LAKE TITICACA 149 



The Lake never freezes, although plenty of ice is formed 

 along the shores, which invariably disappears before the 

 sun gets high. It is then hot in the day, while the sun 

 shines, but quite cold at night as soon as the sun has 

 set, cold enough to freeze hard. I expect to leave for 

 home by the steamer of March 14 for Callao and to 

 reach New York about the tenth of April. 



The foregoing letter explains only in part why Agassiz 

 brought back from Lake Titicaca more alcohol than 

 specimens. For the exploration of this elevated sheet 

 of water disclosed a condition of things similar to the 

 marine life of the Arctic regions — a great abundance 

 of specimens, with a comparatively small number of 

 species. As in the case of many other isolated sheets of 

 water, its few species were peculiar to the lake. The 

 collections brought out the curious fact that, whereas 

 the Mollusca were species of fresh-water genera, the 

 Crustacea, on the other hand, belonged, with the excep- 

 tion of one species, to the Orchestiidae, forms which 

 hitherto had not been reported from strictly fresh 

 water. But his work in another field, to which he now 

 first turned his attention, yielded a rich harvest of 

 Peruvian mummies, Inca relics, and implements of 

 the modern Indians. These he gave to the Peabody 

 Museum. 1 



Twenty years later, when visiting the zoological sta- 

 tions of Europe, and looking up his scientific friends, 

 he was amused to find at the Ethnographical Museum, 

 in Berlin, collections that had been offered him at Lake 

 Titicaca at a fabulous price, and had been purchased lately 

 for a song, owing to the death of the owners. He dis- 



1 The south wing of the University Museum. 



