168 



The Opossum is very prolific, bringing forth two and sometimes even 

 three litters each year. The female produces young when a year old. 

 The first litter remains with the mother about two months, by which 

 time a second brood is in the pouch. Both litters remain in the vicinity 

 of the mother until autumn, by which time they are old enough to care 

 for themselves. The number of young found in the pouch is usually less 

 than the number born. Six is the smallest and thirteen the greatest 

 number observed by Audubon and Bachman, whereas fifteen were found 

 in the uterus of one female. Of course thos? in excess of the number of 

 teats must perish, as those first attached seem incapable of losing their 

 hold. 



The same authors conclude that the young are licked or shoved into 

 the pouch by the mother. The pouch is distended by the jaws at times, 

 the female lying on one side, with the body drawn into the shape of a 

 ball, so that the parts of the genital passage reach the edge of the marsu- 

 pial pouch ; then, as the young appear, they are licked into the pouch. 



Experiments made by Audubon and Bachman indicate that the young 

 instinctively find and seize the teat. The young, when taken from the 

 uterus and rolled in warm cotton, drew the fibers into the mouth. More- 

 oveA when six of a brood of ten were removed from the teats, and three 

 young of another litter, and double the size, were put back in the pouch, 

 they were found the next morniug attached to the teats, together with 

 two of her own which were returned with them. 



The following abstract by Prof Owen from Dr. Chas. D. Meigs "On the 

 Reproduction of Didelphys virginiana," in American Philosophical So- 

 ciety, April, 1847, 1 transcribe, as adding to our knowledge, of the peculiar 

 mode of reproduction in this species : 



"Dr. Meigs reckons the utero-gestation of a female Didelphys virginiana, which bred 

 in captivity, as extending from the 18th February to the 7th March — a period of seven- 

 teen days — when she brought forth thirteen young, which were found attached to as 

 many nipples. The mainmaj began to enlarge four days prior to birth. Oa the li.h of 

 March she was observed to lay on her side, with h»fr nose turned inward between her 

 legs towards her belly, and took scarcely any notice of the keeper's hand when intro- 

 duced into the box. The transit of the fostuaea was probably iu preparation or operation 

 at this time. The young, observed on the 7th, and which were certainly not in the 

 pouch on the 5th, and probably not until the night of the 6th, were naked, of a rose 

 tint, each three and a half grains in weight, and eight-ienths of an inch in length to the 

 end of the tail; adhering strongly to the nipple, sucking actively, and clinging to the 

 fur by the unguicnlate digits of their fore limbs, which they freely used. One survived 

 separation from the nipple one hour and twenty-nine minutes, turned itself over and 

 moved round the glaas in various directions, respiring by the nostrils twenty-two times 

 per minute, and ejecting bubbles of milk from its mouth. The hind limbs were each a 

 mere bud, with feeble indications of toes without claws. The tongue is very large — one- 



