230 Tlte Ainri'!<-<ni Geologist. fxtobor, \m\ 
the (.'viilcncc tluit they luive been scooped out l)y the iee. Even 
this however, at least in the case of all which I saw, does not seem 
to me to necessitate the theory of the great erosive power of ice. 
All these basins which 1 saw lie in small valleys on the mountain 
tops whose presence seemed to depend on the fissure systems and 
on the varying depths to which loosening of l)locks had taken 
place. They lie at the foot of slopes down which the ice moved 
impinging with unusual force at its liase, where the greatest 
amount of polishing and striating has taken place. 
Those who hold the power of glaciers to vigorously erode hard 
rock under most circumstances it seems to me take an indefensi- 
ble position. At Muir glacier, in just the position where the 
greatest erosion would naturally be expected, soft gravels have 
been undisturbed by the ice. The key setting forth when glaciers 
will erode and when not, is certainly lacking at present. 
It is very advisable that a prolonged and detailed study of Muir 
glacier should be undertaken. It is a comparatively large glacier 
rapidly dying out, and presents an admiral)le opportunity for 
studying the behavior of a large glacier under such circumstances. 
Such work could not fail to prove of great value. 
PLEISTOCENE PAPERS AT THE WASHINGTON 
MEETINGS. 
The following brief notes of papers treating of the Pleistocene 
or Glacial period are arranged in the order of their presentation 
before the three successive scientific meetings in Washington, I). 
C, August 17th to September 1st, 181)1. 
American Associatioi* for the Advancement of Science. 
Section E. Geology and Geography. 
Source of supply to lateral and medial moraines. By John 
T. Campbell. A short paper, describing moraines in Indiana. 
Postglaeial anticlinal ridges near Ripley and Caledoniti, \eir 
Yorh. By G. K. Gilbert. In Ripley, the most western town- 
ship of New York bordering lake Erie, a cliff of Devonian shale 
forming the lake shore displays a small anticlinal disturbance of 
the Ijcds. which at the surface are raised in a ridge six or eight 
feet high. This disturbance extends down in gradually diminish- 
ing amount through the 40 feet to the lake level, but apparently 
not much lower. Jjike other small ridges of Devonian shale in 
