370 GEOGRAPHICAL BOTANY. 



the seasons ceases, and the dryness of Thibet commences, 

 Jacquemont's botanical observations agree with the more 

 copious reports of Royle. The forests are very incon- 

 siderable, the growth of grass poor, and kept down by 

 Tragacanth-shrubs {Astragali} , which are distributed as 

 far as here; the alpine flora is also very scanty 

 (ii, p. 269). Jacquemont devotes particular attention to 

 the cultivation of the grape-vine, which is confined to 

 this part of the Himalaya, not extending beyond the limits 

 of the tropical rain (ii, pp. 416 et seq.) Although the 

 grape-vine is cultivated at an elevation of 10,000', this 

 is only the case in the bottom of the valley, not on the 

 mountain-slopes, for it only there receives the reflected 

 rays of the sun, which are necessary to ripen the grapes, 

 and there it is also protected from that radiation of heat 

 which exerts too powerful an effect in cooling the earth 

 on mountains. Moreover, even in the valley of the Sutlej, 

 irrigation is indispensable to this branch of culture ; 

 but although the grapes under these circumstances mostly 

 ripen well, they are usually dried in the sun, and used 

 to make raisins, as the wine does not keep long, and 

 even when new was found almost undrinkable by the 

 Frenchman. We find the grape-vine as far upwards as 

 Nako, in the valley of Spiti, and downwards as far as the 

 mouth of the Buspa, where the climatic line above men- 

 tioned lies, and where the Sutlej intersects the high 

 southern chains of the Himalayas. 



The chains of the Southern Himalayas, which are 

 situated immediately opposite to the plain of the north 

 of India, do not possess any of that variation of soil, by 

 means of which their vegetation might equal the flora of 

 the Alps in variety, notwithstanding the mixture of forms 

 of Tropical and European plants. Plane surfaces are 

 scarcely anywhere found; and as we have already re- 

 marked, the broad valleys of Cashmere and Nepaul form 

 exceptions to the mountain-character. Perpendicular 

 precipices are also absent. We find everywhere vast in- 

 clined plains, and the mountain-stream usually entirely 



