244 
ISLAND LIFE. 
[part II. 
There is another reason for the very slight amount of pecu- 
liarity presented by the fauna of the Azores as compared with 
many other oceanic islands, dependent on its comparatively 
recent origin. The islands themselves may be of considerable 
antiquity, since a few small deposits, believed to be of Miocene 
age, have been found on them, but there can be little doubt 
that their present fauna, at all events as concerns the birds, 
had its origin since the date of the last glacial epoch. Even 
now icebergs reach the latitude of the Azores only a little to 
the westward, and when we consider the proofs of extensive 
ice-action in North America and Europe, we can hardly doubt 
that these islands were at that time surrounded with pack-ice, 
while their own mountains, reaching 7,600 feet high in Pico, 
would almost certainly have been covered with perpetual snow 
and have sent down glaciers to the sea. They might then 
have had a climate almost as bad as that now endured by the 
Prince Edward Islands in the southern hemisphere, nearly ten 
degrees farther from the equator, where there are no land-birds 
whatever, although the distance from Africa is not much greater 
than that of the Azores from Europe, while the vegetation is 
limited to a few alpine plants and mosses. This recent origin 
of the birds accounts in a great measure for their identity with 
those of Europe, because, whatever change has occurred must 
have been effected in the islands themselves, and in a time limited 
to that which has elapsed since the glacial epoch passed away. 
Insects of the Azores . — Having thus found no difficulty in ac- 
counting for the peculiarities presented by the birds of these 
islands, we have only to see how far the same general principles 
will apply to the insects and land-shells. The butterflies, 
moths, and hymenoptera, are few in number, and almost all 
seem to be common European species, whose* presence is 
explained by the same causes as those which have introduced 
the birds. Beetles, however, are more numerous, and have been 
better studied, and these present some features of interest. The 
total number of species yet known is 212, of which 175 are 
European ; but out of these 101 are believed to have been 
introduced by human agency, leaving seventy-four really 
indigenous. Twenty-three of these indigenous species are not 
