SUPPOSED GLACIAT10N OF BRAZIL. 7S7 



Thomas Belt, the author of The Naturalist in Nicaragua, says 

 in that volume 1 that though no ice marks are visible he has seen 

 "near Pernambuco, and in the Province of Maranham, in Brazil, 

 a great drift deposit that I believe to be of glacial origin." 



I have seen and studied the deposits to which Belt refers ; 

 my opinion is that while they bear a certain resemblance to 

 glacial drift they are entirely devoid of positive evidence of 

 glacial origin. The method of their formation is explained in 

 another part of this paper. 2 



AGASSIZ'S CHANGE OF VIEWS. 



It is appropriate that I here quote from Professor N. S. Sha- 

 ler, a former pupil of Professor Agassiz: 3 



" There has been a good deal of discussion concerning the former exist- 

 ence of glaciers in the valley of the Amazon. Agassiz, to whom we owe the 

 first suggestion of the value of glaciation as a great geological agent, at one 

 time thought it likely that the valley of this great river had been the seat 

 of a glacier that poured its ice from the Andes nearly down to the sea. This, 

 which was hardly more than a suggestion put forth for the discussion of geological 

 students, was, I believe, practically abandoned by this illustrious naturalist 

 before his death, (In this assertion I have embodied the results of several 

 remarks by my late master on this subject made during the last two years of 

 his life. It is satisfactory to know that the only considerable mistake he made 

 in the matter of glaciation was corrected by his own reflections on the subject. 

 N. S. S.) and has been found to be an essentially mistaken view. The late 

 Professor Hartt, geologist of Brazil, at one time thought some of the debris in the 

 mountain districts near Rio de Janeiro was of glacial origin, but this sugges- 

 tion has never been submitted to discussion, and can have no weight against 

 the other evidence of a negative kind that goes to show that glaciation, save in 

 higher mountain countries, has never extended into the intertropical regions." 



1 The Naturalist in Nicaragua, by Thomas Belt, F.G.S., 2d ed. London, 1888, 265. 



2 It has been asked how I reconcile Belt's statements regarding glaciation in Nica- 

 ragua with my inability to find trustworthy evidence of glaciation at a similar south 

 latitude. I don't try to reconcile them ; I am simply dealing with the facts as I know 

 them in Brazil. I have never seen the Nicaraguan deposits, but I can't avoid suspect- 

 ing that they will turn out like the Brazilian ones, J. Crawford's moraines and 

 "moutonned ridges" to the contrary notwithstanding. (Proc. Amer. Assoc. Adv. Sci., 

 XL., 265, and Science, XXII., No. 263, p. 270). 



3 Glaciers, by N. S. Shaler and W. M. Davis, Boston, 1881, 47. 



