— 31 — 



9. When we take into consideration how the sheets 

 of water and the river-systems are drying up ^) while the 

 dryness of the dimate increases, it may almost be regarded 

 as certain that the western and northern forms will ere long 

 cease to reproduce themselves successfully in theAralo-Caspian 

 countries, and that forms already found there will begin 

 to die out. On the other hand, it is beyond doubt that the 

 southern and south-eastern desert-forms will continue to 

 extend their zone towards the north and the west as a 

 result of the environment. Saxaul, Elaeagnus hortensis and 

 some others are at present migrating towards the north, 

 whereas species such as Populus nigra and P. alba are 

 disappearing from the southern latitudes where they occur- 

 red; this proves, that this period is already drawing near." 



BoRszczow's memoir ends with some brief notes on the 

 Cryptogams which, on the whole, are not specially important. 

 Parmelia esculenta occurs sporadically in the deserts along 

 with a few Lijcoperdaceae. 



In spite of its antiquity, Borszczow's work has been 

 dealt with at considerable length because, on the whole, it 

 conveys an interesting picture of the Aralo-Caspian countries. 

 The relation of the flora to that of the surrounding areas is 

 especially well defined, hence I have included the Stipa- 

 steppe, which otherwise does not come within the scope of 

 this work. As far as I know, Borszczow's work is the only 

 one that treats the flora of Aralo-Caspia from that point 

 of view, but it may be that other important works have 

 been overlooked on account of the inaccessibility of Russian 

 literature. 



The next work known to me in this connection is: 

 A. A. Antonow: "On the Plant-formations of the Trans- 

 caspian territory" ') 1892. 



') According to Baer (1855), the phase of drying up is now past and 

 a condition of stability has long ago set in. Comp. Schwarz and Berg, 

 above page 14. 



') "Territory" is here given as the translation for "oblast". In 

 BoRSzczow, ''area" Is given; this author uses it as corresponding to 

 Antonow's "formation." Antonow himself uses the word "formation." 



