JEAN LOUIS RODOLPHE AGASSIZ. 483 



the survey of Massachusetts Bay. From this time to the end 

 of his life, under Superintendents Bache and Pierce, courtesies 

 were frequently extended to him by the Survey, to the specific 

 benefit of the latter's work as well as of science in general. 



Agassiz had not been two years in this country before he 

 began publishing in English. The first part of Principles of 

 Zoology, by L. Agassiz and A. A. Gould, appeared in 1848. 

 Several editions were disposed of, mainly for school use, but 

 its sale was checked by the lack of a concluding part, which 

 was never issued. The same year, in connection with H. E. 

 Strickland, he began the publication of a Bibliographia Zoolo- 

 gies, et Geologic. This work, which comprises a list of all the 

 periodicals devoted to zoology and geology, and an alphabet- 

 ical list of authors and their works in the same departments, 

 was completed in four volumes, the fourth being published 

 in 1854. 



Agassiz's studies on the glaciers of Switzerland led him to 

 expect to find in the United States many traces of former ice 

 action. Nor was he disappointed. He explored the country 

 from the Atlantic to the Rocky Mountains, from the Great Lakes 

 to the Gulf of Mexico, and everywhere, north of the thirty-fifth 

 parallel of latitude, found evidences of glacial action, in erratic 

 blocks, polished and striated rock surfaces, and terminal mo- 

 raines. Naturally this served to confirm his belief in the uni- 

 versality of the ice period ; and, upon his departure for Brazil, 

 in 1865, he announced his confident expectation of finding 

 records of the former existence of glaciers in that country; 

 for he believed that not only most of the Northern, but also 

 most of the Southern Hemisphere was, during the glacial 

 epoch, encased in ice. The evidences of glacial action in the 

 United States are fully discussed by Agassiz in his Lake Su- 

 perior, a work on the physical character, vegetation, and ani- 

 mals, of Lake Superior, compared with those of other and simi- 

 lar regions. 



Agassiz was a firm believer in the diversity of origin of the 

 human race, and his views on this point are ably presented in 

 the Christian Examiner for July, 1850, and in an introduction 

 to Nott and Gliddon's Types of Mankind. The geographical 

 distribution of animals shows, he maintained, that distinct zoo- 

 logical provinces are each characterized by peculiar fauna, and 

 that therefore animals did not originate from a common centre 



