have, as we have seen, to go to the New World. To find nearer allies of the kangaroo, we must go to the newest world, Australia; newest because, if America merited the title of new from its new natural productions as well as its new discovery, Australia may well claim the superlative epithet on both accounts. We have found an indication, in the name Botany Bay, of the interest excited in the mind of Sir Joseph Banks by the new plants as well as by the new animals of Australia. And, indeed, its plants and animals do differ far more from those of the New World (America) than do those of America from those of the Old World.
Marsupials, in fact, are separated off from the rest of their class—from the great bulk of mammals—the Monodelphia—no less by their geographical limits than by their peculiarities of anatomical structure.
And these geographical limits are at the same time the limits of many groups of animals and plants, so that we have an animal population (or fauna) and a vegetable population (or flora) which are characteristic of what is called the Australian region—the Australian region, because the Australian forms of life are spread not only over Australia and Tasmania, but over New Guinea and the Moluccas, extending as far northwest as the island of Lombok, while marsupials themselves extend to Timor.
In India, the Malay Peninsula, and the great islands of the Indian Archipelago, we have another and a very different fauna and flora—those, namely, of the Indian region, and Indian forms of life extend downward southeast as far as the island of Bali. Now, Bali is separated from Lombok by a strait of but fifteen miles in width. But that little channel is the boundary-line between these two great regions—the Australian and the Indian. The great Indian fauna advances to its western margin, while the Australian fauna stops short at its eastern margin.
The zoölogical line of demarkation which passes through these straits is called "Wallace's line," because its discovery is due to the labors of that illustrious naturalist, that courageous, persevering explorer, and most trustworthy observer, Alfred Wallace, a perusal of whose works I cordially recommend to my readers, since the charm of their style is as remarkable as is the sterling value of their contents. Mr. Wallace pointed out that not only as regards beasts (with which we are concerned to-day), but that also as regards birds, these regions are sharply limited. "Australia has," he says, "no woodpeckers, no pheasants—families which exist in every other part of the world; but instead of them it has the mound-making brush-turkeys, the honey-suckers, the cockatoos, and the brush-tongued lories, which are found nowhere else upon the globe."
All these striking peculiarities are found also in those islands which form the Australian division of the archipelago, while in those
