4(5 THE OSTEOLOGY AND MYOLOGY 



The natural history of this quadruped has been so fully elucidated by Audubon and 

 Bachman, that little remains to be learned. It is strictly nocturnal, like many, if not 

 most marsupials. The females, indeed, hardly leave their retreats at all during the two 

 months of uterine and pouch gestation. As the teeth show, it is omnivorous ; any quad- 

 rupeds or birds that it can overpower, eggs, reptiles, insects and worms, berries and 

 fruits of all sorts, form its food ; it will at times eat carrion, half a dozen individuals 

 having been found at one time feeding on a dead cow. At certain seasons, especially in 

 the fall, it acquires a deposit of fat, chiefly in tlie subcutaneous tissue, rivalling in amount 

 that of a well-fed hog, and Avhen in this condition its flesh is palatable. Particularly when 

 thus fortified, it may ftist a long time without inconvenience ; and under ordinary circum- 

 stances can survive for three or four weeks without food or water. An individual upon 

 which I was experimenting passed this length of time with no other food than its own 

 tail, which it gnawed off and ate during the last few days before it was killed. Accord- 

 ing to Dr. Bachman it sometimes becomes quite tame ; but all the individuals I kept in 

 confinement remained to the last as sullen and ferocious as when first caught. It has no 

 voice beyond a low growl, and a sort of hiss when provoked ; nnder the influence of fear 

 or anger a transparent viscid saliva drops constantly from the mouth. Its personal habits, 

 in close confinement, are filthy ; the odour, which under the most favorable circum- 

 stances is not agreeable, becomes very disgusting after a time. To a common observer 

 it appears dull and uninteresting in confinement, passing the day huddled in a corner, 

 and the hours of darkness in persistent endeavors to escape. It ordinarily, or at least 

 for a long while after capture, refuses food by daylight, and resents too familiar approach 

 by a sinister expression, and the display of a formidable set of teeth. If fortitude under 

 physical pain, and acceptance of death without dismay, be tests of courage, the opossum 

 Ls one of the bravest of beasts ; no amount of torture can draw from it a sign of suffer- 

 ing. fSuch endurance, joined with remarkable cunning, enables the animal to feign death 

 so perfectly that it frequently escapes, and not seldom retaliates upon its persecutors with 

 an unexpected wound from its sharp teeth. These are well known traits, that have given 

 to the English language a proverbial expression of peculiar significance. 



THE TEETH. 



Dental Formula : — Inc. f^ ; can. ]-^ ; prem. |^ ; mol. ~ ; = g = 50. 



As the foregoing formula shows, four kinds of teeth are present, and indicate an omniv- 

 orous animal of carnivorous propensities. In number the lower teeth only differ from the 

 upper in being one less on each side, by the absence of one pair of incisors. In size and 

 shape, however, the upper and under teeth, especially the molars, differ considerably. 

 The dentition apparently comes nearest to that of Thylacinus cynocephalus, among Didel- 

 phia, and thus resembles that of the Canidce. (For general comparisons of the teeth with 

 those of other marsupials, see Owen, Comp. Anat. and Phys. Yert., in, p. 285 et seq.) 



Upper Jaw. The median pair of incisors are longer than the rest, and stand a little 

 apart from the succeeding ones. The others are in close juxtaposition, though not usually 

 in actual contact ; and of the same size. All are simple, straight, short, somewhat com- 

 pressed, with slightly enlarged head, not pointed or edged, but obliquely truncated, 



