PREFACE. V 



As will be seen from the list of illustrations, 

 I have also to thank Mrs. John W. Elliot for 

 her valuable aid in that part of the work. 



On the other side of the water I have had 

 most faithful and efficient collaborators. Mr. 

 Auguste Agassiz, who survived his brother 

 Louis several years, and took the greatest in- 

 terest in preserving whatever concerned his 

 scientific career, confided to my hands many 

 papers and documents belonging to his broth- 

 er's earlier life. After the death of my 

 brother-in-law, his cousin Mr. Auguste Mayor, 

 of Neuchatel, continued the same affectionate 

 service. Without their aid I could not have 

 completed the narrative as it now stands. 



The friend last named also selected from 

 the glacier of the Aar, at the request of Alex- 

 ander Agassiz, the boulder which now marks 

 his father's grave. With unwearied patience 

 Mr. Mayor passed hours of toilsome search 

 among the blocks of the moraine near the 

 site of the old " Hotel des Neuchatelois," and 



