Page:Journal of botany, British and foreign, Volume 9 (1871).djvu/404

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376
PROCEEDINGS OF SOCIETIES.

and so on, setting up the permanent axis of the plant from a bnd which thus originates from the very base of a well-developed radicle, if not from the root itself.—Dr. Asa Gray in Sillmans's Journal, July, 1871.

Proceedings of Socities.

Linnean Society.November;- 16th. — G. Benthain, Esq., President, in th chair. — Mr. Jansen exhibited specimens of Centanrea solstitalis found in a cornfield above Combe Martin, North Devon. " On the Floral Structure of Impatieus fulva, Nutt., with special reference to the closed self-fertilized flowers," by A. W. Bennett. These have been, on the whole, well described and drawn by Professor Asa Gray in his 'Genera of the Plants of the United States,' but the author had ob- served one or two additional points. In the ordinary conspicuous flowers self-fertilization is absolutely prevented by a membranous wing attached to the staminal tube, which completely covers in the pistil, pre- venting the access of pollen, and they seldom bear fruit. The minute closed flowers are far more numerous, and are almost invariably fertilized. The regular calyx and corolla are thrown off from the pistil in the form of a cap, resembling the calyptra of a Moss, which the author suggested is caused by the elasticity of the filaments. The stamens are of an altoge- ther different construction from those in the conspicuous flowers, entirely free, strap-shaped in form and with small anthers, containing a very small quantity of pollen. These never dehisce ; but, as is often the case with " cleistogenous " flowers, the pollen grains protrude their tubes while still in the anther, piercing its wall to reach the stigma. The " cleisto- genous " flowers are more numerous than the conspicuous ones in the proportion of at least twenty to one, and are produced throughout the summer synchronously with them, generally on different plants, occa- sionally on different branches of the same plant, never on the same branch. The author was unable to detect that the conspicuous flowers are ever visited by insects, and the staminal arrangement seemed to promote abso- lute sterility rather than cross-fertilization. The paper concluded with some observations by Mr. Darwin, generally in accordance with those of Mr. Bennett, and especially on the point that the two kinds of flowers are distinct from the outset, and that the closed ones are not the result of " arrested development," as held by Professor Gray. The paper was illustrated by a series of drawings. Mr. Beutham referred to the closed flowers of Viola, and noticed similar conditions in Ononis minutissima and Salvia clandestina; in the former of these two, the apetalous flowers, however, appear before the normal ones. " Remarks on Dolichos uniflorus," by N. A. Dalzell. " Florae Hongkongensis Suppleraentum," by H. F. Hance, Ph.D. The author adds seventy-five species to the published Hongkong Flora. The President remarked on the peculiar richness of the flora in number of species, and the interest attaching to several which have become known only through single specimens, or mere fragments accidentally obtained.