L20 The A iin ricn ii Geologist. February, 1894 
the temparature in the Ice age in Canada, rather than a very severe 
climate. This was in his estimation the dominant cause of the Glacial 
period, and in support of his views he brings forward evidence from the 
Hora and fauna of the period, which, he says, bears strongly in that 
direction. He writes: 
"One can to-day dredge in a living state off Metis in the river St. 
Lawrence all the species found in the upper Leda clay of the neighbor- 
ing coast. In like manner the vegetable remains of the upper Leda 
clay and its equivalent in the west are not arctic but boreal plants, and 
we should have to go near to the arctic circle, then as now, to find the 
true arctic flora. These facts show that the climate of the mid- 
Pleistocene was not an arctic one." (Page 136.) 
Passing on next to consider the date of the Glacial period, our author 
asserts plainly that the results of geological study in North America 
will by no means allow the distant date assigned by CrolFs astronomical 
theory, but that on the other hand this evidence, though somewhat va- 
rying in detail, points with a surprising unanimity to an epoch between 
eight and fourteen thousand years before our own day as the time of 
the close of the Ice age. This is of course a very strong confirmation of 
the view that the dominant cause of glacial conditions was telluric and 
not cosmical. 
To conclude, we will give the author's summary of the conditions of 
the Pleistocene period in Canada (page 36). 
Newer Pliocene.— A continental period of long duration, in which the land was 
higher than at present, and very extensive erosion of deep river valleys oc- 
curred. 
Pleistocene. -Covering three subdivisions: — 
hi Early Pleistocene, with irregular elevation and depression of the continents, 
cold climate and great local glaciers, 
i b) Mid-Pleistocene, with submergence of coasts, re-elevation of interior plateaus. 
and milder climate.— Interglacial period, 
(c) Later Pleistocene, with submergence of plains, general ice drift, and local 
glaciers in the mountains. 
Early. Modern or Postolacial.— Second continental period, in which the land re- 
gained almost all the extension of the Pliocene time. Age of the mammoth, 
mastodon, and of Palreocosmic man. — Postglacial fauna. 
Modern or Recent.— Submergence of short duration, terminating bhe age of Palaso- 
cosmic man. Re-elevation of continents to present levels.— Modern fauna. 
We cannot follow our author into the local details and the especially 
useful tables of fossils with which he concludes. However widely we 
may differ from him on some points, we recognize the timeliness ami 
value of the work. To run to extremes seems inevitable, and the gla- 
cial controversy has been no exception to the rule. When the ice- 
specter reached his full stature, and in the vision of the great master 
even the valley of the Amazon was ice-enveloped and clogged with mo- 
rainic matter, when, to the view of some of his followers, the 
two poles of the earth were alternately so laden and overborne with 
their ice-caps that the globe was thought to be in danger of losing its 
balance, the "glacial nightmare*' may be considered to have reached its 
severest incumbency. Since then the pressure has somewhat relaxed. 
In like 'manner, our author is, we think, disposed to put upon the theory 
