60 Scientific Intelligence. 
merged. On looking more closely I observed that the sodden 
snags of dead timber, mingled with stones, were often to be seen 
at the bottom of the inshore waters, and that the beds of fresh- 
water lakes were plentifully strewn with similar fragments of wood, 
the remains of forests prematurely destroyed. As the soilcap, by 
its sliding motion, reaches the water, the soluble portions are re- 
moved ; and just as stones and bowlders are often seen deposited 
ror ta ioe the class of cases to which I refer, due to a totally 
differ use. These facts are all the more interesting from 
their pits in a region where the effects of o/d glacial action 
are to be seen in a marked degree. Planings, scorings, striz an 
“roches moutonnées” may almost invariably ‘be found wherever 
the rock is sufficiently capable ° resisting — disintegrating 
influence of the weather to retain these impressions. us they 
are nowhere to be seen on the ¢ eosin friable syenite, 
which is the common rock-formation of the district; but where 
this rock is intersected by dikes of the more durable greenstone, 
the above-mentioned signs of former glacial action may n 
well developed. There are therefore in this region ample oppor- 
tunities of comparing and differentiating phenomena which have 
resulted from “ glacial action” and those which are due to “ soil- 
cap-motion”—a force now in active operation 
may here observe that we did not see any glaciers worthy of 
the name either on the western islands or abutting on the mainland 
shores of Patagonian channels, although oe oa exist so 
ther eastward, and discharge icebergs at the head of some o 
deep fiords. In the main straits of Magellan thet are fine samples 
of complete and incomplete glaciers, where may be observed, in all 
its grandeur, the wonderful denuding power hich these ponder ous 
masses of ice exercise as they move silently along their rocky beds. 
Sir Wyville boars (vide ‘ Voyage of the Challenger,’ the 
“ Atlantic,” vol. ii, p. 245) attributes the celebrated “stone rivers’ 
of the Falkland ined to the ——— action of the soileap, 
i mong other causes, der its motion from expansion an 
extent supported at the occurrences which I a m now endeavoring 
to describe. Here, in Western Patagonia, are evergreen forests, 
nd a dense undergrowth of brushwood and mosses clothes the 
hillsides to a height of about 1000 feet; and this mass of vegeta- 
tion, with its subjacent soil, resting as ‘it frequently does upon a 
hillside already planed by Penney naturally tends, under the 
influence of gravitation, combined with that of expansion and con- 
traction, to slide gradually javword until it meets the sea or a 
lake or valley. In the first two cases its free edge is then removed 
by the action of the water, in a manner somewhat analogous to the 
wasting of the submerged snout of a Greenland siattees in the sum- 
mer time; and in the ‘last case the valley becomes converted into 
a deep morass. 
