62 
the Dicotyledons. It was found necessary at this point to bring the 
undertaking to a close, “ne tertiam botunicorum generationem oe- 
 cideret!” The eight genera of Dicotyledons most numerous in 
species are: Solanum, 915; Euphorbia, 751; Senecio, 601; Cro- 
ton, 461; Phyllanthus, 447; Erica, 429; Salvia, 410; Peperomia, 
389. Next tc the elder De Candolles, J. Muller and G. Bentham 
contributed most, and next to these, C. F. Meissner and Dunal. 
The last ten volumes contain, in fact, not a mere revision but a 
complete set of monographs. In the second pamphlet, the author 
reviews the general works of descriptive botany, which have 
already appeared, and offers some thoughts on what method 
is to be pursued hereafter. He recognizes the need of a more 
profound microscopical study of the structure and evolution 
of plants, which the advanced state of the science demands. He 
thinks that, by distributing the task among twenty-five botanists, 
the Phanerogams, estimated at 110,000 species, might be described 
in about fifteen or sixteen years. In twenty or thirty years from 
this time, we shall approximate so nearly to a complete knowledge 
of flowering plants (at least Dicotyledons) as to make a new 
description desirable. In the mean time he recommends the publi- 
cation of good monographs. His father instituted a quinqujennial 
prize of 500 francs for the best monograph of a genus or a family 
of plants. The next prize will be decreed in September, 1874. The 
Club is indebted to the distinguished author for these publications. 
3. Botanical Contributions to the Proceedings of the 
Am. Acad. of Arts and Sciences, by Asa Gray; 1873. (1) 
Characters of New Genera and Species of Plants. We have 
only room to notice: Aguilegia leptocera, var. flava, Gray, the 
golden Columbine of New Mexico, etc., recognized as a distinct 
Species with the name A. chrysantha: Pachystima Canbyi, Giles 
Co., Va., an addition to our Eastern flora: Hosackia Torreyi, first 
gathered in the Sierra Nevada by Dr. Torrey; Direa occidentalis, Cal- 
fornia, (2) Notes on Composite and Characters of certain Genera 
and Species, etc. Part 1. Thisis to a certain extent a commentary 
on Bentham’s revision of the order.—— 4. Contributions to American 
Botany, by Sereno Watson. (1) New Plants of Arizona, from the 
American Naturalist. (2) On Section Avicularia of the Genus 
Polygonum, from the American Naturalist. P. Torreyt was gathered 
by Dr. Torrey in the Yosemite Valley. (3) Revisions of the Extra- 
tropical North American Species of the Genera Lupinus, Potentilla 
and Enothera, from the Proc, of Am. Acad., 1873, with copious sy2- 
onomny and references, an important contribution on very difficult 
subjects. Dr. Allen’s variety humifusa (Vid. Bull. Vol. 1. No. 1.) 
of Gnothera fruticosa is maintained. Mr. Watson has taken a place 
among our leading botanists. The synonomy and references in this 
contribution present a model of thorough workmanship. —®- 
Circulation of Sap in Plants,by Wm. §, Clark, President of Mass. 
Agric. Coll., « mherst Record, Wednesday, Dee. 17, 1873; read at 
Fitchburg, Dec, 2nd. This is essentially an account of some highly _ 
Interesting experiments and observations, carried on for months, — 
night and day, ona great variety of trees and shrubs, particularly 
Maples, Birches, and Vines, e hope it will be published jn a 
