of his argument. "Their very restricted and discontinuous
ranges," he says, "along the extreme western margin of Europe mark them
as decidedly older than those northern animals and plants which have a
circumpolar distribution." We have indeed quite similar examples in the
Oriental migration, of which part is very ancient, surviving here and
there and exhibiting discontinuous distribution. We may therefore look
upon these American immigrants as among the oldest members of that
northern stock which have survived in our islands--probably a mere
remnant of a once luxuriant flora and fauna.

In order to show the importance of the Eastern or Siberian element in
the English, or, we might say with Dr. Sclater, the Anglo-Scotian
mammalian fauna, I herewith give a list of the species of mammals which
probably migrated to Great Britain from Siberia. I have marked with an
asterisk those which still exist in this country (not in Ireland), or
have become extinct within historic times.

Canis lagopus.
Gulo luscus.
* Mustela erminea.
* " putorius.
* " vulgaris.
* Sorex vulgaris.
Lagomys pusillus.
* Castor fiber.
Spermophilus Eversmanni.
" erythrogenoides.
* Mus minutus.
* Arvicola agrestis.
* " amphibius.
" arvalis.
* " glareolus.
" gregalis.
" ratticeps.
Equus caballus.
Saiga tartarica.
Ovibos moschatus.
Cricetus songarus.
Myodes lemmus.
Cuniculus torquatus.
Alces latifrons.
" machlis.
Rangifer tarandus.

We have evidence that most of these twenty-six species of mammals came
from Eastern Europe, but there is no reason to suppose that they
originated there. On the contrary, it is highly probable, as I said
before, that their native home is Siberia, and that they entered Europe
to the north of the Caspian. Along with these, vast numbers of other
forms of life, and also plants, swarmed into our continent, and as we
advance eastward from England we meet with them in increasing numbers to
the present day. But not only on the Continent do we find these
survivals of the great Siberian migration, which has been so ably
described by Professor Nehring; no less than nine species still inhabit
Great Britain (if we include the recently extinct Beaver). On the other
hand, not more than three have been found fossil in Ireland, and of
these only one still survives. This very significan