434 DR. E. C. STIRLING ON THE [NoV. 5, 



The literature bearing on these and other allied points has been 

 concisely summarized by Messrs. Lister and Fletcher in the ' Pro- 

 ceedings ' of this Society for 1881, p. ^11. These authors also 

 there record a condition of patency of the aforesaid opening in 

 some species in which its existence had not been previonsly noted. 

 I observe that while " no one as yet seems to have had the good 

 fortune to find an embryo in any part of the vaginse," Messrs. Lister 

 and Fletcher nevertheless come to the following conclusion, which I 

 quote : — " In the very early condition of the Macropodidse the 

 median canal is closed." Again they say : — 



" \x\ some genera, viz. Macropus,Halmaturus, Petrogale (Dorcopsis 

 and Dendrolagus ?), an opening is formed in the median canal to give 

 passage to the young. This may take place in early life (Halmaturus), 

 or not till young are about to be produced {Macropus). In the 

 species Macropus major, however, this opening may or may not 

 exist, and the young may be transmitted either through the median 

 or the lateral canal." 



For one species of Kangaroo, at least, this question of the route 

 taken by the embryo may be considered settled, for I have been for- 

 tunate enough to obtain a specimen of the female organs of Osphranter 

 erubescens, Scl., which contain the embryo in course of transit along 

 the passages. 



The organs in question, having been extracted by unskilled hands, 

 were somewhat mutilated in the process, and further the operator, 

 a cook in the camp of rabbiters, being a man of some intelligence and 

 himself curious on the subject of marsupial parturition,had commenced 

 an examination on his own account. These circumstances answer 

 for the fact that the specimen is not anatomically complete, the 

 lower part of the right lateral canal, a small part of the lower extremity 

 of the left, and almost the whole of the urogenital passage having 

 been cut away or left behind in the process of extraction. In the 

 partial examination to which the specimen had been subjected before 

 it came into my hands, the median canal had also been partially 

 slit up from the front ; and in view of existing incisions I found it 

 convenient to continue the dissection from this side instead of from the 

 posterior (dorsal) aspect, by which the parts can be more satisfactorily 

 displayed. Fortunately the essential parts and their relations to 

 one another had not been disturbed, and the following is a brief de- 

 scription of the specimen, represented in the accompanying drawing 

 (fig. 1, p. 435) of about four fifths of the natural size. 



The embryo, closely enveloped in a thin amnion, was 11, 6, 

 and 5 mm. in the long, antero-posterior, and lateral diameters re- 

 spectively ; its anterior extremities distinctly five-partite, and the 

 posterior distinctly three-partite and smaller than the anterior. The 

 eyes just discernible as dark rings. It was suspended by a cord, 

 which was extremely attenuated for some little distance from its 

 point of attachment, though on imravelling this it was found to be 

 distinctly membranous even at its thinnest part. The exact method 

 of attachment of the cord to the body of the embryo cannot be 

 stated with exactitude in this specimen, owing to the laceration which 



