No. 423.] NOTES AND LITERATURE. 247 
A descriptive catalogue of the mollusks of Porto Rico, with 
a check list of species, has been prepared by W. H. Dall and 
C. T. Simpson (United States Fish Commission Bulletin Jor 1900, 
Vol. I, pp. 351—524, Pls. LIII-LVIII). In all, about 650 species 
are recorded, of which forty-two are new. The report is illustrated 
by excellent figures, and has a good index. 
BOTANY. 
The Yearbook of the Department of Agriculture.! — The grow- 
ing size, complexity, and activity of the national Department of 
Agriculture has led to attempts to simplify its publications by the 
establishment of series accredited to the several divisions and more 
or less closely pertaining to the nominal work of the latter; and a few 
years ago the secretary had the happy idea of confining the annual 
volume — before that called a Refort—to an administrative and 
scientific summation of the year’s work, under the title Yearbook. 
Difficulty appears to have been experienced in carrying out this idea, 
however, and the Yzaroo£ has once more approximated its former 
size and character, notwithstanding the voluminous annual aggregate 
of bulletins and circulars published from the several divisions. In 
addition to the report of the secretary and an appendix of over two 
hundred pages, collectively constituting the report proper, the Year- 
book for ri9oo includes a biographic sketch of the late William 
Saunders, for many years connected with the care of the grounds 
and plant houses of the Department, and no less than thirty special 
articles, on such subjects as Smyrna fig culture, date culture, prac- 
tical foresty in the southern Appalachians, etc. ,-——all of interest 
and value. T. 
Britton's Manual.*— The most potent means of i impressing ideas 
or facts on the public mind lies in their concrete presentation in such 
form as to insure ready accessibility and invite frequent reference. 
When, in 1892, the American botanists assembled at 
adopted a dification which involved extensive changes 

1 Yearbook of the United States Department of Agriculture, 1900. Washington, 
Government Printing Office, r90r. 888 pp., 87 pls., and numero us figs. 
?Britton, N. L. Manual of the Flora of the Northern States and Canada. 
New York, Henry Holt & Co., 1901. x + 1080 pp. 
