1 68 The Smithsonian Institution 



V. 



It would be interesting to dwell upon the details of his 

 work, but his life was so full of interests that it is only by- 

 careful condensation that even an adequate outline of its 

 eventful features can be presented in this volume. 



There were several distinct activities in his career, dis- 

 tributed somewhat as follows: (i) a period of twenty-six 

 years (1843-69) devoted to laborious investigation of the 

 vertebrate fauna of North America; (2) forty years (1840-80) 

 of continuous contribution to scientific literature, of which at 

 least ten were devoted to scientific editorship ; (3) four years 

 (1846-50) devoted to educational work; (4) forty-one years 

 (1846-87) devoted to the encouragement and promotion of 

 scientific enterprises, and the development of new workers 

 among the young men with whom he was brought into con- 

 tact ; (5) thirty-seven years (1850-87) devoted to adminis- 

 trative work as an officer of the Smithsonian Institution and 

 in charge of the scientific collections of the government — 

 twenty-eight years (1850-78) its principal executive officer 

 and nine years (1878-87) the Secretary and responsible 

 head of the Institution; (6) sixteen years (i87i-'87) as head 

 of the United States Fish Commission, a philanthropic labor 

 for the increase of the food supply of the world, and inciden- 

 tally for the promotion of the interests of biological and phys- 

 ical investigation. 



VI. 



The published list of his writings contains over one thousand 

 titles. Although very many of these are brief notices and 

 critical reviews, and a considerable number are reports and 

 other official publications, there still remain two hundred 

 which are formal contributions to scientific literature. 



