2G8

B. N. A. BOUNDARY COMMISSION.

especially by the existence of large areas which since the driftperiod have never developed systems of drainage valleys, and yet retainwith little modification the irregular appearance of the original surfaceof the drift deposit, and are dotted with numerous ponds and lakeswithout outfall. The pre-glacial streams too, choked up along the edgeof the third steppe hy the drift of the Cotoau, aud which have sincebeen unable to clear their channels, give evidence of this kind.