MAY 7 1900 



Contributions to the Embryology of the 

 Marsupialia. 



By 



Jas. P. Hill, B.Sc.(Ediii.), F.L.S., 



Demonstrator of Biology in the University of Sydney, N.S.W. 



With Plates 1 and 2. 



II. On a Further Stage in the Placentation of Perameles. 



In the present paper I deal with a stage in the placenta- 

 tion of Perameles somewhat later than my previous Stage D 

 (1). Beyond the demonstration of the persistence of the entire 

 yolk-sac wall, no strikingly new facts have been brought to 

 light in the investigation, but I have been enabled to essen- 

 tially confirm my previous account, and also to add some 

 fuller information on certain points of detail, especially as 

 regards the yolk-sac vessels. In addition, I give an account, 

 in the sequel, of the foetal membranes of a species of 

 Macropus, for comparison with those of Perameles, and I 

 also take this opportunity of offering some further remarks 

 on the phenomena of parturition, and of correcting a mis- 

 interpretation contained in my previous account of that 

 process, since an extended investigation^ into the morpho- 

 logy of the female urogenital organs of Perameles, with 

 special reference to the phenomena of parturition, has con- 



^ Communicated to the Linnean Society of New South Wales, March, 

 1899. 



VOL. 43, PART 1. — NEW SERIES. A 



