VOL. XXIV.] PHILOSOPHICAL TRANSACTIONS. Ill 



either. And when I have mentioned the auditory nerves to be large likewise 

 for the same reason, to give them a quick sense of hearing any sudden noise, 

 and so to avoid the danger, these were the greatest remarks I made upon the 

 nerves. It was observed that it saw best in the twilight, and not so well in the 

 bright sun, which I was easily brought to believe, because it was then to seek 

 out for its prey. In the eye I observed the membrana nictitans: the glandula 

 lachrymalis was large and oblong; there was the musculus Septimus suspensorius; 

 and the crystalline humour was large, very transparent, and.almost of a globular 

 figure; the eye or iris black. '(v-^q "^wft V. q 



The Anatomy of those Parts of a Male Opossum that differ from the Female. 

 By William Coiuper, F.R.S. N° 290, p. 1576. '■ 



The singular contrivances of the sexual organs of the opossum render the 

 anatomy of them very desirable, I may say entertaining, to those who have a 

 taste for such inquiries. Comparative anatomy, instructive as it is, does not 

 escape the censure of the vulgar ; though the greatest illustration of the use of 

 parts are not only to be had from thence, but the very existence of several or- 

 gans in human bodies have been made known to us by discoveries first made in 

 the bodies of quadrupeds. The circulation of the blood, and the passages for 

 the chyle and lympha would have been as little known to us as our predecessors 

 were it not for dissections made on the bodies of several animals. 



This male opossum, as well as the female, dissected by Dr. Tyson, was 

 brought from Virginia, and presented to the Royal Society j and was also 

 kept alive in their repository; but falling from its meat, it languished and 

 died: the cause of its death appeared to be from a mortification of the 

 duodenum, immediately below the pylorus, which seemed to arise from a 

 quantity of hay, that had been collected in the stomach, and matted together 

 in the shape before described, and figured the hairy tophus the Dr. found 

 in the stomach, but I could not find any hair in this; this wad of hay slipping 

 out of the stomach, it stuck in the duodenum, which together with the viscid 

 matter that involved it, completely obstructed the passage in that gut, as well as 

 that of the gall into the gut, which appeared from the distention of the liver 

 as well as the fullness of the gall bladder. The omentum, which in this 

 animal is only fastened to the bottom of the stomach, had also suffered a gan- 

 grene, as had almost the whole intestinal canal. ^ 



Besides the organs employed in generation, the male opossum differs exter- 

 nally from the female, there being no marsupium or pouch to receive the young 

 ones; nor are there any muscles inserted into the skin of the abdomen spring- 

 ing from the ossa niarsupialia, as Dr. Tyson calls the bones, which may deserve 



