Vol. 60.] ANNIVERSARY ADDRESS. lxxxvii 



side, and even appear on the islands that flank the mainland of 

 Norway, some of them actually looking out to the open sea. The 

 supposed ice-sheet must therefore have lain mainly outside these 

 islands. But there is absolutely no evidence of any such detached 

 western ice-body, and every reason to believe that it never existed. 

 At the period of maximum glaciation the ice-sheet probably 

 advanced westward beyond the present limits of the land. But, 

 when it began to retreat, it would naturally creep backward up the 

 fjords, which would be still the main lines of ice-drainage. We 

 can conceive, indeed, that at an early stage of this retreat, a glacier 

 or ice-lobe may here and there have blocked up a large valley and 

 produced a lake, as in the instances cited by Prof. Suess from 

 Greenland. But the strand-lines of Western Norway are not 

 exceptional phenomena. They continue as characteristic features 

 of the coast-line and of the fjords for several hundred miles, and 

 must owe their origin to some general and widely-extending cause. 

 That they are true sea-beaches, as has been generally believed, I 

 have not the smallest doubt. 



Fortunately, we possess in our own islands a body of evidence 

 bearing on this question, not certainly as voluminous and im- 

 pressive as that of Scandinavia, but having the compensating 

 advantage of great simplicity and clearness. On the one hand, the 

 famous Parallel Boads of Glen Spean and Glen Boy, and those of 

 other less-known valleys, stand out as acknowledged relics of glacier- 

 lakes ; while round our coasts, on both sides of the country, raised 

 beaches, which have been hitherto regarded as old sea-margins, run 

 for hundreds of miles. These two series of terraces are found close 

 together, yet there is, I think, no difficulty in drawing a satisfactory 

 distinction between them. Indeed, their proximity enables us all 

 the more clearly to perceive their contrasts. 



There must, of course, be certain general resemblances between 

 the littoral formations of lakes and of the sea. 1 The erosion 

 produced by the waves or wavelets of a body of fresh Avater is 

 similar in kind to that performed by the sea, although different in 

 degree. In like manner, the beaches of deposit formed in lakes 

 possess, on a minor scale, many of the characters of those accumu- 

 lated along the sea-shore. And it may readily be granted that, in 

 isolated exposures of some old beach, it may be difficult or im- 

 possible to decide, in default of evidence from elsewhere, whether 



1 This subject has been instructively treated by Prof. Gr. K. Gilbert in his 

 monograph on Lake Bonneville, U.S. Geol. Surv. Monogr. no. i, 1890. 



