540 PHILOSOPHICAL TRANSACTIONS. [aNNO IJQS. 



of the uterus I detected a substance, which appeared organized; it was enveloped 

 in the gelatinous matter, and so small as to make it difficult to form a judgment 

 respecting it; but when compared with the foetus after it becomes attached to the 

 nipple, it so exactly resembled the back-bone with the posterior part of the skull, 

 that it is readily recognized to be the same parts in an earlier stage of their 

 formation. 



I had an opportunity on the 22d of August, 1 794, of reading these observa- 

 tions, and showing the annexed drawings, to Mr. Considen, who was 7 years an 

 assistant surgeon to the general hospital in New South Wales, and who had paid 

 much attention to this subject. During his residence in that country, he met 

 with the uterus of the kanguroo in its enlarged state, 3 different times; in all 

 of these the degree of distension was nearly the same; the gelatinous matter 

 contained in the uterus, examined immediately after death, was of a bluish white 

 colour, in consistence like half-melted glue, and so extremely adhesive as to be 

 with difficulty washed off from the fingers; the internal membrane of the uterus 

 was very vascular, and even more so than that of the lateral canals. The oval 

 enlargements of the fallopian tubes contained a gelly similar to that found in the 

 uterus, but thinner in consistence. He found also the other appearances which 

 I have already described, but in only one of them was the foetus sufficiently ad- 

 vanced to be detected, and that resembled the back-bone delineated in one of 

 the annexed drawings. 



Immediately after parturition, the parts are nearly brought back into their 

 original state; the only circumstance deserving of notice is, that the opening 

 leading directly from the uterus to the vagina, which is not met with in the 

 virgin state, after being enlarged by the passage of the fcetus, forms a projecting 

 orifice, and almost wholly conceals the meatus urinarius. Were we to consider 

 the uterus and its appendages in the unimpregnated state, the 2 lateral canals 

 would appear to be the proper vaginae, particularly as they begin at the meatus 

 urinarius, which is commonly placed at the entrance of the proper, or true 

 vagina, and receive the penis in coition, the end of which is pointed to fit it for 

 that purpose; in some species of the opossum the male has a double glans, each 

 of them pointed, and diverging from the other, so as to enter both canals. But 

 when we find these canals in the impregnated state forming with the uterus one 

 general reservoir of nourishment for the foetus, and ail communication during 

 that period between them and the vagina cut off, we are led to consider them 

 more immediately as appendages to the uterus than the vagina. 



The female kanguroo has 2 mammae, and each of them has 2 nipples; they 

 are not placed on the abdominal muscles as in most quadrupeds, but are situated 

 between 2 moveable bones connected with the os pubis, peculiar to this tribe of 

 animals; and the mammae are supported on a pair of muscles which arise from 



