134 COURTS WITH OR WITHOUT LAKE-BASINS. 



that of glacial action, which does not exist there at 

 present ; and the cooses then formed ought to be much 

 more extensive, and bounded with higher cliffs, than 

 those being excavated in the temperate zone at the 

 present day. We would suggest that the corrys, after 

 having been in part excavated by marine denudation, 

 were elevated by the rising of the land out of the 

 influence of its action, and that afterwards they were 

 enveloped in snow and ice, and thereby preserved from 

 "being modified by ordinary meteoric abrasion. Dur- 

 ing the glacial period, all of these corrys, at no matter 

 what level, were protected by this envelope against 

 atmospheric influences ; but as the climate changed, 

 those on low ground, especially if exposed to warm 

 winds or the sun's rays, would be subjected to all the 

 vicissitudes of the atmosphere, which probably altered 

 and modified their forms, or even obliterated them ; 

 consequently, while corrys and cooms are numerous 

 in high lands, in the adjoining low lands only traces 

 of them can be detected. 



In the northern hemisphere the warm winds and 

 sun's rays would act more on the south and west 

 slopes of the hills than elsewhere ; consequently, on 

 the north and east slopes the snow and ice would 

 remain, preserving the cooms, corrys, and cliffs long 

 after the south and west sides had been modified and 

 formed into more or less regular slopes by meteoric 

 abrasion. That such took place in Ireland is quite 



