Louis Agassiz (1807–1873), who had long been acquainted with his countryman, De Charpentier, spent several months with him in 1836, and together they studied the glaciers of the Alps. Agassiz was at first “adverse to the hypothesis, and did not believe in the great extension of glaciers and their transportation of boulders, but on the contrary, was a partisan of Lyell’s theory of transport by icebergs and ice-cakes ... but from being an adversary of the glacial theory, he returned to Neuchâtel an enthusiastic convert to the views of Venetz and De Charpentier.... With his power of quick perception, his unmatched memory, his perspicacity and acuteness, his way of classifying, judging and marshalling facts, Agassiz promptly learned the whole mass of irresistible arguments collected patiently during seven years by De Charpentier and Venetz, and with his insatiable appetite and that faculty of assimilation which he possessed in such a wonderful degree, he digested the whole doctrine of the glaciers in a few weeks.” In July, 1837, Agassiz presented as his presidential address before the Helvetic Society his memorable “Discours de Neuchâtel,” which was “the starting point of all that has been written on the Ice-age,”—a term coined at the time by his friend Schimper, a botanist. The first part of this address is reprinted in French in Marcou’s book on Agassiz. The address was received with astonishment, much incredulity, and indifference. Among the listeners was the great German geologist Von Buch, who “was horrified, and with his hands raised towards the sky, and his head bowed to the distant Bernese Alps, exclaimed: ‘O Sancte de Saussure, ora pro nobis!’” Even De Charpentier “was not gratified to see his glacial theory mixed with rather uncalled for biological problems, the connection of which with the glacial age was more than problematic.” Agassiz was then a Cuvierian catastrophist and creationist, and advanced the idea of a series of glacial ages to explain the destruction of the geologic succession of faunas! Curiously, this theory was at once accepted by the American paleontologist T. A. Conrad (=35=, 239, 1839). The classics in glacial geology are Agassiz’s Etudes sur les Glaciers, 1840, and De Charpentier’s Essai sur les Glaciers, 1841. Of the latter book, Marcou states that it has been said: “It is impossible to be truly a geologist without having read and studied it.” In the English language there is Tyndall’s Glaciers of the Alps, 1860. The progress of the ideas in regard to Pleistocene glaciation is presented in the following chapter by H. E. Gregory.