- 

 ance of the stalks in specimen W. It is invested by a delicate 

 layer of the surrounding tissue, so that the lumen of the passage 

 is completely blocked. The matrix of the stalk is fibrosed and 

 contains numerous connective tissue cells. 



viii. P. obesnla, with blastodermic vesicle in uterus. (Stage B 



of previous paper). 



This female proves to have been in her first pregnancy. The 

 two median vaginal canals end blindl}- without opening into each 

 other, just as in the virgin previously described. Fig. 21 repre- 

 sents a section through the urogenital strand of this specimen. 

 Except in size, it in no way differs from the section through that 

 of the virgin shown in fig. 8. 



ix. P. obesula, with two 12-5 mm. embryos in the uteri. 



Like the preceding this female is also in her first pregnancy, 

 and, as in her, the two median vaginal canals end blindly and 

 separately. The lumina of the two cul-de-sacs are separated by 

 the common wall with a least average thickness posteriori}'- of 

 •37 mm. There is no sign of any thinning of the wall nor any 

 indication suggesting the subsequent union of the two canals. 



The only point of importance in connection with the urogenital 

 strand is the fact that the connective tissue lying between the 

 lateral vaginal canals is now very vascular (fig. 22, c.t.), numerous 

 large and small veins, running mainly longitudinally, being dis- 

 tributed through it. 



General Remarks ou Parturition. 



If now Tve shortly summarise the facts concerning the parturi- 

 tion phenomena contained in the preceding pages, we reach the 



