ng at present. Ruetimeyer long ago
remarked that it seemed to him much more probable that Morocco, Algeria,
and Tunis were peopled by way of Gibraltar, and perhaps also by Sicily
and Malta from Europe, than Southern Europe from Africa. After careful
conchological researches in the Western Mediterranean region, Dr. Kobelt
came to the conclusion that formerly Southern Spain and Morocco must
have been united by a broad land-connection. Sicily and Algeria do not
apparently show any very intimate relationship conchologically, but
farther west--in the mountains of Tetuan--Dr. Kobelt discovered a colony
of Sicilian forms.[3]

"The close relationship," remarks Dr. Major (_a_, p. 106), "shown in
the fauna of Corsica and Sardinia to Africa, permits the supposition
that the connection with these islands had persisted to a much more
recent date than that with Europe."

Many other authors have pointed out the close similarity existing
between the faunas of Southern Europe and North Africa. We need only
refer to the writings of Professor Suess, Milne-Edwards, and Boyd
Dawkins. Mr. Blanchard went even so far as to say, "a comparer les
plantes et les animaux de la Sicile et de la Tunesie, on se croirait sur
le meme terrain" (p. 1047).

No less than 113 species of phanerogamic plants are enumerated by
Professor Engler (p. 53) as occurring in the Mediterranean coast region
east and west of Italy without being found in that peninsula, or at
least only in the extreme south of it. But he tells us that these
species represent only a portion of such plants, which are extremely
numerous.

In taking a general survey of these plants, Professor Engler is of
opinion that their range implies that a large number of the
Mediterranean species have migrated along a line which can be drawn
between North Africa, Sicily, Greece, Crete, and Asia Minor, and that
from this line the distribution started northward again.

Many of these plants then, and also some of the animals I have referred
to, formed part of the older stream of migration which entered Europe
from Asia Minor (_vide_ Fig. 5, p. 117). There were only two courses
open to them as they arrived on our continent during earlier Tertiary
times. They could either go straight west towards Greece, or in a more
northward direction to the newly-formed Alps. As the latter were raised,
some of the immigrants were modified so as to adapt themselves to the
new surroundings. Others became extinct; but a