— 270 — 



above, we have that the "northerly" plants include only 9 

 p. cent, which are exclusively northern, the "easterly" ones 

 22 p. cent, exclusively eastern, while the "southerly" plants 

 include 33 p. cent, exclusively distributed towards the South. 



These figures as in the case of the percentage for the 

 total distribution, show that the Transcaspian lowlands are 

 most closely related to the countries lying towards the South 

 and South-West, and most distantly related to the countries 

 lying towards the North. This is the case though the Trans- 

 caspian lowlands towards the North are open and without 

 any natural boundary, while in every direction towards the 

 South they are hemmed in by mountains. 



This result is further confirmed if we take into con- 

 sideration the species which the Transcaspian lowlands have 

 in common with Syria and Palestine (166 species, Post, 

 indicated in the list by V*), or with Egypt (91 species, 

 AscHERSON & Schweinfurth) ; that is respectively 22 and 12 

 p. cent, of the total number of species. About one-third of 

 these (Syria 30, Egypt 29 p. cent.) do not occur either east 

 or north of Transcaspia, and less than half of them (Syria 

 39, Egypt 41 p. cent.) are widely distributed species which 

 are also found north and east of Transcaspia. 



Compare with this what has been stated about species 

 common to Yekaterinoslaw and to Pamir. Here almost all 

 the species in common have a wide distribution; this com- 

 munity therefore indicates a more distant relationship than 

 that between areas with species in common which show a 

 more limited distribution. 



Though derived from imperfect and somewhat scanty 

 materials, our figures point in the right direction, as they 

 have shewn us that the Transcaspian lowlands in their flor- 

 istic as well as their biological aspects (comp. above p. 160) 

 are more closely related to the countries towards the South. 

 This result will probably be further confirmed by future 

 systematic investigations within the individual genera or 

 families. Such investigations are already being carried on, 

 and we may illustrate them by a short summary of Professor 

 KusNEZOw's interesting investigations on Rindera Pall., a genus 

 of Borraginaceae. 



