348 
DARWINISM 
CHAP. 
land. 1 Madagascar is the only island on the globe with a fairly 
rich mammalian fauna which is separated from a continent by 
a depth greater than a thousand fathoms ; and no other island 
presents so many peculiarities in these animals, or has pre¬ 
served so many lowly organised and archaic forms. The 
exceptional character of its productions agrees exactly with its 
exceptional isolation 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 is 
perfectly continental. There is also much evidence that it 
does possess one mammal, although no specimens have been 
yet obtained. 2 Its reptiles and birds are highly peculiar and 
more numerous than in any truly oceanic island. Now the 
sea which directly separates New Zealand from Australia is 
more than 2000 fathoms deep, but in a north-west direction 
there is an extensive bank under 1000 fathoms, extending to 
and including Lord Howe’s Island, while north of this are 
other banks of the same depth, approaching towards a sub¬ 
marine extension of Queensland on the one hand, and New 
Caledonia on the other, and altogether suggestive of a land 
union with Australia at some very remote period. Now the 
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 exceptional 
depth of the dividing sea and the form of the ocean bottom 
according well with the altogether exceptional isolation of 
New 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 approxi¬ 
mately how far beyond their present limits our continents may 
1 For a full account of the peculiarities of the Madagascar fauna, see my 
Island Life, chap. xix. 
- See Island Life, p. 446, and the whole of chaps, xxi. xxii. More 
recent soundings have shown that the Map at p. 443, as well as that of the 
Madagascar group at p. 387, are erroneous, the ocean around Norfolk Island 
and in the Straits of Mozambique being more than 1000 fathoms deep. 
The general argument is, however, unaffected. 
