Page:A sketch of the physical structure of Australia.djvu/105

93 the latitude and the height above the sea, but also with the distance of the locality in longitude. There are, for instance, very few mammals, I believe, and not many birds even, that are common to Western Australia and New South Wales, although the climate generally and the rocks and every other circumstance of the two countries is frequently the same. The eucalypti of the one country, which give the general feature to the forests and the scenery, or which are the most abundant, are not the same eucalypti which are most abundant in the other. There are kangaroos in both, but not the same species of kangaroos; the difference in the common parroquets and other birds that one sees continually about one, is most striking whenever one passes from one colony to another. This difference is most striking in passing from Sydney to Swan River, but it is quite perceptible in moving from any colony to another, Port Phillip to Adelaide, or Van Diemen's Land, for instance. The same is the case even with the marine mollusca to a very considerable extent, more especially perhaps the littoral species. I believe I should be correct in saying that there is a greater difference found in the species of the commoner plants and animals (including birds) in passing from the neighbourhood of Sydney to that of Adelaide, and certainly in going from Sydney to Swan River, though the latitude and the climate is so nearly the same, than in going from Sydney along the N.E.