87 



and he offers for their solution a vera causa, one certainly capable of 

 producing such appearances. At that time glacial action had not 

 been recognized in these countries ; and he offers the best explanation 

 that could then have been given. The action of ice is, however, 

 more simple, rational, and consistent, not only with these appearances, 

 but with others to be presently mentioned. 



Similar mounds occur, but not in the terraced form, at the open- 

 ings of Glen Sannox and Glen Rosa, much elevated above the river 

 beds. Some way up the latter, also, there are remarkable mounds, 

 in a situation where, from a great bend in the glen, we should expect a 

 moraine to be thrown down. Many other examples might be given ; 

 but it is unnecessary to refer in greater detail to phenomena of this 

 class. A closer examination of the contents of the mounds and ter- 

 races, which are limited to the rocks of each particular glen, has led us 

 to modify the view already expressed (Art. 13) regarding their origin. 

 We admit, however, that the few decided cases of striation, such as 

 are so frequently and distinctly marked in the valleys of the lake 

 district of Cumberland, radiating in all directions from Great Gabel 

 as a centre, or, as are already noticed by us regarding the West of 

 Scotland (Arts. 10-13), goes so far against the glacial theory as appli- 

 cable to Arran, and in favour of the idea that the mounds and 

 terraces in question were formed when currents swept these glens, 

 during the gradual elevation of the land. That such elevation 

 may have been a long continued process we have already seen 

 reason to suppose (Art. 52, 53); and the effect must have been 

 a general disturbance in the sea bed, which, joined to the action 

 of tides produced then as now, could not fail to give rise to 

 currents of considerable force. Where these met the sea towards 

 the mouths of the glens, banks and terraces may have been thrown 

 up ; or a sudden elevation of the land of a cataclysmal character 

 may have given origin to long continued currents of sufficient force 

 to transport large blocks, and to throw down a promiscuous de- 

 posit, such as we find in the mounds and terraces of the mountain 

 glens. Such sudden elevations of a range or group of mountains 

 are still regarded by many geologists as the true explanation of the 

 " diluvial phenomena ;" and it was such probably that Dr. MacCulloch 

 had in view when he spoke, in the passage above quoted, " of other 

 causes, of a transient and probably of a diluvian nature," as giving 

 origin to the remarkable accumulations at the mouths of the Catacol 

 and lorsa. 



59. The dispersed blocks present phenomena still more curious 

 and of much more difficult explanation. They are almost exclusively 



