- 
a) = 
northern part of this is a Stipa-steppe which I prefer to omit, 
as I have not seen it, and it does not occur farther south. 
The southern part is a desert in the sense employed in this 
memoir, (see chap. 5) with its northern boundary, according 
to TANFILJEW, (1903, pp. 386, 388) extending from the southern 
end of the Mugodshar Mts. to the town of Uralsk, and 
which, in a more or less changed form (the “Kalmyk Steppe’’) 
extends westwards to the foot of the Jergeni Mts.') But this 
northern desert must be far less warm or less dry (perhaps 
both) than the deserts south of the Aral Sea. We are led to 
this conclusion because Hippophaé rhamnoides, Salix repens, 
Koeleria glauca, Elymus arenarius, Populus tremula, Amygda- 
lus nana, Rhamnus catharlica and several other plants (see 
SAWITSH p. 224) occur here near their southern limit on the 
plain, although several of them e. g. Hippophaé and Amygda- 
lus are again found in the mountains to the south (Compare 
Borszczow cited later p. 29, point 1,3) The list of plants 
given later (chap. 12) would convey a less striking picture 
of the character of the desert if these plants were included 
in it, and for this reason I have excluded the Kirghiz Steppe; 
moreover, as already stated, the expedition did not explore it. 
What name then can be given to the territory, delineated 
as above, and whose vegetation is the subject of our memoir? 
The area from the Caspian Sea and far into China is 
generally designated “Turkestan” and, even if in accordance 
with MusHKETOw, we limit it to the lowlands west and north 
of the mountains, it will still include the Balchash Basin and 
the Kirghiz Steppe which we wish to exclude. The same 
7”) According to BEKÉTOFF (1886) and ParscHoskis (1892) the Jergeni 
Mts. form the boundary between European and Asiatic vegetation, the 
former is the steppe of southern Russia, for the most part under cultiva- 
tion, the latter is a desert, the «Aralocaspian steppe», as PATSCHOSKIJ terms 
it. According to RAppE (1899), the Jergeni forms the boundary between 
better humus soil (4—7 per ct.) towards the west and poor humus soil 
(under 2 per ct.) towards the east. Finally, according to WOoEIKoFF (Hann 
III p. 194) the Jergeni Mts. coincide with part of the eastern limit of Rus- 
sia’s regular summer rains, which is evidently the cause underlying the 
contrast between vegetation and soils, 
