352 
the Tonawanda and other large tributaries coming in at right angles to the 
consequent streams are the subsequent streams and some of their valleys 
are now the basins of the Great Lakes. 
Short gullies, or tributaries to the subsequent streams, called obsequent 
streams, worked headward into the cliffs of the cuestas. Such a stream 
was the St. David’s gorge, which, however, was not the preglacial Niagara, 
as was once believed by Scovell, Pohlnan (S84) and others. 
The direction of preglacial drainage postulated by the theory above 1s 
in accord with the theories of Upham (128), Westgate (187), Russel (88), 
and also A. W. G. Wilson, who has worked the preglacial drainage of the 
region east and north of Lake Ontario in detail (140) (Plate VI). 
