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THE JOURNAL OF GEOLOGY.

The Canadian Ice Age.Notes on the Pleistocene Geology of Canada, with Especial Reference to the Life of the Period and its Climatal Conditions.By Sir J. William Dawson, G.M.G., LL.D., F.R.S., F.G.S., etc.Montreal: William V. Dawson, 1893.301 pp., 8vo.

The work opens with a chapter of historical notices, embracing a sketch of the tenets held by the author during the long period of his studies on Pleistocene phenomena. Among these are the following: 1. The phenomena are not to be explained by any one cause, or by any one all-embracing hypothesis. 2. The astronomical changes that have been invoked are incapable of fully explaining the facts. 3. There has not been, at any time, a polar ice cap. 4. The phenomena indicate local mountain glaciers coöperating with floating ice in various forms. 5. The cold climate was mainly the result of peculiar geographical conditions and of a different distribution of oceanic currents. 6. The close of the period was not very remote. The author quotes freely from his previous writings in elucidation of these views, and cites certain recent tendencies that seem to him to indicate a drift of opinion towards the views he has held so long.

In the second chapter he gives the succession of Pleistocene deposits in Canada, as he correlates them, as follows:

Montreal and Lower St. Lawrence.	North Shore of Lake Ontario.	Belly River, Northwest Territory.
J. Wm. Dawson.	J. G. Hinde.	G. M. Dawson.
I.	I.	I.
Surface soil, post-glacial alluvia, and peat.	Surface soil, stratified sand and gravel.	Surface soil and prairie alluvium.
II.	II.	II.
Surface boulders, Saxicava sand and gravel. Boulders in and below sand.	Boulders, sand, etc. Laminated clay. Upper boulder deposit.	Upper boulder clay.
III.	III.	III.
Upper Leda clay, marine shells and drift plants. Lower Leda clay, marine shells and drift plants.	Stratified sand and clay, with fresh-water shells and plants.	Gray sand with iron-stone nodules. Brownish sandy clay. Carbonaceous layers and peat. Gray sand iron-stone.
IV.	IV.	IV.
Lower boulder clay or till. Many native and some traveled boulders. A few marine shells of arctic species.	Lower boulder clay or till. Native and traveled boulders.	Lower boulder clay. Many traveled boulders.