LIVERWORTS IN THE WESTERN HIMALAYAS. 151 



pass. The Inner Himalayas have been crossed only at one 

 place, the Baralacha pass (16,200 ft.). The country beyond that 

 has been visited for about twenty miles up to Lingti Sumdo but the 

 climatic conditions on that side are so uniform over large areas that 

 nothing new would probably be found even much further inwards. 

 The minimum elevation of this region ia 14,000 ft. In all cases the forms 

 collected most were from the road-side along the rivers at different 

 levels and at various levels during the crossing of the ranges though 

 short excursions were also often made away from the main road. 



General Results. 



The more important general conclusions may be stated briefly 

 as follows : — 



Most of the species found in the Western Himalayas are thallose. 



In the Outer Himalayas the number of species found at a given 

 altitude decreases in proceeding from the eastern end to the west. 

 This decrease is very much more marked if we take into consideration 

 the number of individuals. (Vide lists of species at the end.) 



As regards vertical distribution, the number increases up to a 

 certain height in going from the plains. The number in the plains is 

 very small. It increases up to about 7,000 ft. and begins to decrease 

 again after that. This applies also to the number of individuals. 

 (Vide lists of species at the end.) 



On the northern side of the Outer range the same law holds good 

 but the number of species and individuals is much smaller. Thallose 

 forms are chiefly found only near springs. In other places they are 

 as a rule absent. 



The horizontal distribution in the Ravi valley probably follows 

 the rule given above but the data are too few to admit of a definite 

 statement being made. (Vide list.) 



On the southern side of the Middle Himalayas the number is 

 even smaller than on the northern side of the Outer range, and it 

 decreases as we go up. 



In the Chandrabhaga valley it can be definitely stated that the 

 number decreases as we go down the river. The number on both 

 sides of the river is very small, but of the two the left bank, i.e., the 

 northern slope of the Middle range is comparatively richer. Pangi is 

 the only part where any foliose forms have been met with. They are 

 absent both to the east and west of it. 



The initial level of this valley is very high, being above 8,000 

 ft. in the Chamba territory. The largest number of individuals is 

 met with between 8,000 and -9,000 ft. in Pangi and up to 11,000 ft. 

 in British Lahoul. The explanation of this difference no doubt lies 



