Scientific News. 281 
Cyperaceæ ”) was wrought out. In the introductory note to part 
I, which bears date of February 1, 1834, acknowledgment is made 
of the author’s obligations to Torrey “ for the interest he has taken 
in his botanical pursuits, for the important aid he has rendered him 
in the determination of doubtful species, and for the use of his 
valuable library and herbarium.” 
In his twenty-ninth year Dr. Gray visited Europe, and made 
the acquaintance of many of the great botanists of that time,— 
the elder and the younger Hooker, Bentham, Greville, Robert 
Brown, Lindley, Mirbel, Decaisne, St. Hilaire, Boissier, Adrien 
de Jussieu, Endlicher, Von Martius, the De Candolles, Schlechten- 
dal, Kunth, Ehrenberg and many others. 
ree years later he was called to the chair in Harvard Col- 
lege, which he filled for thirty-one years, until relieved of the 
drudgery of teaching in 1873. When sixty years old he was 
elected president of the American Association for the Advance- 
ment of Science, at the meeting held in Troy, and two years later 
delivered his famous address, “Sequoia and its History,” at 
Dubuque. 
Upon the anniversary of his seventy-fifth birthday the botanists of 
the country united in a testimonial of respect and veneration to the 
one on all hands acknowledged to be their leader. Last year, on his — 
revisiting England and Scotland, the Universities of Oxford, Cam- 
ridge and Edinburgh, honored themselves as well as him by con- 
ferring upon him their highest degrees. 
„The activity of his mind throughout a long life may be in- , 
dicated by the following list of the more important of his pub- 
lications, with the age at which they were issued: 
At 24.—North American Graminex and Cyperacee. 
At 26.—Elements of Botany. 
At 28.—A Flora of North America (in conjunction with Dr. 
Torrey), 
At 32.—The Botanical Text-Book. 
At 36.—Chloris Boreali-Americana. Decade I. 
At 38.—A Manual of the Botany of the Northern United States. 
