Introductory. xv 



in the moist region, i.e., the rainfall is nowhere less than 75 in. 

 per annum. In most parts the fall is much greater, and in 

 some localities in the Adam's Peak Range reaches 250 in. or 

 even more, mostly falling during the south-west monsoon, 

 which strikes with full power on the escarpment having that 

 aspect. 



The hill country occupies a large portion of the Central 

 Province and of the Provinces of Uva and Sabaragamuwa, 

 and very small parts of the North-western and Southern 

 Provinces, the whole mountain mass being thus situated 

 S.W. of the centre of Ceylon. It is separable into four 

 blocks : — I. The main block, which lies to the south and is 

 by far the largest, comprising the great extent of hill country 

 extending from Dolosbage on the west to Madulsima on the 

 east, and from Hantane and Maturata on the north to the 

 Adam's Peak Range and Haputale on the south. 2. The 

 north-western block or chain, running northwards, and sepa- 

 rated from or connected with the last by the narrow Kadu- 

 ganawa Pass (1700 ft.). 3. The north-eastern block or chain, 

 isolated from the main block by the Dumbara Valley and 

 Mahaweli River, and from the north-we.stern block by the 

 Matale Valley ; also running northwards. 4. The southem 

 block, much smaller, isolated in the Province of Sabaragamuwa, 

 and forming the district of Rakwane. 



It is convenient to divide this region into a lower and an 

 upper montane zone by the line of 5000 ft. altitude, which is 

 found to form a fairly good lower limit for our more truly 

 montane species {Rhododendron arboreum may be regarded 

 as a good example). Nearly the whole of the upper zone is 

 found in the main mountain block, a little in the north- 

 eastern, but none in the north-western or southern blocks. 

 It chiefly consists of the considerable tracts of table-land 

 known as plains (Nuwara Eliya Plain, about 6200 ft. ; Elk and 

 Horton Plains, over 7000 ft.), and the mountain-tops standing 

 round them. 



