40 



full view before him. Moon Plains is approximately a mile 

 long from east to west and half a mile wide. It lies at an altitude 

 of about. 6,500 feet, but is itself of comparatively low relief. 

 From the edge of the patanas on the hills to the rather broad 

 valleys is probably always less than 200 feet, and usually less 

 than 100. However, from the highest end of the patana to the 

 bottom of the canyon which drains it at the other end may be 

 as much as 300 feet. The slopes of the hills lie at a low angle 



Fig. 35. The sharp transition zone between the patana and the mossy forest. 



Ceylon. 



also, so that the whole patana has a gently undulating surface. 

 From one end to the other, hundreds of Rhododendron trees, 

 Rhododendron arboreum, are scattered over it, but always at 

 considerable intervals, so that they can in no case be dignified 

 collectively by the term grove, forest, or thicket. 



Even from a distance one can distinguish by their color the 

 three component associations. One of these, which may be called 

 for convenience the dry grassland, occupies probably 90 per cent 

 of the area. 



The dry grassland association occupies all the hilltops and 

 hillsides from the edge of the forest down nearly to the bottom 

 of the valleys. Throughout, the soil is loose, coarse, and gravelly, 



