700 PROF. T. G. BONNEY ON [ Nov. 1902, 
removed by merely stating that they may be masses left by the 
ice, as islands are by running water. He ought at least to show 
some reason—such as the occurrence of unusually hard material, 
for their escape from the oppressor. Now certain of these I know, 
especially that at Sion, and venture to say that he will find this 
difficult. 
Again, a wonderful faith in ‘strong glacial erosion’ is required 
before we can believe the upper part of the Gasterenthal to have 
been excavated by a glacier. J have ventured to maintain that 
the far humbler Kirchet presents serious difficulties’; and how any 
such hypothesis is to fit the widening of the valley above the Klus 
on the Landquart, or the step down to Klosters from the valley in 
which Davos lies—a region even now with few and small glaciers— 
to mention no other cases, passes my comprehension. 
(5) Beheaded valleys, the executioners of which, as has been 
proved at the Maloja Pass, have been the ordinary meteoric agents 
(working in this case from the Italian side of the Alps, where 
fluviatile erosion would be more active than on the northern side), 
are more common on the main range, because there these agents 
have been longest at work.’ 
(6) When not thus beheaded, a valley commonly expands in its 
uppermost part (though occasionally it keeps the furrow-form to but 
a little below a pass). This expansion is somewhat on the corrie- 
type, a ‘ wall,’ or at any rate a steep rise, forming the last portion 
of the ascent. As therills gather into streams, and these into rivers, 
the valley becomes more V-like, the slope of the sides steepening 
as the torrent increases in erosive strength: so the Y-type (where 
the rocks are unchanged) probably indicates a rather rapid increase 
in the power of the torrent.” 
(7) In all parts of the Alps we can trace, beneath the undulating 
contours impressed by the glaciers, the ordinary features due to 
other meteoric agencies. The broader outlines of the valleys, 
whether those at higher elevations, which are still occupied by névé 
and glacier, or those at lower, which are either bare or merely 
patched by one or two snow-beds,—valleys, in short, which snow 
and ice have occupied since Pliocene times, as well as those which 
they only invaded in the Ice-Age,—are in all cases practically 
identical, provided the rock is similar. 
I have been obliged to speak rather dogmatically, because if 
every statement were fully proved, the details would be so numerous. 
1 Alpine Journ. vol. xix (1899) p. 29. 
2 See Alpine Journ. vol. xiv (1889) pp. 224-52, for details. The crest of 
the Pennines at the head of both branches of the Vispthal affords, as there 
explained, wonderful instances of this process. I have little or no doubt that. 
the snowfields on the Monte-Moro Pass, and others in that neighbourhood, 
were once much more extensive and rose to a greater elevation. 
3 I may refer for details to the chapters on mountains and valleys (pp. 55— 
157) in the ‘Scientific Study of Scenery’ London, 1900, by my friend 
Mr. J. E. Marr, from which I should differ at most on one or two points of 
detail. 
