640 The Smithsonian Ins^ttion 



J. Geikie's "Glacial Geology" (1889) summarizes clearly 

 and comprehensively the recent progress in knowledge of 

 the events of the Quaternary in Europe. A. R. Wallace's 

 "The Ice Age and Its Work" (1893) affords an elegant 

 sketch of the rise of the glacier theory, and an able argument 

 in favor of the formation of lake basins by glacial erosion. 

 G. K. Gilbert's " History of the Niagara River " (1890) is an 

 elegant discussion of one of the most interesting problems of 

 American Quaternary geology. 



E. Desor's " Palafittes, or Lacustrian Constructions of the 

 Lake of Neuchatel" (1865) was given to the American pub- 

 lic through the medium of the Smithsonian Report, most 

 seasonably, when the evidences of the antiquity of man were 

 beginning to attract the attention of thoughtful men. 



II. EXPLORATIONS 



A PROMINENT department of activity in all the history of the 

 Institution has been the exploration of regions imperfectly 

 known, especially in North America. In some cases expedi- 

 tions have been fitted out under the direction of the Institu- 

 tion. In other cases aid and counsel have been given to 

 parties organized by private enterprise or by various depart- 

 ments of the government. These expeditions have resulted 

 in the acquisition of rich stores of knowledge of the geology 

 of the regions traversed ; and the National Museum has been 

 enriched with minerals, rocks, and fossils, as well as with 

 specimens illustrative of botany, zoology, and anthropology. 



One of the earliest of these expeditions was that of Thad- 

 deus Culbertson to the Mauvaises Terres of the Upper Mis- 

 souri in 1850; and the spoils of this expedition were a part 

 of the material with which Doctor Leidy began the study 

 of the Tertiary mammalian fauna of the West. In the Re- 



