1848.] 4.1 



alive through a cool night in a room containing no fire, anJ still evidenced a 

 slight motion at 12 o'clock on the following day. 'l"he teats of the mother, 

 after the young had been gently drawn off, measured an inch in length, having 

 been much distended, and appeared to have been drawn into the stomach of the 

 young. 



March IGth. — The dark colour of the eye can be seen through the transparent 

 skin, but it is still perfectly closed. A few hairs have mude their appearance 

 on the moustache. I'he orifice of the ears beginning to be developed. Nails 

 visible and sharp. The porich of the young females is quite apparent, and the 

 sexes may be determined as soon as born. They voided urine and excrement — used 

 their prehensile tails, which were seen entwined around the necks of others even 

 at a week old. 



February and March, 1847. Made a number of observations on a large number 

 of females. As they, however, all had young in their pouches before I procured 

 them, I will only notice one experiment made in order to ascertain the manner 

 in which the young became attached to the teats. 



March 11th.— Conjecturing that the young were aided by the mother in finding 

 the teat, and believing that she would not readily adopt the young of another, or 

 afford them any assistance, I removed six of the ten which composed her brood — 

 returned two of her own to the pouch, together with three others, fully double 

 the size, that had been obtained from another female. She was soon observed 

 doubled up, with her nose in the pouch, and continued so for an hour, when she 

 was examined, and one of her own small young was found attached to the teat. 

 Seven hours afterwards she was again examined, and both the small ones were 

 attached, but the three larger ones still remained crawling about the pouch. 



March 12ih. — The mother seemed now to have adopted the strangers, and the 

 whole family of different sizes were deriving sustenance from her. 



February 11th, 1848.— Having received from the country a large female that 

 appeared to be impregnated, I this day dissected her. As soon as the uterus was 

 removed from the body of the animal, which had just been killed and was yet 

 warm, I observed the whole mass in irregular motion. There were nine young 

 that would evidently have been produced in one or two days. Three were con- 

 tained in one department and six in the other. They lay embedded in a thick 

 dark-brown mucous substance, which filled and greatly distended the sacs. They 

 possessed more life and motion than I had previously been led to suppose. One of 

 them moved several inches on the table, and survived two hours. I attempted 

 to weigh this uterine fcetus, and as far a.s I could ascertain with an imperfect 

 pair of scales, it weighed 3 grains. 



Although naturalists at the present day could scarcely enter'ain a doubt that 

 the process of generation in this species did not differ materially from those of 

 the Kangaroo and other Marsupialia, yet I am not aware that the young of the 

 Virginian Opossum had been previously detected in the uterus. 



The short period of gestation, the reluctance of many of them in copulating in 

 a state of confinement, unless perfectly domesticated, rendered the discovery one 

 of considerable difficulty. I have moreover found, that during the period of ges- 

 tation, the females, like those of some other species, particularly the Bear, can 

 seldom be found. 



In February, 1847, by offering premiums to servants, I procured from various 

 localities, in three nights, 35 opossums, and there was not a single female in 



