Although fattening up against the winter, he, even in his most northern limits, does not hibernate, but may even be seen leisurely picking his way over the snow, probably tracking some unfortunate squirrel to its lair, which in due time is located, dragged out, and devoured. While assimilating his meal of flesh or fruit, Brer 'Possum likes to have all four hands at liberty, his hind feet being also graspers; and so he twists his tail round a convenient branch, and, hanging perdu, leisurely enjoys his feast. The opossum, like the rat—to which it has in aspect and many of its habits been likened—is a most prolific breeder, as many as from six to sixteen young being comprised in the litter. When born, they are immediately transferred to the somewhat capacious pouch, and remain there without venturing outside until they are about the size of an ordinary mouse.
A third and very distinct type of American opossums is the one represented on [page 380], which, from its mouse-like size and aspect, is commonly known as the Murine Opossum. The most distinct feature of this little animal is that, though a genuine marsupial, it has no pouch, but carries its young on its back, the little creatures twining their tails round that of their mother, and so securing a stable anchorage. Although thus loaded up and transformed for the time being into a sort of combination perambulator and feeding-flask, the happy but anxious parent pursues the even tenor of her way among the tree-branches and thicket-growths with almost unabated agility. This species, in common with Meriam's Opossum and the Woolly Opossum and several others which carry their young, to as many as a dozen in number, on their backs, are denizens of tropical South America. One of these, named the Philander Opossum, attains to the somewhat larger size of about 2 feet in total length, the long prehensile tail representing, however, the greater moiety of these dimensions.
The Selva.
South America has one other marsupial—the Selva—an animal which, while possessing the dimensions and much of the aspect of an ordinary rat, is remarkable as differing so materially in the character of its teeth and other structural points that it cannot be referred to any existing marsupial family. On the other hand, this type is found to coincide in the above particulars with species hitherto only known in the fossil state, and excavated from the same tertiary deposits in Patagonia which have been productive of the distant ally of the Tasmanian wolf. It is yet hoped by zoologists that the discovery of other interesting and possibly some supposed extinct mammals may reward the thorough exploration of the vast South American forests. The capture in the flesh of some form allied to the huge ground-sloths, such as the Mylodon and Megatherium, is, however, now considered to be quite beyond the pale of possibility.
Photo by Dr. R. W. Shufeldt] [Washington.
YOUNG OPOSSUM (NATURAL SIZE).
This is an interesting photograph, as it is reproduced life-size, and gives an excellent idea of the animal in its native land.
MONOTREMES, OR EGG-LAYING MAMMALS.
With this group or order of the Mammalian Class we arrive, as it were, on the borderland between the mere typical Mammals and Reptiles. In the last group, that of the Marsupials, it was observed that the young were brought into the world at an abnormally early and helpless phase of their existence, and usually consigned, until able to see and walk, to a variously modified protective pouch. With the Monotremes a yet lower rung in the evolutional ladder is reached, and we find that the young are brought into the outer world as eggs, these being in the one case deposited in a nest or burrow, and in the other carried about by the parent in a rudimentary sort of pouch until they are hatched.