1873.] GASTALDI — GLACIER-EROSION IN ALPINE VALLE3TS. 401 



formation of these particular lakes had not been answered. It 

 seemed to him that what had been said as to the filling by ice of 

 the valleys with cirques at the sides did not in any way imply that 

 the valleys had been formed by the action of ice. In the case of 

 the Konigsee, the vast precipice at the end seemed especially an 

 instance of a cliff that might have existed in preglacial times. He 

 thought that the author's contention that such precipices could not 

 have been formed by the action of glaciers was substantiated. At 

 the same time he would not maintain that glaciers could not exca- 

 vate basins, but denied their power to excavate deep basins with 

 highly inclined sides. He wished that more attention had been 

 paid to the stratigraphical features of the rocks in which the lakes 

 were excavated. He cited Mr. Kinahan as having stated that the 

 greatest depths of Loch Lomond coincided in position with faults 

 which could be observed in the surrounding country. He differed 

 from Prof. Ramsay as to the preponderance of lakes in regions 

 which have been glaciated, and thought they were more closely 

 connected with the configuration of hilly countries, which was by 

 no means of necessity connected with glacial erosion. 



Prof. Ramsay doubted the completeness of Mr. Kinahan's know- 

 ledge of the structure of a country which had never been thoroughly 

 mapped. As to cliffs surrounding lakes, he by no means thought 

 that they were now in the same condition as when the glaciers 

 retired. Such cliffs were in fact escarpments working back and 

 undergoing constant change. He could not understand any one 

 acquainted with regions that had been glaciated, as, for instance, 

 the northern half of North America, not connecting the prodigious 

 number of lakes that prevailed with the action of the ice which 

 once covered the country. The longer axis of the lakes in many 

 instances coincided with the general direction of the flow of the ice ; 

 and, by itself alone, this circumstance afforded great support to his 

 views. 



Mr. Bonnet, in reply, pointed out that he had never denied that 

 ice might once have occupied the bottoms of cirques, and even have 

 excavated some of the rock-basins. What he wished to maintain 

 was the necessity of drawing a distinction between primary and 

 secondary causes of the configuration of the country. He thought 

 that the operation of secondary causes had been overrated, and 

 wished that more attention should be paid to the circumstances of 

 the particular lakes to which he had called attention. 



April 30, 1873. 



Lieut. -Col. J. D. Shakespear, R.A. (retired), 22 Augusta Road, 

 Ramsgate; Richard Clifford Smith, Esq., of Parkfield, Swinton, 

 Manchester; and Rev. Edward S. Dewick, M.A., The College, East- 

 bourne, Sussex, were elected Eellows of the Society. 



The following communications were read : — 



