LAMPLUGll: GLACIATIOX IX VANCOUVEK ISLAND. 
65 
country, and possibly that it never extended much beyond this 
point." But with this I do not altog-ether agree ; as I think there is 
evidence that the ice extended much lower in Puget Sound ; nor do 
I think that a mass of ice which was certainly more than 700 feet 
thick could have accumulated rapidl}' in a region like this. It is 
more likely to have gathered slowl}^ as in a basin from the mountains 
all round. 
One has heard so much of the enormous erosive power of ice, 
that I, for one, had come to think of a strong-ly- glaciated district as 
one from which a great thickness of rock must necessarily have been 
removed. And 1 do not suppose I was singular in the supposition, 
for the writings of our leading gkcialists all tend to strengthen 
this view. But I now find myself regarding the presence of much 
roche moutonnee in such a district as primcL facie evidence that the 
glaciation has probably been superficial ; for I am inclined to think 
that a huge mass of ice in motion would not be likely either to 
initiate or accentuate minor inequalities of surface, but would on 
the other hand, have a constant tendency to level or remove them. 
It is true that in the rocks under consideration there are man}^ 
small seams and veins of harder material which stand out a little 
way on a glaciated rock-surface, but whatever their i-elative hardness 
may be, the limit of their protuberance is soon reached and the 
projecting portion ground off, so that the general outline is scarcely 
affected. And though, no doubt, it is to the mineral character of the 
rocks that the main features of the surface are due, the erosion s;^ems 
to have taken place before, and not during, the passage of the ice. 
It is for glacialists to decide how such a body of ice, whose 
very mass, as I understand it, presupposes in an area like this a slow 
process of accumulation, can have covered for a long time a region 
of this kind with such a partial and erratic expenditure of force. 
I would also draw their attention to the cliff-section which I saw 
near the foot of the Muir Glacier in Alaska, described in the third 
part of this paper, in which a great mass of ice directly overlaid 
bedded sands and gravels without disturbing them. 
In conclusion, I must acknowledge that I have made very poor 
use of extremely interesting material, and if it were only in my 
