SHODIES HOR SROUDENTS. 89 
tion, structure, form and relationship, these valley plains resemble 
the many valley deposits of stratified drift, which stretch beyond 
the unstratified drift in our own country and northern Europe. 
All these considerations make it clear that there are many 
points in common between the deposits made by alpine glaciers, 
and the drift of the continental areas. Indeed, the correspond- 
ences between the two formations are so close, so numerous, and 
comprehend so many phenomena related to one another in inti- 
mate and nicely adjusted ways, that it is difficult to see how they 
could have been brought into existence by any other than identi- 
cal agencies. 
The physical heterogeneity of glacier deposits considered in 
relation to the sources whence their materials were derived; the 
lithological heterogeneity of these deposits likewise considered 
in relation to the sources whence the materials came; the sizes, 
shapes, and marking of the coarser parts of these deposits; the 
physical and chemical condition of their finer parts ; the stratified, 
unstratified, and foliated structures of the various parts of these 
deposits in their relations to one another and to topography ; 
the relation of these deposits to the rock upon which they rest ; 
the frequent termination of the unstratified parts on declining 
surfaces ; the extension of the stratified parts far down the valleys 
beyond the unstratified parts; the topographic relations of these 
deposits and their own topography ; the systematically disposed 
strie on the rock beneath them, taken in connection with the 
direction in which materials have been transported ; the shapes of 
the hills worn by glaciers, and the relation of these forms to other 
associated phenomena; the general surface expression of the 
region worked over by a glacier, in contrast with adjacent regions 
which have been so affected; all these phenomena, so peculiar, 
so distinctive, and particularly all these phenomena in their 
manifold, and intricate, and peculiar, and nicely adjusted rela- 
tions, afford a remarkable series of criteria for the recognition 
of glacier deposits, even in regions which now possess no 
remnant of ice. 
The various marks left by glacier ice on the bed over which 
