988 
from the following quotation from Geikie’s 
‘Ice Age’ in the chapter on Asia : 
‘‘Tmmense sheets and terraces of loess fringe 
the alpine lands and sweep outwards upon the 
low grounds of Turkestan and Siberia, but do 
not seem to go much farther north than 54° 
N. L. These, as Kropotkin shows, present the 
same character as the similar accumulations of 
Europe, and haye yielded remains of mammoth, 
rhinoceros, etc., and land shells. In Northern 
China the same accumulation is developed on a 
yet grander scale—covering enormous areas, 
and occurring at all altitudes from a few feet to 
upwards of 8,000 feet above the sea. The dis- 
tribution of the Asiatic loess, its general char- 
acter, and the nature of its organic remains 
hardly allow us to doubt that it has been formed 
under the same conditions as the similar de- 
posits in Europe. Its materials, we may be- 
lieve, are largely of fluvio-glacial origin, and 
represent in great measure the flood-loams 
swept down from the mountains and plateaus 
when these supported extensive snow fields and 
glaciers. But, as Baron Richthofen in his great 
work on China has demonstrated, the loess, as 
we now see it, owes its structure and heaping- 
up to the action of the wind, and is even now 
forming and accumulating in many regions of 
Asia. It is, in short, a true steppe formation.”’ 
(Geikie’s ‘Great Ice Age,’ p. 699.) 
In discussing the origin of the loess, Dr. 
. Wright omits all direct reference to the familiar 
interpretation sketched by Geikie and held by 
many geologists on both continents, and thus 
adroitly creates the impression that the ques 
tion of its deposition lies solely between the 
work of the wind and the work of the sea. 
The following extract embraces the essential 
part of the statement : . 
“Twenty-five or thirty years ago Baron 
Richthofen endeavored to make out that the 
loess was a wind deposit; and certainly he 
found much in Northeastern China to support 
this theory. Upon returning from our trip to 
the Mongolian frontier, we were inclined to 
accept it, for we had seen and experienced, in 
the dust-storms encountered, enough to make 
_us attribute almost anything to the power of 
wind. For a whole day we once rode in a 
cloud of dust so dense that it was impossible 
SCIENCE. 
[N.S. Vou. XIII. No. 338. 
to see objects twenty feet away ; while every- 
where in the mountain valleys we saw in- 
stances where this loess had drifted into pro- 
tected places, as snow does in winter. But 
there were constantly appearing other things 
which were difficult to explain by the action 
of wind. For example, the loess was occa- 
sionally spread out, even at high levels, in 
broad, lakelike basins, as if deposited by water. 
Also the material now most blown about by 
the wind is coarse sand, which is piled up in 
dunes quite unlike the ordinary loess deposits. 
In one instance we found high walls of a large 
Chinese city completely buried on one side by 
a wind deposit ; but this was coarse sand, and 
not loess. In many cases, also, we found long 
lines of gravel and pebbles interstratified with 
loess. Thus the difficulties of explaining every- 
thing by wind so increased that they became 
well-nigh insuperable. 
“But, on coming around to the northwestern 
side of the great Asiatic plateau, in Turkestan, 
which is almost the exact center of the con- 
tinent, the wind hypothesis became entirely 
incredible, and the evidence accumulated that 
the land had lately been depressed to such an 
extent that the water of the ocean reached the 
base of the bordering mountains, rising to a 
height, certainly, of about 3,000 feet; for, at 
this level, south and southwest of Lake Balk- 
ash, we found the loess spread out in such an 
extensive terrace that the wind would be en- 
tirely incompetent to produce the results. * * 
“Tn confirmation of this theory of a recent 
extensive depression of Central Asia, a number 
of other most interesting facts present them- 
selves, prominent among which are those con- 
cerning Lake Baikal. * * * A most curious 
fact, long known to scientific men, is that this 
lake is occupied by a species of seal almost 
identical with those found in the Arctic Ocean. 
The same species with slight variations are 
also found in the Caspian Sea, but not any- 
where else along the 3,000 or 4,000 miles which 
separate these bodies of water. The most prob- 
able explanation of this fact, and the one 
usually accepted by scientific men, is, that 
these species of seal were thus widely dis- 
tributed during a continental subsidence in 
which all the waters of the Arctic Ocean 
