110 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 
Moreover, these 16 land-birds constitute no less than 10 peculiar 
genera, and even one peculiar family of five genera. This isan amount 
of peculiarity far exceeding that of any other islands, and, of course, 
corresponds with the great isolation of this archipelago. The only 
other animals which have here been carefully studied are the land- 
shells, and these tell the same story as the birds. For there are no less 
than 400 species which are all, without any exception, peculiar; while 
about three-quarters of them go to constitute peculiar genera. 
Again, of the plants, 620 species are believed to be endemic; and of 
these 377 are peculiar, yielding no less than 39 peculiar genera. 
THE FAUNA OF MADAGASCAR AND NEW ZEALAND*™ 
A. R. WALLACE 
The two exceptions just referred to are Madagascar and New 
Zealand, and all the evidence goes to show that in these cases the land 
connection with the nearest continental area was very remote in time. 
The extraordinary isolation of the productions of Madagascar—almost 
all the most characteristic forms of mammalia, birds, and reptiles of 
Africa being absent from it—renders it certain that it must have been 
separated from that continent very early in the Tertiary, if not as far 
back as the latter part of the Secondary period; and this extreme 
antiquity is indicated by a depth of considerably more than a thousand 
fathoms in the Mozambique Channel, though this deep portion is less 
than a hundred miles wide between the Comoro Islands and the main- 
land. 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 preserved so many lowly 
organised and archaic forms. The exceptional character of its pro- 
ductions 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 conti- 
nental. There is also much evidence that it does possess one mammal, 
although no specimens have been yet obtained. 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 2,000 fathoms deep, but in a north-west direc- 
* From A. R. Wallace, Darwinism (copyright 1889). Used by special permis- 
sion of the publishers, The Macmillan Company. 
