A STUDY IN ENDEMISM. 273 



districts of Ceylon, and it is obvious that their existence here 

 must depend on an atmosphere often heavily charged with 

 moisture. The complete isolation of this summit causes it to 

 be frequently surrounded with and bathed in mist, especially 

 during the south-west monsoon, which is a time of drought 

 over the country below. It is indeed striking evidence of this 

 to observe that, at this comparatively low elevation, the 

 branches of the stunted trees are draped with pendent masses 

 of Meteorium moss and lichens, like those on our high moun- 

 tains.* " 



To myself, as a student of geographical distribution, the 

 interest of this flora rather lies in the question of how it got 

 there. Ritigala is a fine three-peaked narrow ridge, several 

 miles long, running north and south, and separated by about 

 36 or 40 miles from any equally lofty summits to the south, 

 in which direction alone do other high mountains lie. It lies 

 well in the centre of the " dry " zone of north Ceylon, and it 

 is fairly evident from the general configuration and climatology 

 of Ceylon that these 40 miles, or at any rate the more northern 

 25 of them, must always have been " dry " country, i.e., that 

 they must always have had their rain mainly in the north-east 

 monsoon from September to December, and have remained 

 almost rainless for the rest of the year. The mountains to the 

 south being very old, and the monsoons having blown as at 

 present for a vast period, it is evident that this must be the 

 case. There are damp spots round the tanks or great irrigation 

 lakes that irrigate these regions, and under the bunds or dams 

 that hold up their waters one finds occasional patches of a 

 vegetation more resembling that of the low-country of south- 

 west Ceylon, but nowhere does one find any trace of the plants 

 of the mountain regions. 



As there was of course the possibility that Ritigala might 

 have comparatively recently risen, or have been lowered, 

 I referred to Dr. A. K. Coomaraswamy, the Director of the 



* The remainder of the paper is an enumeration of the plants found, 

 which is incorporated below with the list in this paper. 



