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Show 348 DARWINISM CUAl'. land. 1 Madagascar is the only island on the globe with a hirly rich mammalian f~tuna. which is separated from a continent hy a depth greater than a thousand fathoms ; and no other island presents so many peculiarities in these animals, or has preserved so many lowly organised and archaic forms. The exceptional chara,cter of its productions agrees exactly with itR exceptional isola.tion by means of a very deep arm of the sea. New Zealand possesses no known mammals and only a single species of batrachian ; but its geological structure iR perfectly continental. There is also much evidence that it does possess one mammal, although no specimens have hcen yet obtained. 2 Its reptiles and birds arc highly peculin,r and more numerous th:tn in any truly oceanic island. Now the sen, which directly separates New Zealand from Australia i-; more than 2000 fathoms deep, but in a north-west direction there is an extensive bank under 1000 fathoms, exten<ling tl) and including Lord Howe's Island, while north of this arc other banks of the same depth, appro:tching towards ~t RnlJmarine extension of Queensland on the one hand, and ew (;tdedonia, on the other, and altogether sugge tive of a land union wit:t Australia at some very remote period. Now Uw peculiar relations of the New Zealand fauna and flora with those of Australia and of the tropical Pacific Islands to the northward indicate such a connection, probably during the Cretaceous period; and here, again, we have the exceptiollal depth of the dividing sea and the form of the ocean bottom according well with the altogether exceptional isolation of N cw Zealand, an isolation which has been held by some naturalists to be great enough to justify its claim to be one of the primary Zoological Regions. The Teachings of the Thousand-Fathom Line. If now we accept the annexed. map as showing us approximately how far beyond their present limits our continents may 1 For a full account of the peculiarities of the Madaga car fau na, f;Ce my Jslanr/, Life, chap. xix. 2 See Island L~fe, p. 446, and the whole of chaps. xxi. xx ii. More recent soundings have shown that the Map at p. 443, as well as that of t he Madagascar group at p. 387, are erroneous, the ocean around Norfolk hl:u11l and in the Straits of Mozambique being more than 1000 fathoms Jeep. The general argument is, however, unafl'ected. |