go Notices of Books . [January, 
find in some regions — those, to wit, from which the pole is re- 
ceding — a gradual improvement of climate, whilst in others, to 
which the pole is approaching, there will be a correspondingly 
progressive deterioration. Upon such changes not merely 
geology, but myth, tradition, and finally authentic history, may 
contribute to throw important lights. From these various 
sources the author concludes that the climate of Northern and 
Eastern Asia is becoming colder, a view in which Mr. Geikie 
seems to concur. The proofs of this increasing refrigeration 
are to be found “ in the comparison between its present and its 
recently-extinCt fauna, as well as in the geographical distribution 
of the animals that remain.” But ethnology contributes evi- 
dence of a similar tendency, which will be perhaps more widely 
understood. Central, Northern, and North-Eastern Asia are 
now but thinly peopled, and are unanimously pronounced by 
travellers as very ill adapted for the support of a dense popula- 
tion ; yet history and tradition represent these now lone and 
silent deserts as being the officina gentium , a very magazine of 
nations, from which horde after horde issued to ravage the fertile 
lands of Southern and Western Asia and of Europe. Historians 
have recorded these successive migrations, which, commencing 
with the attack of the Hiung-nu upon China, some six or seven 
centuries before our era, culminated in the overthrow of the 
Roman Empire, and lasted down to comparatively modern times. 
But the cause which set these tribes in motion from their original 
seats has been overlooked. According to our author it was the 
commencement of that process of refrigeration and desiccation 
which has evidently prevailed for a long time in Central Asia. 
He contends that at a still earlier period a vast mediterranean 
stretched from the Black Sea eastwards towards the Pacific, 
cutting off the southern parts of Asia from the North. Of this 
sea the Caspian and Lakes Aral and Baikal are now the principal 
remains. By a gradual upheaval this sea was drained, except 
the portions just mentioned. Its former bottom is characterised 
by the “ loess ” formation, more largely developed in East Asia 
than in any other part of the world, and which strongly resembles 
the ooze dredged up by the Staff of the Challenger Expedition 
from depths of about 2000 fathoms. To counterbalance this 
great upheaval of so extensive a portion of the earth’s crust, the 
author considers that the continent of “ Lemuria,” formerly ex- 
tending across the Indian Ocean, was simultaneously depressed. 
A remarkable argument for the former existence of a Central 
Asian Sea is founded on the presence of seals in the Caspian, in 
Lake Aral (till very recently), and in Lake Baikal. The latter 
case is the most important, since in no other part of the world 
do seals inhabit fresh water. Now if we suppose that these 
lakes were formerly parts of an inland sea, it is very conceivable 
that seals might be prevented by the upheaval of the land from 
making their escape to the ocean, and might in successive 
