CHANNELS AND GLENS OF AYRSHIRE. 63 



Ate* friM # eds 



App Water. — The App, owing to its running between high 

 steep-sided hills, has not left the old valley in scooping out the 

 drift-beds, except towards the very head of the glen, where the 

 burn turns suddenly, leaving the boulder-clay, and runs on rock, 

 the old valley of the App at this part being still filled with drift, 

 covered by peat. 



A number of the streams, as the Afton, Craig's Burn, Polgown, 

 Pundeavon, Pitcon, Routenburn, Powgreen, Potian, Burn Anne, 

 and others, cut through rock probably in the bottoms of the old 

 glens, or sideways from them ; though some of them may have 

 old glens placed at some distance from the new ones. 



Hollows at the bases of the hills. — A number of the Ayrshire 

 rivers have considerable hollows at the bases of the hills, as for 

 instance the Powgreen at the base of Cuff Hill, the Garnock 

 above the falls, the Afton at Montraw, the Gass Water at the 

 base of Wardlaw, the Nith near Waterhead, the Girvan at Loch 

 Bradan, the Bottom at the base of Blackcraig, the Tig below 

 Strawarren Fell, the Clocklowie at the base of Clocklowie Hill, 

 the Haw near Laggish (the hollow), the Deugh above Glenenlee, 

 and others ; and at the north and north-east bases of Corsincone 

 there are deep hollows — the culminating feature in this respect 

 being the hollow in which Loch Doon is situated. 



These hollows have certainly never been formed by the rivers, 

 and have possibly been made by the joint action of the streams, 

 the first glacier-ice and the sea, and subsequently received their 

 present forms by glacier-ice, as we clearly see by the manner in 

 which Loch Doon's rocky shores are moutonnee and striated. Some 

 of them, as Loch Doon, may be due to subsidence. 



Positions of the post-glacial glens. — The positions of the rocky 

 post-glacial glens, in a marked degree, depend on the formations 



