150 The Author of the Glacial Theory. 



statement. That theory has done yeoman's service in recent 

 works on the geographical distribution of animals and plants, 

 and, if it be a fantastic dream, it seems curious that we may 

 search the works of the great prophets of the glacial theory 

 in vain for any definite repudiation of it. One would sup- 

 pose, for instance, that in the two monographs by Mr. Geikie 

 above-named, both of them published after Agassiz's famous 

 journey to Brazil, there would be found something to warn 

 students who may have need of the glacial theory for their 

 own work, that Agassiz's views about the glaciation of the 

 valley of the Amazon are preposterous. Nor can I find a sen- 

 tence in which Agassiz's views are impugned by name at all. 

 If, then, there has been a general rejection of his later 

 views by those professedly his scholars, where is it to be 

 found ? They assuredly owe it to his memory and to the 

 world of science, to make it quite clear how far they go with 

 him, and whether they have anything but a priori grounds 

 for repudiating the positive statements made by Agassiz, by 

 Hartt, and by Belt, who all visited the tropical regions of 

 America, and who were all trained geologists, that the facts 

 they saw in the valley of the Amazon and in Nicaragua, and 

 which included roches moutonnees, erratics, and other drift 

 phenomena, were not the debris of ordinary subaerial 

 denudation, as Professor James Geikie urged at Newcastle,, 

 but precisely similar to the drift phenomena of North America 

 and Europe, and merely proved the extension of the ice 

 sheets from the 46th parallel to the equator. For people 

 who hold my views, Agassiz's later theories, like his earlier 

 ones, are as valuable as most transcendental works in science ; 

 but for believers in ice sheets, themselves the scholars of 

 Agassiz, it is a very different matter. 



