514 
The species shows a tendency to become smaller and darker 
toward the south, becoming the subspecies pigra of Bangs, which is 
found in Georgia, Florida, and the Gulf states. 
Gestation in the opossum lasts about seventeen days. From six 
to aS many as sixteen, or more, may be produced in a litter, and 
available evidence goes to show that there may be three litters 
during the year—all between January and the last of June. The 
female is often found accompanied by the young of more than one 
litter. At parturition the female lies on one side, curling up so as to 
bring the vulva near the opening of the marsupial sac. The young 
as brought forth are pushed into the sac and attach themselves 
to the teats, remaining continuously attached for four weeks, and 
for much of the time during the three weeks following. They are 
only a quarter of an inch long and weigh but four grains at birth. 
They are hairless, and their eyes and ears are closed. The mouth 
is a minute opening just able to receive the slender teats of the 
mother. Growth is very rapid. The young leave the pouch when 
about two months old, weighing then 400 to 450 grains. Even at 
the first, however, they exercise all the functions of other young 
animals, breathing, eating, digesting, defecating, etc., and are by no 
means the unformed egg or embryonic mass they were once sup- 
posed to be. The tail is prehensile, and the very young are able to 
support themselves by one twentieth of its length. 
In general the adults live separately, but pair a short time during 
the rutting season. At this time the males are exceedingly pug- 
nacious and jealous of each other. They hide in hollow trees, logs, 
etc., but are said to be of a wandering habit, not remaining long in 
one locality. 
Owing to peculiarities of anatomical structure, the movements 
of the opossum, if not graceful, are at least unusually free and 
varied. The thumb and hallux are both opposable, and Coues 
asserts that the opossum is functionally as truly four-handed as are 
most of the monkeys. The movements of the feet as a whole are 
nearly as free as those of the human hand. The body is easily 
curled into a ball, and lateral movements are unusually free. The 
tail itself serves as a fifth hand, and possesses so much flexibility 
and strength that the animal can easily support itself by a small 
portion of the tip. It is capable not only of flexion in a single plane, 
but also of a twisting motion by which it can be wrapped in a spiral 
