, and in the winter time the northern would
swing southwards, and thus occupy at different times of the year the
same tract of ground, as is now the case with the Elks and Reindeer."
Very different are the views of Professor Nehring on this subject.
According to him, the climate in Germany must have been extremely cold
and damp, resembling that of Greenland, though perhaps not quite so
arctic. Professor Nehring does not at all believe that southern and
northern species of mammals could have lived in Central or Northern
Europe at the same time; though of this we have undoubted geological
evidence (pp. 72-75). He thinks that the supposed commingling of
southern and northern types, which has actually been shown by Professor
Dawkins to occur, is either due to careless observation or to the fact
that some of the species need not necessarily have lived where their
bones were found (p. 133).

The most reliable conclusions as regards former conditions of vegetation
and climate can be drawn, according to Professor Nehring, from the
smaller burrowing mammals, such as the marmots, sousliks, etc. He is of
opinion that a great portion of Northern Europe, where their remains
have been discovered, must have possessed tundras and steppes, as we
find them nowadays in Siberia, and a climate similar to that of Northern
Asia. It is presumed that the climate, after the maximum cold of the
first stage of the Ice-Age, ameliorated so far as to permit these
mammals to exist in Europe.

The natural question, however, which is forced upon us in reading
Professor Nehring's interesting and suggestive work is, where did all
these steppe animals live during the earlier part of the Ice-Age? No
traces of their remains have been discovered in Southern Europe, and it
can therefore certainly be affirmed that they could not have lived
there. If Central and Northern Europe were uninhabitable for mammals,
Central and Northern Asia must have been even more so, and we have to
fall back upon the Oriental Region as a possible home of these species
during the assumed maximum cold of the Glacial period. In invading
Europe from the Oriental Region these Siberian mammals would have taken
the shorter route by Asia Minor and Greece, which was open to them. This
they certainly did not do, which proves that they came directly from
Siberia to Europe without retreating first to Southern Asia.

But it seems to me that there is no necessity for assuming such drastic
chan