704 PROF. GARWOOD ON THE ORIGIN OF SOME [Nov. 1902, 
In the first place, I feel that I owe to Prof. Davis an apology for 
entering as a critic into a field of research which he has made so pecu- 
hiarly his own. JI should like to urge, however, as an extenuating 
circumstance that, though I have written little, I have lived a large 
portion of my life among the glaciers of the Alps, and in particular 
in the neighbourhood of the St. Gotthard range. Had Prof. Davis 
selected any other district but the Val Ticino, I should most likely 
not have considered myself justified in criticizing his facts and con- 
clusions ; but with the Val Ticino I have had a long and intimate 
acquaintance, having traversed it on an average twicea year for 
upwards of twenty years, either on foot, in coach, or by train, and 
have a personal knowledge of nearly every gully and lake between 
Airolo and the Lago Maggiore. 
Under these circumstances, I feel bound to suggest an alternative 
origin, for the discordant lateral valleys which Prof. Davis has 
described, from that which he has advocated—a theory as to their 
origin which has been considerably strengthened by a study of the 
hanging valleys which I have met with in Sikhim and elsewhere. 
Il. Haneine VaLLEYs oF THE VaL TICINO. 
To the accuracy of the facts stated in Prof. Davis’s excellent 
description of the main features of the Val Ticino between Giornico 
and Biasca I can fully testify. The basal cliffs, the gentler slope 
forming benches above, and the open character of the valley below 
Biasca are familiar features; and I quite agree with him that 
‘the benches seem to be the remnants of the slower slopes of an ancient wide- 
open valley, in whose floor the present cliff-walled deeper valley has been 
eroded; and this supposition is confirmed when it is found that the high- 
standing lateral valleys are systematically related to the ancient rather than to 
the modern yalley-floor.’ (Op. cit. p. 146.) 
But when we come to the statement (op. cit. p. 147) that 
‘The famous corkscrew tunnels... . are therefore to be regarded, along with 
the stone posts of the grape- -arbours 1 in the vineyards about Biasca, as indirect 
‘consequences of glacial action,’ 
we have reached the gist of the matter, and I must join issue; 
for I cannot admit that this assumption of the over-deepening 
of the lower portion of the valley by direct ice-erosion is at all 
borne out by the facts of the case, even if we adopt Prof. Davis’s 
own line of argument, although, as I shall endeavour to show, 
ice has, in my opinion, been probably the indirect cause of the 
formation of the hanging valleys, but in a very different manner 
from that advocated by Prof. Davis. 
Let us review the evidence brought forward to support the theory 
that the lower portion ef the main valley below the benches and 
below the mouths of the hanging valleys has been entirely excavated 
by ice. This evidence rests on two facts: (1) the steep character 
