— 118 — 



Another illustration may be given from Ak-jar on the 

 left river-bank, where the thickets attain a width of about 

 70 metres. Nearest the river the thicket consists of Erianthus 

 Rauennae, intei-spersed with Halimodendron argenteum. The 

 latter extends farther inland than Erianthus, and towards the 

 desert it becomes intermingled with Tamarix laxa; this plant 

 is absent from the outer part of the thicket nearest the river 

 but forms the whole of the inland half, growing as scattered 

 bushes about 2 metres high and interspersed with Alhagi 

 Camelorum. Alhagi also extends into the desert, or one might 

 say that it passes from the desert into the thickets, for, al- 

 though never seen in the most barren desert, it must be 

 regarded as a true desert plant. This is also the case with 

 Halostachys caspica, it may be strongly developed in the 

 thickets, but it is especially widespread in the salt -desert 

 (see p. 113). Zygophyllum Eichwaldii, Lycium turcomannicum and 

 Halimodendron argenteum are occasionally desert plants con- 

 fined to clay soils, but in my opinion they are moi'e exacting 

 in their demands and belong to more favourable habitats 

 such as the riverside thickets. 



The plants which are more definitely restricted to the 

 river banks are: Erianthus, Saccharum, Calamagrostis, the 

 poplars, the willows and Elaeagnus, with the addition of the 

 marsh-plants. A few of these, however, occasionally migrate 

 from the river- banks, thus I have seen a weakly form of 

 Phragmites with short aerial runners, along with Calamagrostis 

 pseudophragmites on a slightly saline plain near Chodsheli; 

 the occurrence of Populus pruinosa in the desert is des- 

 cribed in chapter 11. 



In conclusion we give a translation of Antonow's descrip- 

 tion of the transition from the thickets towards the deserts 

 (1. c. p. 189): 



"These thickets quickly become more stunted and poorer 

 at each step we take from the river towards the loess-plain. 

 Only a few Sashen i) from the river, the bush-forms of 

 Chenopodiaceae put in an appearance comparatively well- 



') 1 SacWn (fathom) = about 2,i8 metres = 3 Arshin. 1 Verst 

 about 1067 metres = 500 Sashen. 



