754 THE JOURNAL OF GEOLOGY. 



lectures in which he suggested to his assistants the possibility 

 of the South American continent having been glaciated, and 

 reminded them that this was one of the important subjects for 

 their investigation. 1 



I subsequently learned from Professor Hartt, who was one 

 of the assistants, that these lectures prepared them to be con- 

 vinced that glaciation had taken place in Brazil, though he him- 

 self was rather inclined to believe otherwise. 



Mrs. Agassiz's book shows throughout how Professor Agassiz 

 found on every hand, from the time he landed in Brazil till he 

 left there, what he regarded as evidences of glacial action. 

 In the mountains about Rio de Janeiro he found erratic boulders 

 (pp. 86 et seq.y, at Erere, in the Amazon valley, he found "the 

 only genuine erratic boulders I have seen in the whole length 

 of the Amazon valley," (p. 418); he declared that "il n'y a pas 

 trace des terrains tertiaires" 2 in that region, while the horizontal 

 sediments of that valley he explained as silts thrown down in 

 cold glacial waters behind a vast terminal moraine that stretched 

 across the mouth of the valley (p. 426), and of which the 

 island of Marajo was supposed to be a remnant ; the table-topped 

 hills he explained as the remnants of sediments left when this 

 great dam broke, and the waters swept the greater part of the 

 beds out to sea. 



The lateral moraine on the south side of this great glacier 

 he expected to find in the interior of Ceara (p. 447-8); he went 

 to Ceara, and found at Pacatuba, near the coast, what he regarded 

 as glacial phenomena " as legible as any of the valleys of Maine, 



1 A Journey to Brazil, by Professor and Mrs. Louis Agassiz, Boston, 1868, 

 15. In Mrs. Agassiz's Life and Correspondence of Louis Agassiz, Boston, 1886, II. , 

 633, it is further stated that Agassiz was confirmed " in his preconceived belief that 

 the glacial period could not have been less than cosmic in its influence." 



2 Bui. de la Soc. Ge'ologique de France, XXIV., no. In a letter to Elie de Beau- 

 mont, he speaks of these beds as loess, but he gives no specific explanation of their 

 formation. Comptes Rendus de l'Acad. des Sciences, 1867, 1269. Professor Agassiz 

 first published his paper on the Physical History of the Amazon valley in the Atlantic 

 Monthly for July and August, 1866; it was also published subsequently in his 

 Geological Sketches, sec. ser. Boston, 1886. IL, 153 et seq., and in the Journey to 

 Brazil. 



