Page:Mammals of Australia (Gould), introduction.djvu/24

 under the influence of monsoons, and rains more or less regular occur in their proper seasons. Speaking generally, however, Australia may be characterized as one of the driest and most heated countries of our globe; for, although an island in the strictest sense of the word, it is so extensive that the surrounding seas have little influence upon the distant interior, which must still be regarded as a great sterile waste, destitute of mountains sufficient to attract the moisture requisite to form navigable or other rivers. In writing this in 1863, when travellers have crossed the country and so many valuable discoveries have lately been made, I am willing to admit that this great desert is here and there relieved by higher lands which will ultimately become useful to the enterprising settler, and that, in all probability, many fine and extensive oases have yet to be brought to light; but, at the same time, I believe there will always be considerable uncertainty in the seasons of the interior of this great land. In southern latitudes we know that this is the case, while in the north a wet or a dry monsoon greatly alters the face of the country, and exerts a powerful influence on animal and vegetable life. Hence it is that the scanty fauna of this part of Australia is so organized that it is able to exist without water: the various species of Rodents, such as the members of the genera Mus and Hapalotis, and the Wombats, Lagorchestes, and Bettongias, and other Kangaroos, are thus constituted; and it will be recollected that, when speaking of the Halcyons and other large Kingfishers in the 'Birds of Australia' I stated that I believed they never partook of this element, their food consisting of lizards and insects, to which, in like manner, it was not essential. The Australian mammals must, however, be put to severe straits occasionally, not from the want, but from the superabundance of water,—a wet monsoon in the north, and the heavy rains which occasionally occur in the south, deluging the basin-like surface of the interior and rendering it untenable, and obliging them to retire to the higher ridges until the drought, which generally ensues, has restored it to its normal condition. The districts,