308 The American Geologist. May, 1892 
thickness. We are prepared to admit that the same thickness of 
glacierice may effect very different amounts of erosion in different 
regions; but we are not prepared to admit that a rough ridge of 
loose materials, standing squarely athwart the direction of ice 
movement, would constitute a belt where the erosion would be 
slight, if the ice passed over it in any considerable thickness. 
Dr. Wahnschatfe does not deny eroding power to the ice. Against 
such a view the great body of drift which covers north Germany 
stands as an unimpeachable witness. But his conclusion con 
cerning the origin of the topography of the Baltic ridge seems to 
us to necessarily imply that the ice sheet which buried the ridge, 
and advanced many miles beyond it, was here essentially impo- 
tent, so far as erosion is concerned. 
From what has preceded it will. be seen that the ‘‘ground mo- 
raine landscape,” arranged as it is in a great belt stretching across 
(yermany, corresponds with the terminal moraines of North Amer- 
ica. The constitution of the drift where this topography prevails, 
confirms this correlation. This relationship Dr. Wahnschatfe 
recognizes (p. 101), but it is to be distinctly borne in mind that 
the Baltic ridge, characterized by the topography which marks 
the terminal moraines of the United States, is not regarded asa 
terminal moraine by Dr. Wahnschatfe, or by most of the other 
north German geologists. The view of professor Penck that the 
‘‘moraine landscape” is the result of the intimate association of 
multiple terminal moraines (Hudmordéne), is more nearly in accord 
with the American view. But the formation to which the Ger- 
mans have commonly applied the name of terminal moraine 
(Ludmordne),is regarded by most of them as something very dis- 
tinct from the Baltic ridge. 
If the topography and the constitution of the Baltic ridge were 
not altogether conclusive in demonstrating its terminal morainic 
character, according to American classification, additional evi- 
dence might be found in the fact that it is bordered on the south 
by extensive plains of gravel and sand, corresponding to our over- 
wash plains (p. 107). The constitution of these plains corresponds 
exactly with that of plains in similar positions in our own country, 
heing coarsest near the moraine and becoming finer and finer with 
increasing distance from it. 
The intimate relationship between the ‘‘ ground moraine land- 
scape (equal the terminal moraine of the United States) and great 
