His scientific work marks an epoch in the history of American botany. 

 Entering the field at a time when the labor of Michaux, Prush, Nuttall, 

 Elliott, and others, had placed their science upon a fairly firm foundation 

 for the older States, while the great interior of the continent was as yet 

 entirely unknown, it fell to his lot to largely guide the botanical explora- 

 tion of one section after another, and to perform the severe task of elabo- 

 rating and describing the large collections that were brought in. So oner- 

 ous was this labor that it formed his chief occupation for half a century, 

 and so thoroughly well has it been done that future students must start 

 from his work as a foundation in any study of the botany of North Amer- 

 ica; while the enormous herbarium upon which his work was done, and 

 which was generously donated to Harvard University many years ago , 

 will, it is to be hoped, long preserve the evidence upon which his con- 

 clusions were based. 



Early in his botanical career, in connection with his friend and teacher, 

 the late Dr. Torrey of Columbia College, he entered upon the task of pub- 

 lishing a Flora of North America, little knowing at first that his life must 

 be given to the preliminary working out of new material before its com- 

 pletion could be seriously contemplated. In his later years, when this 

 preliminary work had been largely finished, it was still his hope to see 

 such a Flora brought out, though he realized that he could hardly expect 

 to cany the undertaking to a conclusion unaided. Unfortunatelj' for sci- 

 ence the work is now, at his death, only about one-third done, and if it is 

 completed it must be by other hands. Yet it should be added that the 

 part already published includes the large and difficult order Comfositce., 

 of which he was especially a master. 



Though a systematic botanist, trained to the traditions of the early part 

 of the century, Dr. Gray was a man of broad views and large information, 

 and his keen insight and sound judgment placed him foremost among 

 American adherents of Darwin's theory of the mutability of species, and 

 enabled him to keep well abreast of the progress made in those branches 

 of natural science with which he was less directly'concerned. For many 

 years he has occupied the unquestioned position of a leader in botanical 

 matters, to whom all looked for just approval or condemnation. A man 

 of warm impulses, the kindest of approvers, and the most exact of critics, 

 he was, withal, far too thorough in his scientific habits to allow personal 

 likes or dislikes to bias his judgment of the work of others ; while his own 

 research was always carried on in the unassuming spirit of a master. 



Notwithstanding the duties of an active professorship, which he held 

 for about thirty years, and his unceasing original investigations, he found 

 time to give thought and labor to scientific undertakings far removed from 

 the sphere of his own work. For some years previous to his death he 

 acted as a Regent of the .Smithsonian Institution; and it is well known 

 in St. Louis that he was the trusted counsellor of Mr. Henry .Shaw in 

 planning for the botanical future of ihe garden of which this city is justly 



