[54 DISTRIBUTION AND HABITS OF ARGALI SHEEP 



The difference in habits is little or none. It is therefore 

 not impossible to conclude that they have originated from a 

 common ancestral species. 



Furthermore, it seems to me that the very general 

 opinion that Argali are typical high-mountain animals is not 

 free from objections. From studying their habits it seems 

 fairly established that they, as a rule, avoid wild and craggy 

 rock-districts, unless they have been forced there by cir- 

 cumstances or been driven thither by man. On the 

 contrary, the vast rolling highland plateaux, the wide valleys 

 and the lower, grassy slopes of the mountains seem, their 

 favourite grounds. When they are fully undisturbed we 

 find them sometimes on the steppes or on the borders of the 

 desert. This impression is shared by such explorers as 

 Przhevalsky, Wallace and Carruthers. 



A general study of their habits lead us therefore to 

 believe that the Argali sheep did not originally belong to 

 the mountain animals, but probably inhabited more steppe- 

 like territory, from which they have, by change of climate 

 or other contributory causes, been forced to' seek and 

 accustom themselves to the mountainous regions bordering 

 upon their old grazing grounds. 



The main cause of this migration is undoubtedly the 

 slow but sure process of desiccation and in-sanding which 

 has taken place and still occurs in Central Asia. It is not 

 impossible that this geological change has much to do with 

 the distribution of and character of the wild sheep races in 

 the regions enumerated above. 



Geological and climatological changes in Central Asia. 



According to Baron F. von Eichthofen the desiccation 

 and in-sanding of the regions in question took the following 

 course, which I shall now briefly describe : 



The desert areas which now lie inside the "frame" 

 formed by the various distribution districts of the Argali 

 sheep was during Tertiary time covered by a vast inland-sea, 

 the so-called Han-hai. This sea was connected across the 

 present lake Balkash with the Aralo-Caspian depression, 

 which in its turn stood in connection with the Arctic Ocean. 



During a later epoch but still during the Tertiary the 

 Han-hai was, through intervening rise of land, cut off from 

 above connection and thus came to form a central sea or 

 salt-lake without outgoing drainage. 



Later on, during a drier ^climate, the Han-hai evapo- 

 rated more and more and thus diminished in size until at 



