2 JAS. P. HILL. 



vinced me that " the common uterine canal " of my former 

 paper is in reality formed by the union posteriorly of two 

 median vaginal cul-de-sacs^ which constitute a median 

 vaginal apparatus homologous to that existing in other 

 Marsupials. If for the above misleading expression the reader 

 will substitute common median vagina, the main facts in my 

 previous short account of the process of parturition remain 

 substantially correct. 



It is with much satisfaction, in view of my interpretation 

 of the allantoic placenta of Perameles as a primitive feature 

 of its organisation, that I am thus enabled to bring its appa- 

 rently peculiar parturition phenomena into line with those 

 occurring in certain other Marsupials, which, like Perameles, 

 give birth to the young through a direct median passage. 

 Further, the investigation above referred to has led me to 

 the conclusion that the urogenital organs oi Perameles are in 

 a condition which can only be described as persistently 

 embryonic, and which is without doubt much more primitive 

 than that existing in any other Marsupial hitherto described, 

 a conclusion which I believe serves materially to strengthen 

 the position I have taken up as regards the significance of 

 the occurrence of an allantoic placenta in the genus. 



My work for the past year has been carried out with the 

 aid of a grant from the Royal Society, to whose Committee I 

 desire to express my grateful thanks. 



Stage D. — P. obesula. 



The female, a specimen of the short-nosed Bandicoot, P. 

 obesula, upon the examination of whose genital organs the 

 account of the present stage is based, came into my hands a 

 few hours after death. Post-mortem change, however, was 

 not at all apparent, and the genital organs were at once cut 

 out and preserved in picro-nitric acid. 



Both uteri were much enlarged ; the right measured 22 mm. 

 in length by 11 mm. in breadth, the left 21 mm. by 15 mm. 

 Each contained a siugle embryo (PI. 1, fig. 3), measuring in 



