532 DR. J. W. SPENCEK ON THE ORIGIN OF THE 



have run up the valley by which the Grand River now came down 

 to the lake. All these lakes and the elevated regions between 

 them had been covered by glaciers, and their movement had been 

 in a contrary direction to that of the present water-drainage ; and 

 judging by the amount of drift-material transported by the ice from 

 the lake-basins over the adjoining land-surface, he believed that the 

 glaciers had been important factors in their excavation. If, on the 

 Author's views, there had been a recent submergence to the extent 

 of 1700 feet, where were there traces of marine remains over the 

 lake-region west of the meridian of Kingston, though such were 

 not uncommon in the clays of the St. Lawrence and Ottawa rivers ? 

 Also, on the Author's hypothesis of a former great lake whose 

 surface would be at a considerable elevation above the sea, what 

 barrier was there at the south end of Lake Michigan, near Chicago, 

 to keep such a lake from draining into the Mississippi valley ? 



Prof. BoNNEY thought that Dr. Hinde's criticism was not a valid one, 

 as he had not understood that the Author denied the occupation of the 

 lakes by ice, though he did not uphold their glacial origin. He could 

 not understand the formation of Georgian Bay by ice and the pre- 

 servation of Manatoulin Island. He was struck with the similarity 

 of tbe Author's sections and those of the Lake of Como, published by 

 the late Mr. J. Ball, which he had previously shown to be adverse to 

 the glacial theory of the origin of lake-basins. It was not safe to 

 argue from the absence of remains of marine organisms ; for else- 

 where they were commonly wanting in deposits formed under cir- 

 cumstances similar to these, yet undoubtedly marine. He, again, 

 could not follow Dr. Hinde in his objections to differential movements 

 of the earth's surface, and insisted on the great movements of recent 

 times, as evidenced along the Frazer River and in jN"orway. Only 

 last autumn he had seen distinct evidence of comparatively modern 

 depression along the Dalmatian coast. He suspected some changes 

 even in historic times. The buried river-channels described by the 

 Author were paralleled in Switzerland. He did not deny the 

 efficiency of ice to produce some effect, but it did not bring about 

 what had been attributed to it by some geologists. 



Dr. Irving congratulated the Author on the results he had placed 

 before the Society. He thought Dr. Hinde had not followed 

 Dr. Spencer's arguments throughout, as, for instance, in the case of 

 the connexion between Huron and Ontario. He was glad to find the 

 main points of his own theoretical conclusions as to the inability of 

 ice to excavate confirmed by the Author's observations in Norway and 

 America. He saw nothing startling in the " warping" hyiDothesis. 



Mr. Clement Reid had no objection to Dr. Spencer's views on 

 " warping." He thought all turned on accuracy of observation 

 in tracing the terraces, and he wished to know whether it was 

 absolutely certain that the same terrace was traceable throughout 

 the whole distance. 



Rev. E. Hjll called attention to the fact that tracts of Lake 

 Superior were now below sea-level, and yet no marine deposits 

 are forming there. He called attention to the advantage of the 



