154 MOUNTAIN AND MOORLAND 



occurs also on the banks of the stream : there is 

 gouging and undermining and falling in and sweeping 

 away; and this has been going on for ages. Of course 

 there are more violent ways of deepening and broaden- 

 ing the bed days of flood notably, when ail the stones 

 seem up in arms. 



When we were walking one day with an old 

 naturalist up the side of the river not this little 

 mountain stream he pointed to an island covered 

 with small Alder-trees and said : " I lave seen the 

 whole of that island made." It was ii the lee of a 

 large island, and our friend had wtnessed in the 

 course of forty years the gradual accumulation of 

 sand and gravel in the sheltered area where the water 

 flowed slowly. Probably the smaller island was for 

 a time only a downstream promontory of the larger 

 one, and then a peninsula, and fnally independent. 

 We meant to have asked, but the ld naturalist began 

 to say something about a Kingfoher, and we forgot 

 about physiography. 



In many parts of the countn we may see what is 

 called "crag and tail." A high boss of hard rock has 

 been surrounded by a glacie which gouged out a 

 deep hollow in front of the obstacle and on each side, 

 but left in the protected lee ; long slope or tail. The 

 glaciers have passed away, fat their handiwork is seen 

 in "crag and tail." And its very interesting to look 

 in the bed of the stream or the same sort of thing, 

 only on a very small sc?e, and with a swift flow of 

 water instead of an imerceptible flow of ice. We 

 see a firmly fixed hard jtone > at the upstream end of 

 which there is a deep e cavation, while at the sheltered 

 downstream end the- is a sloping "tail" of sand. 



