re now being studied with a view to
determining their exact range in these islands. Mr. Harvie-Brown, Mr. J.
W. Taylor, Mr. Eagle Clarke, Mr. Miller Christy, Mr. Ussher, Mr.
Barrington, and a number of others have considerably advanced our
knowledge in this direction in recent years.

Any such contributions are to be welcomed as furnishing us with the
necessary data to solve the problem of the origin of the British fauna.
Meanwhile we know enough to enable us to assert positively that the
latter has reached us by land-connections from various parts of Europe
(cf. p. 35). This statement of course refers to the bulk of the British
fauna. The small proportion of indigenous species, or such as have been
introduced accidentally, may be left out of consideration when dealing
with the great mass of animals which have evidently migrated to the
British Islands on land now sunk beneath the sea (see Fig. 4, p. 60).
Opinions of zoologists, botanists, and geologists are practically
unanimous on this subject; yet there are two other theories, which have
from time to time been advanced to account for the origin of the British
fauna. Only the first of these, however, can claim the serious attention
of those interested in the problem. Its chief contention lies in the
oft-asserted dictum of the "_imperfection of geological record_." It has
been suggested, in fact, that the British fauna, instead of having
migrated to our islands, might have originated there, but that, owing
to the fragmentary nature of our Tertiary deposits, all trace of their
early history had disappeared. "The origin of European species," remarks
Professor Cole (p. 238), "within the area of the British Isles, and
their migration outwards when local conditions became less favourable
for their multiplication, are possibilities that seem too often
disregarded. Yet the geologist must see in the western borderland of
modern Europe a diminished continent from which land-animals must have
again and again moved eastward." "Hence geologists may fairly be
unwilling to look on our isles as barren lands waiting to be peopled in
pliocene or later times. Far rather has the breaking up of a broad
land-area along the present continental edge sent our land-fauna to the
new steppes that opened eastward, leaving us a mere diminished remnant
to struggle with the glacial period."

There are in Professor Cole's views many points with which I readily
agree. In the first place, he acknowledg