VIRGINIAN OPOSSUM. 
119 
uterus, nor could an explanation of the peculiarity in the growth of the 
fetus be made until it was examined in its original bed. 
We have been so fortunate in five instances as to have procured speci- 
mens in which the young were observed in this position, and therefore 
feel prepared to speak with certainty. We are not aware that the young 
of the Virginian Opossum had been previously detected in the uterus. 
All our investigations were made in South Carolina, where this is a 
very abundant species. For some years we attempted to arrive at the object 
of our researches by preserving these animals in a state of confinement. But 
they were subject to many accidents : they frequently made their escape 
from their cages, and some of them became overburdened with fat and 
proved sterile, so that we did not succeed in a single instance in obtain- 
ing young from females in a state of confinement. From this cause the 
naturalists of Europe, and especially those of France, who were desi- 
rous of making investigations in regard to our Opossum, have been so 
long unsuccessful. Their usual complaint has been, “Your Opossums do 
not breed in confinement.” In this. Dr. Barton and our young friend Dr. 
Michel were more fortunate, but in both cases the young were produced 
before they were enabled to detect them in their previous existing posi- 
tion. We varied our experiments by endeavouring to discern the precise 
period when young were usually produced. We ascertained, by having a 
number of females procured with young in their pouches, that about the 
close of the first week in March, a little earlier or later, according to the 
age of the individual, or wmrmth, or coldness, of the previous winter, 
was the time when in this latitude this event usually occurs. Here, how- 
ever, another difficulty presented itself, which for several successive sea- 
sons, thwarted us in our investigations. In the third week of February 
1847, by offering premiums to the servants on several neighbouring plan- 
tations we obtained in three nights thirty-five Opossums, but of that 
number there was not a single female. A week afterwards, however, 
when the young were contained in the pouch, we received more females 
than males. From this circumstance we came to the conclusion that 
during the short period of gestation, the females, like those of some other 
species of quadrupeds, particularly the American black bear, conceal 
themselves in their burrows and can seldom be found. We then changed 
our instructions for capturing them, by recommending that they should 
be searched for in the day time, in hollow logs and trees and places where 
they had been previously known to burrow. By this means we were en- 
abled at different times to obtain a small number in the state in which 
we were desirous of examining them. We feel under great obligations 
to several gentlemen of Carolina for aiding us in our investigations by 
