5i6 



POPULAR SCIENCE MONTHLY 



South America— the hypothetical line of demarcation between the Patagonian and Tropical 



American fauna marked . Centers of distribution in unbroken circles, and hypothetical 



lines of migration by arrows. 



comprehensive account of his collections had ever been prepared, created 

 the desire to examine this lavishly rich fauna. In the fall of 1887, 

 with Mrs. E. S. Eigenmann, I began work on Agassiz's unrivaled col- 

 lections, to which I had gained access through the courtesy of Mr. 

 Alexander Agassiz, the director of the Museum of Comparative Zoology, 

 and Mr. S. Garman, the curator of fishes. Financial and other reasons 



