226 Darwin, and after Darwin. 
to cross those distances of ocean: consequently. there 
is only one instance of a peculiar species of bird or 
bat—namely, a bull-finch in the Azores, which, being a 
small land-bird, is not likely ever to have had any 
other visitors from its original parent species coming 
over from Europe to keep up the original breed. 
Lastly, it is very much more easy for insects and 
land-mollusca to be conveyed to such islands by wind 
and floating timber than itis for terrestrial mammals, 
or even than it is for small birds and bats; but yet 
such means of transit are not sufficiently sure to admit 
of much recruiting from the mainland for the purpose 
of keeping up the specific types. Consequently, the 
insects and the land-shells present a much greater 
proportion of peculiar species—namely, one half and 
one fourth of the land-shells in the one case, and 
one eighth of the beetles in the other. All these 
correlations, I say, are abundantly intelligible on the 
theory of evolution; but who shall explain, on the 
opposite theory, why orders of beetles and land-mol- 
lusca should have been chosen from among all other 
animals for such superabundant creation on oceanic 
islands, so that in the Azores alone we find no less 
than 32 of the one and i4 of the other? And, in this 
connexion, I may again allude to the peculiar species 
of beetles in the island of Madeira. Here there are 
an enormous number of peculiar species, though they 
are nearly all related to, or included under the same 
genera as, beetles on the neighbouring continent. 
Now, as we have previously seen, no less than 
200 of these species have lost the use of their 
wings. Evolutionists explain this remarkable fact 
by their general laws of degeneration under disuse, 
