Page:The Journal of Indian Botany.djvu/184

 Bangahal range is given off another range towards the west running more or less parallel to the Middle range. This range is known as the Outer Himalayas. The Middle and the Outer ranges may be said to terminate where the Chandrabhaga and the Eavi respectively pierce them to debouch on the plains. Going up one of the feeders of the Chandrabhaga from Kashtwar one has to cross a range which separates the waters of the Chandrabhaga from those of the Jehlum in order to enter the valley of Kashmir.

A few more facts in connection with the geography of these ranges should be borne in mind before discussing the distribution of any group of plants. The Outer Himalayas have a mean altitude of about 15,000 ft., though some peaks rise up to 17,000 ft. Most of the hill-stations for summer for the Punjab are situated on this range at an elevation of about 6 — 7,000 ft., as Simla, Dalhousie, Murree, etc. The passes in this range are about 8,000 ft. high. The Middle Himalayas have a mean elevation of about 17,000 ft. though some peaks rise to 19,000 ft. The passes range from 13,000 to 17,000 ft. The inner range has a mean altitude of about 18,000 ft. though some peaks rise to more than 20,000 ft. Passes range from 17,000 to 18,000 ft. in Pangi. The lowest pass is the Zojila in Kashmir, 11,000 ft. The Baralacha in British Lahoul is 16,200 ft.

Area Visited.

The places visited by the writer are sufficiently numerous and different as regards altitude, etc., to provide reasonably reliable data for the study of distribution though naturally there is a great field for more work in this direction as the area under investigation is so large and diversified while the interior is not easily accessible and requires a certain amount of equipment to be explored.

In the Outer Himalayas the writer has visited Simla, Dalhousie* Murree and some other smaller places but the collections from some of the latter (including Murree) are not sufficiently large to draw detailed conclusions though notes as regards the relative numbers of individuals of Liverworts are available. The Beas valley (Kulu) has also been visited. The Outer Himalayas have been crossed at two places to enter the Ravi valley and at one place (Murree) to enter the Jehlum valley. The Middle Himalayas have been crossed at two places at quite a long distance from each other, the Sauch pass (14,300 ft.) leading to Pangi and the Rohtang pass (13,400 ft.) between Kulu and British Lahoul. The Ravi valley has been explored along the river from Chamba to Chhatrari. The Chandrabhaga has been followed from its source to about 200 miles. The Kashmir valley was entered from the Chandrabhaga valley by crossing the Sinthan