( i58<$ ) . 
Thus, Sir, we fee Nature in thefe Inftances, as you muft 
have frequently taken notice of in others, accomplifh the 
fame ends by different Methods. Although there arc 
no VeJicuU Semindes in this Animals , as in Dogs, 
' Weafels, ^c. yet we find \t% Penis without a Bone in it, 
as in thofe Creatures 3 but then we rricet here with ad- 
ditional Contrivances to maintain its Ereftion : Not only 
fjg, the Sphin&er Ivlnfck of the Cloaca of the Male Opojfum, but 
that of the Female alfo clofcly embraces its Penis in Coi- 
tion^ and efftciually retard the refluent Bloud from its 
lig, <j . Corpora Cavernofa, by comprefGng the Veins of the Penis E. 
Nor could the Penis of this Animals be fram'd like that 
in Boars, Raml^i, Bulls, &c. in whom the Corpora Cavcrnofa 
are too large,when not erefted, to befecured within the 
Cloaca of this Animal. If in this I have been tedious, it 
maybe fome cxcufc^, I had not time to make it (horter. 
Who am 5 
Tour Obliged Humble Servant^ 
William Cowper. 
The Explanation of the Figures. 
Fig. I. 
SHews the external appearance of the Genitals of the 
Male Opojfum^ fomewhat lefs than the Life. 
A B c c. The Anus or Cloaca. A its lower part v/hich 
leads to the Return. B its upper part or Orifice of the 
Vr^putium^ whence the Urine and Penis is extruded, 
c c. Two fmafl Apertures, whence the yellowilh co* 
Icur'd Liquor, that had the peculiar Fi^tor of the Am- 
mal^ had its Exit. D. The 
