Euccerpta Botanica. 185 



covers, are tied in front ; by this arrangement their thickness may 

 be varied at pleasure, which, though of no consequence in a station- 

 ary herbarium, is a great convenience in a growing collection. The 

 portfolios are placed vertically on shelves protected by glass doors, 

 and the contents of each are marked on a slip of paper fastened to 

 the back. The herbaria occupy a suite of small rooms distinct from 

 the working rooms, which are kept perfectly free from dust. 



Another important herbarium at Berlin is that of Professor Kunth, 

 which is scarcely inferior in extent to the royal collection at Schone- 

 berg, but it is not rich or authentic in the plants of this country. It 

 comprises the most extensive and authentic set of Humboldt's plants, 

 and a considerable number of Michaux's, which were received from 

 the younger Richard. As the new * Enumeratio Plantarum ' of this 

 industrious botanist proceeds, this herbarium will become still more 

 important. 



For a detailed account of the Russian botanical collections and 

 collectors, we may refer to a historical sketch of the progress of 

 botany in Russia, etc. by Mr. Bongard, the superintendent of the 

 Imperial Academy's herbarium at St. Petersburgh, published in the 



* Recueil des Actes' of this institution for 1834. An English trans- 

 lation of this memoir is published in the first volume of Hooker's 



* Companion to the Botanical Magazine.' A. G. 



XXIV. — Excerpta Botanica, or abridged Extracts translated 

 from the Foreign Journals, illustrative of, or connected with, 

 the Botany of Great Britain, By W. A. Leighton, Esq., 

 B.A., F.B.S.E., &c. 



No. 6. On the Development of the Reproductive Organs of 

 the Misseltoe (Viscuni album, Linn.). By M. Decaisne. 

 (Aim. des Sci. Nat. n. s. xiii. p. 292.)* 



The male flower of the Misseltoe begins to be visible for 

 nearly a year before its expansion. The anther is then not 

 distinguishable from the green calyx by which it is embraced, 

 except by the absence of colour, being formed of cellular 

 tissue, the meshes of which are of similar form and dimen- 

 sions. Somewhat later, in this interior and colourless por- 

 tion, are formed many lacunae, which apparently result from 

 the destruction of the cellular tissue over these points, and 

 which become filled with a mucilaginous fluid. A little 

 later still, this mucilage is observed to be composed of utri- 

 cules, w ith soft, very thin and transparent walls, consider- 

 ably larger than the utricules of the adjacent parts, and con- 

 nected solely by a viscous fluid. At this time the anther 

 is constituted of three kinds of cellules ; viz. the primi- 



* [Prof. Meycn's remarks on this paper will be found at p. 169 of the pre- 

 sent Nvuiiber. — Ed.] 



