British geologists must have read Professor Coleman's Address to the Geological Section of the British Association with great pleasure and interest. As Professor Coleman remarks, geology finds some of its most seductive problems in the neglected extremes of the earth's history. Out of the apparent tangle of the ‘drifts’ and Archæan Gneisses Canadian geologists are now evolving an orderly sequence which must exercise considerable influence upon the progress of geology in other lands. The seemingly unnatural conjunction of Pleistocene and Archæan, Professor Coleman states, has furnished the clue to certain puzzling problems of the Archæan.