April 2 A,, 1879] 



NATURE 



575 



result of a depression of temperature toward the end of 

 the tertiary covered North and Central Europe, Asia, and 

 North America, and a similar phenomenon was also 

 found to have occurred in South America, from the South 

 Pole to Monte Video and Chile, as Agassiz ascertained 

 during the Hassler Expedition of 1872. The immense 

 importance of this theory, both in geology and biolog>-, 

 was soon recognised, and its discussion has engaged the 

 earnest attention of the ablest men in all departments of 

 science. In the autumn of 1846 Agassiz went to America, 

 partly on a commission from the Prussian Government 

 and partly to fulfil an engagement to give a series of lec- 

 tures on Comparative Embryology at the Sewell Insti- 

 tute of Boston. This course of lectures led to important 

 results ; it aroused an enthusiasm for the study of nature 

 in the widest circles, and Agassiz understood how to make 

 the scientific development of North America in this direc- 

 tion a matter of honour for the whole nation. The offer 

 of the use of the steamers of the Coast Survey led to a 

 scientific cruise in the summer of 1847 along the coast of 

 Massachusetts, followed a i&yfi years later by a second 

 larger cruise to the coral reefs of Florida. 



After Agassiz had been released from his scientific 

 mission by the Prussian Government, he accepted with 

 pleasure the Chair of Zoology and Geology in the 

 Lawrence Scientific School of Harvard College, Cam- 

 bridge, created specially for Agassiz by the founder of the 

 school, Mr. Abbot Lawrence. Agassiz thus gave up all 

 thought of returning to Europe ; he placed his activity, 

 his science, and his talents, at the disposal of the nation 

 that showed itself so anxious to keep him, and where he 

 would enjoy a social power and a liberty which were 

 hardly possible to the savaiis of the Old World. 



As in Neuchatel, so in Cambridge, Agassiz in a very 

 short time attracted around him a circle of yoimg men, 

 enterprising lovers of natural science. With these, in 

 June, 1848, heundertookajoumey to the then little-known 

 region of Lake Superior. In 1850 appeared his well- 

 known work, " Lake Superior : its Physical Character, 

 Vegetation, and Animals," in which Agassiz discussed in 

 detail the erratic phenomena of the lake, its future form 

 and extent, the character of its ichthyological and rep- 

 tilian fauna, while Cabot, Harris, Gould, and J. Leconte 

 worked out the rest of the collections. In succeeding 

 years he made similar expeditions with his pupils into 

 the interior of the United States, and with the collections 

 brought back laid the foundation of a natural history 

 museum, which, until then, had no existence at Harvard 

 University. 



In 1852 Agassiz went to Charleston as Professor of 

 Zoology and Comparative Anatomy, but returned to Cam- 

 bridge after two years, the warmer climate of the south 

 not agreeing with him. Soon after he visited all the 

 great towns of North America, lecturing in all depart- 

 ments of zoology and geology. Everywhere he was re- 

 ceived with enthusiasm, for his expositions were remark- 

 ably clear and full of suggestive thought, his language 

 noble and fluent, his knowledge of human science of the 

 widest, his manner so charming and his conversation so 

 full of the highest instruction, that every one felt it a 

 privilege to be near him. From that time Agassiz be- 

 came the declared pet of the Americans ; he was the 

 most popular man in the whole broad land, and in intel- 



lectual matters became its greatest benefactor, exercising 

 his influence in improving education and increasing edu- 

 cational establishments. 



In 1855 Agassiz began to prepare for the publication 

 of a magnificent work, " Contributions to [the Natural 

 History of the United States," he having already pub- 

 lished several papers on the subject in American journals. 

 In a short time the necessary means were obtained by 

 subscription, and in 1857 the first volume appeared, dedi- 

 cated to Dollinger and his generous friend Francis Calley 

 Gray. Unfortunately this work only reached the fourth 

 volume. The first volume contained as introduction 

 the universally- known and much-discussed " Essay on 

 Classification," which latter, as a separate work, was 

 published in London in 1859, and in an enlarged French 

 translation in Paris, 1869. Agassiz treated in this work 

 the questions of the origin, development, and systematic 

 arrangement of the organic world, and developed from 

 these his philosophical views which he had obtained from 

 his own studies and observations, and which stand in 

 direct opposition to the Theory of Descent. 



Agassiz's collections had grown so enormously that the 

 accommodation at his disposal was quite inadequate. By 

 the liberality of Mr. F. C. Gray and the State of 

 Massachusetts, as well as Cambridge^University, a great 

 Natural History Museum was begun in June 1859, and 

 by December was so far advanced, that the greater part 

 of Agassiz' s collections could be transferred to it. From 

 this time the improvement and completion of this 

 museum became the chief object of Agassiz' s activity. He 

 aimed at making it in comprehensiveness and suitability 

 for its piu"pose, a pattern institution for the whole world, 

 and fitted to give the friends of natural history all 

 possible help in their researches. The Museum of 

 Zoology and Comparative Anatomy is much better known 

 to the public of Cambridge and Boston as "Agassiz's 

 Museum." 



In 1864-65, Agassiz somewhat broke down from his 

 continued labours, and he was advised to travel. He 

 decided to visit Brazil, the fish of which furnished him 

 with the subject of his first work. With six assistants 

 he left New York in April, 1865, for Rio Janeiro, The 

 party divided to work in various directions, Agassiz, him- 

 self, selecting the Amazon as his sphere, sailed up the 

 river to Manaos, at the Mouth of the Rio Negro, and 

 thence to Tabatinga. During the journey from Para to 

 Manaos 300 species of fish were collected, of which one 

 half were drawn from life by Burkhardt. His head- 

 quarters were at Teffe and Manaos, where he studied tke 

 habits of the fish in their migrations in the main stream, 

 and several of its tributaries. While he stayed here, his 

 assistants explored some of the other tributaries of the 

 Amazon, while others explored the regions on the Rio 

 Francisco, Rio Doce, Paranahyba, &c. In July of the 

 following year Agassiz returned to the United States with 

 such a collection of booty as would have fiUed another 

 Museum. With the co-operation of Agassiz, his wife, the 

 true companion of her husband, and full of sympathy for 

 his ideas, brought out the journal of these remarkable 

 travels, which in a short time reached a sixth edition in 

 America, and was translated into French in 1869. 



Again, in the end of 187 1, Agassiz left for South 

 America, on board the war-ship Hassler, Count Pour- 



