542 LOUIS AGASSI Z, 



by adding your name to the list of my sub- 

 scribers. . . . 



Believe me always truly yours, 



RICHARD OWEN. 



Agassiz had promised himself that the first 

 volume of his new work should be finished in 

 time for his fiftieth birthday, a milestone 

 along the road, as it were, to mark his half 

 century. Upon this self-appointed task he 

 spent himself with the passion dominated by 

 patience, which characterized him when his 

 whole heart was bent toward an end. For 

 weeks he wrote many hours of the day and a 

 great part of the night, going out sometimes 

 into the darkness and the open air to cool the 

 fever of work, and then returning to his desk 

 again. He felt himself that the excitement 

 was too great, and in proportion to the strain 

 was the relief when he set the seal of finis on 

 his last page within the appointed time. 



His special students, young men who fully 

 shared his scientific life and rewarded his gen- 

 erosity by an affectionate devotion, knowing, 

 perhaps, that he himself associated the com- 

 pletion of his book with his birthday, cele- 

 brated both events by a serenade on the eve 

 of his anniversary. They took into their con- 



