The peculiar method of nourishing and protecting the young Marsupial after birth is of course well known. The young are born in a very immature and helpless condition, and are placed by the mother in her pouch. The mouth becomes permanently attached to the nipple of the dam, and the young creature remains thus for a considerable time, the milk being pumped into it by the mammary gland rather than sucked in by the efforts of the creature itself. The Marsupials are further characterised by the possession of an extra pair of bones in the pelvis, which function as supports for the pouch; by the peculiar and primitive arrangement of the reproductive organs; by their still poorly developed brain; and by their generally large number of teeth, which reach a total of fifty or fifty-two in some species, whereas forty-four is the ordinary maximum number in the main mammal group. This last is to be regarded as a character derived from the reptiles. [Illustration: FIG. 108.--Kangaroo, with young.] [Illustration: FIG. 109.--Newborn young of Kangaroo.] It is very interesting to observe how, in Australia, where the Marsupials have been free from the competition of other mammals, they have evolved along many of the same general lines as the higher group. We have indeed no marsupial whales, bats, or seals, but there is a mole, very similar in its appearance and habits to our European species, and a carnivorous type which closely resembles a wolf or jackal; again we have bandicoots, occupying the same place in nature as our rabbits and other rodents; tree-dwelling, squirrel-like forms; and kangaroos, which compare in their mode of life, if not in their appearance, with the cattle, deer, and antelopes of other countries. The Marsupials are illustrated in Figs. 108 to 113. This group, so far as can be judged from fossils, is considerably older than that of the higher mammals, and everything points to some marsupial type as a connecting link between the egg-laying Monotremes and the placental mammals. [Illustration: FIG. 110.--The Marsupial Mole.] [Illustration: FIG. 111.--Tasmanian Wolf, a carnivor-like marsupial.] [Illustration: FIG. 112.--Marsupials--Long-nosed Bandicoot.] [Illustration: FIG. 113.--Squirrel-like marsupial (_Phascologale penicillata_).]