The other great groups consist of all the marsupials, and no others. It consists, therefore, of the single order, Marsupialia, and is called Didelphia.
Another group of mammals is made up of two genera only—the duck-billed platypus, or Ornithorhynchus, and the Echidna, two most interesting forms, but which cannot be further noticed here. They form, by themselves, a theme amply sufficient for an article, or even half a dozen articles.
As to its zoölogical relations, then, we may say that the kangaroo is a peculiarly modified form of a most varied order of mammals (the Marsupials), which differ from, all ordinary beasts (and at the same time differ from man) by very important anatomical and physiological characters, the sign of the presence of which is the coexistence of marsupial bones with an infected angle of the lower jaw.
We may now proceed to the next subject of inquiry, and consider the space relations (that is, the geographical distribution) of the kangaroo, its family, and order. I have already incidentally mentioned some countries where marsupials are found, but all of those were more or less remote. To find living, in a state of nature, any member of the kangaroo's order, we must at least cross the Atlantic.
When America was discovered by the Spaniards, among the animals found there, and afterward brought over to Europe, were opossums, properly so called—marsupials, of the family Didelphidæ, which extend over the American Continent, from the United States to the far South. These creatures were the first to make known to Europeans[1] that habit of sheltering the young in a pouch which exists in the kangaroo, and which habit has given the name Marsupialia to the whole order. But, though this habit was duly noted, it is not strange that (being the only pouched forms then known) the value of the peculiarity should have been under-estimated. It is not strange that they should have been regarded as merely a new kind of ordinary flesh-eating beasts, since in the more obvious characters of teeth and general form they largely resembled such beasts. Accordingly even the gi-eat Cuvier, in the first edition of his "Règne Animal," made them a mere subdivision of his great order of flesh-eating mammals.
But, to find any other member of the kangaroo's order (besides the Didelphidæ), in a state of nature, we must go much farther than merely across the Atlantic; namely, to Australia or the islands adjacent to it, including that enormous and unexplored island, New Guinea, which has recently attracted public attention through the published travels of a modern Baron Munchausen.
To return, however, to our subject. To find marsupials at all, we
- ↑ The following are some among the earlier notices of these animals: "Histoire d'un Voyage fait en la Terre du Brésil," par Jean de Léry, Paris, 1578, p. 156. Hernande's "Hist. Mex.," p. 330, 1626. "Histoire Naturelle des Antilles," Rotterdam, 1658. "Anatomy of an Opossum," Tyson, Phil. Trans., 1698.
