THE GREAT ICE AGE 375 



minor areas of radiation may have temporarily existed on 

 smaller elevations : that this was followed by a period of more 

 equal level, in which parts of the low grounds were clothed 

 with a temperate flora, the " Interglacial period " so called, 

 succeeded by a second great depression, in which the high level 

 boulders of the second boulder drift were wafted to great dis- 

 tances by floating ice. 



The late Prof. Alexander Winchell, a man who did not 

 hesitate to express his convictions, thus bears similar testi- 

 mony : " There has been no continental glacier. There has 

 been no uniform southerly movement of glacier masses. 

 There has been no persistent declivity as a sine qua non, down 

 which glacier movements have taken place. The continuity of 

 the supposed continental glacier was interrupted in the regions 

 of the dry and treeless plains of the west ; and in the interior 

 and Pacific belts of the continent within the United States, 

 ancient glaciation was restricted to the elevated slopes. ' J1 He 

 might have added that the St. Lawrence valley was submerged 

 and received the ends of Appalachian and Adirondack glaciers 

 on the south-east, and those of Laurentide glaciers on the 

 north-west. 



My friend Prof. Claypole, who, however, has some hesitation, 

 fearing, I persume, to be cast out of the synagogue for heresy, 

 ventures to say, 2 " We deduce from the facts and arguments 

 stated above, that all the observations of glacial action in the 

 northern hemisphere are explicable by assuming the existence 

 of enormous and confluent 3 glacier-systems in and about the 

 high lands of Europe, Asia, and America, which high lands be- 

 came, therefore, glacial radiants, and shed their load of ice in all 

 directions over the lower adjacent ground, along the lines of 



1 Nov., 1890. 2 American Geologist, Feb., 1889. 



3 The term "confluent "is not necessary here. The glaciers of all 

 mountain chains may be said to be more or less confluent in the neve, 

 from which individual glaciers radiate. 



