Or THE. SEA AND LAND. 39 



eating the destruction of the surrounding land, and to 

 a depth which, in some places, reaches to six hundred 

 feet ; while the total loss may well be much more, 

 unless we could suppose that the vei-n itself had under- 

 gone no vertical diminution. All these, and more 

 that I might name, indicate that cause which I shall 

 immediately attempt to assign : the following instances 

 are but proofs of that tedious action of the sea which 

 I have already examined. I note them here, for the 

 purpose of teaching young geologists the necessity of 

 attending to causes, in reporting identical appearances. 

 From Loch Craignish northwards, the shore is crowded 

 with them, projecting towards the sea, like huge walls, 

 and sometimes reaching to a hundred feet in height. 

 In Sky and in Mull, they are still more remarkable ; 

 being covered, in the latter island, with ivy, and giving 

 root to shrubs and flowers, so as to resemble those 

 ruins of antient castles which occur in similar situations. 



In some countries, certain tracts appear to have 

 suffered more from this process than others, though 

 no obvious reason can be assigned. Such seems to 

 "be the case in many parts of England ; but that por- 

 tion of Scotland which is included between the Murray 

 firth and that of the Forth, shows it in the most 

 striking manner. The great trap range of the Campsie 

 and the Ochils, begins to show marks of waste as it 

 passes Perth ; while, in advancing further eastward, it 

 gradually vanishes : the marks of its former extent 

 remaining, in the indications already mentioned, as far 

 as Stonehaven and Montrose. Thus also, in Aberdeen- 

 shire, the stratified rocks are removed down to the 

 surface of the granite ; as if this part of the island had 

 been exposed to some causes of destruction from which 

 the western was exempted. 



If I need not illustrate this subject of denudation by 



