GEOGRAPHICAL BOTANY. 371 



fills up the bottom of the valley. Jacquemont says 

 (ii, p. 130), "the vegetation which covers the inclined 

 soil is as uniform as this conformation. Variety of 

 localities causes a region to abound in plants, but here 

 all the localities are alike." In the upper regions the 

 forests are generally thin, and belong principally to the 

 valleys. On viewing from a distance one of these im- 

 mense declivities, on which there are scarcely any forests, 

 we perceive lines of a darker green accompanying the few 

 rivulets which water the mountain-slopes, at great dis- 

 tances apart. Between them the green is uniformly 

 pale, for neither meadows nor mountain-pastures thrive 

 there ; but, with the exception of the summits of the rocks, 

 an irregular and unfruitful growth of plants prevails 

 among the blocks and the crumbled portions of rocks. 

 High mountains occur, which, from the valleys to the 

 crests, are covered with this mixture of rocks and plants 

 only. More commonly a thin forest is distributed over 

 a soil of this kind, between 6000' and 7500', consisting 

 either of pine trees on the southern declivities, or the 

 oak, with Rhododendron arboreum, on those which are 

 colder. It is only at the foot of the mountains that dense 

 forests, such as those on the Alps, flourish. The elevated 

 forests of the Coniferous region of the Alps are not met 

 with on the Himalayas. 



At Massuri, Jacquemont measured the lower limit of 

 the oak forest containing Rhododendron arboreum, and esti- 

 mated it at 1768 m. (ii, p. 52). This measurement is 

 tolerably near that given by Royle, who, in this district, 

 determined the elevation of 5 000' to be the level at which 

 the forms of the European forests appear in the place of 

 tropical trees. In his ascent of the Kedarkanta, in the 

 district of the source of the Jumna, Jacquemont also 

 estimated the upper tree-limit at 3500 m. (ii, p. 127). 

 The pine forests (species of Abies) terminated here, and 

 were succeeded by a shrubby formation of Rhododendron 

 (probably Eh. lepidotum Wall.) ; where this also disappears, 

 the alpine soil is covered with turf, consisting of Grasses 



