ARNOLD HENRY GUYOT. 495 



To quote his own statement as to what he had then learned : * 

 " The glacier of the Aar, on which Agassiz began two years 

 later (1840) his regular system of observations, taught me the 

 law of the moraines. The glacier of the Rhone gave me the 

 law of the more rapid advance of the center of the glacier and 

 that of the formation of the crevasses, both transversal and 

 longitudinal. The glacier of Gries showed me the laminated 

 or ribboned (blue bands) structure of the ice deep down in the 

 mass of the glacier, and the law of the more rapid advance of 

 the top over the bottom. On the southern slope of Mont 

 Blanc, the great glacier of La Brenva, with its twin rocks, rising 

 like two dark eyes from the middle of the ice (they are indeed 

 called by the mountaineers the ' eyes of the glacier '), made 

 me understand that the motion of the glacier takes place by a 

 gradual displacement of its molecules under the influence of 

 gravity, giving it a sort of plasticity, and not by simultaneous 

 gliding of its whole mass, as believed by De Saussure. All 

 these laws, deducted from a first but attentive study of the 

 phenomena of the glaciers, were at that time, excepting that 

 of the moraines, new for science." 



Agassiz was intensely interested by Guyot's discoveries, 

 and appears to have gone the next year and discovered the 

 same things. Then, with his customary enthusiasm and genius 

 for organizing great enterprises, he proposed a joint research in 

 which Guyot was to have the distribution of erratic rocks in 

 Switzerland as his exclusive province, resigning to Agassiz all 

 that concerned the structure and movement of glaciers, in 

 which the former had made such a brilliant beginning. As 

 part of this plan, in which Guyot modestly accepted the place 

 assigned him, the Porrentuy paper was to remain unpub- 

 lished. Two years later arose the fierce controversy between 

 Agassiz and Forbes as to priority in certain glacial discoveries. 

 Faithful to the spirit of the above agreement, Guyot took no 

 part in this wordy war, allowing Agassiz to use the work of 

 both as his own. The latter repulsed Forbes's claim as to the 

 blue bands, and secured the credit for Guyot by publishing 

 that part of Guyot's paper describing them, and, in order to 

 have the rest of the paper as ammunition for future use, de- 

 posited the manuscript in the archives of the Society of Natural 



* Memoir of Louis Agassiz. 



