120 
VIRGINIAN OPOSSUM. 
procuring specimens, especially our relative Colonel Haskell, Mr. Joilvson, 
and James Fisher, Esq., a close observer and intelligent naturalist. The 
latter, by his persevering eflbrts, pursued for some years at Jordan’s 
Mills, on the upper waters of the Edisto, obtained two females in May, 
1840, in the particular state in which be knew we W'ere anxiou.s to procure 
them, and brought them to us without having been previously aware that 
we had published the facts a year before. 
The Opossums we were enabled to examine were dissected on the 11th, 
14th and 18th February, 1848, and on the 12th and 22d May, 1849, Some 
of these had advanced to near the time of parturition. The young of those 
brought us by Mr. Fisher each weighed 2i grains. Those of one, sent 
us by Col. Haskell, weighed 3 grains ; and the young of another which we 
obtained by a Cmsarian operation, at a moment when all the rest had 
been excluded, and this individual alone remained, weighed 4 grains. 
We remarked, that this however was a little the largest of six that 
composed the family, five of which were already in the pouch and attached 
to the teats. The largest one weighed 3f, and another 3i grains. 
The weight, then, of the young Opossum at the moment of birth, is between 
3 and 4 grains, varying a little in different specimens as is the case in 
the young of all animals. 
The degree of life and animation in young Opossums at the mo- 
ment of birth has been greatly underrated. They are neither abortions, 
as Blumenbaoh represented them, nor as Dr. Barton has described them— 
not foetuses, but gelatinous bodies, weighing about a grain more or less, 
seven of them together weighing 10 grains”— but little creatures that are 
nearly as well developed at birth as the young of the white-footed mouse 
and several other species ofrodentia. They are covered by an integument, 
nourished by the mammm, breathe through nostrils, perform the operations of 
nature, are capable of a progressive movement at the moment of their birth, 
and are remarkably tenacious of life. The individual which was dissected 
from the parent in the manner above detailed, moved several inches on the 
table by crawling and rolling, and survived two hours ; the thermometer in 
the room was at the time standing at 66° Fahrenheit. The period of gesta- 
tion is from fifteen to sixteen days. We received a female from a servant 
who informed us, that he had that morning seen it in intercourse with 
the male. We first saw the young on the morning of the 17th day. Our 
friend Dr. Middleton Michel, a gentleman of high scientific attainments, 
and who had long been engaged in investigating the characters and habits 
of this .specie,s, in a communication made to us, (Trans, of the Acad. Nat. 
Sciences, April, 1848, p. 46,) assured us from his personal observation in 
which he was careful to note the hour of the day, the exact period is 
