130 Meyen's Report for 1839 on Physiological Botany, 



XVIII. — Report of the Results of Researches in Physiological 

 Botany made in the year 1839. By F. J. Meyen, M.D., 

 Professor of Botany in the University of Berlin*. 

 [Continued from p. 35.] 



Anatomy of Vegetables, 

 M. DECAiSNEf has published a short notice on the structure 

 of the wood of the Misseltoe : he could not confirm the state- 

 ment of M. Dutrochet, who says that the woody body is 

 wanting in the articulation (Gliederung) between the inter- 

 nodes, and is only connected by a cellular layer of pith, so 

 that, properly speaking, the internodes are connected together 

 solely by the bark. According to M. Decaisne r s observations, 

 it is exactly in the internodes that the vessels of the bark are 

 separated ; and he says, that on this fact the articulation of 

 this plant depends, but not on the separation of the fibres of 

 the wood. The wood of Viscum exhibits no vessels (hereby 

 is meant simple spiral tubes. — Mey.), and only in the pith 

 were seen annular tubes ; the nerves of the leaves did not 

 possess any spirals. The number of the vascular bundles 

 (Holzbiindel) in young twigs is regularly eight, seldom seven 

 or nine, and each is surrounded, both inwardly and out- 

 wardly, with a bundle of bast cells. 



M. Dutrochetf attempted to demonstrate to the Academy 

 that his former statements were correct. 



Already in 1838 M. Morren§ had made some physiological 

 observations on a new plant named by him Malaxis Par thorn, 

 which, however, I have only lately seen. M. Morren indicates, 

 that a colouring matter similar to indigo must be contained 

 in the leaves of this plant, as in the flowers of Calanthe vera- 

 trifolia and in the leaves of Mercurialis perennis, &c. The 

 presence of indigo in the Orchidea was however discovered 

 years ago by M. Marquart in Bonn. The air-rootlets which 

 were examined by M. Morren Were covered with a quantity 

 of very fine hairs, consisting of single transparent cells, the 

 walls of which were very thin, and exhibited within a rotation 

 (cyclosis). [The universal appearance of these rotating 

 streams in the root-hairs of Phanerogams I have already 

 proved. — Mey.~\ 



M. Morren observed, that in some of these hairs the glo- 

 bules collected together in masses and formed a kind of par- 

 tition, by which the cyclosis was prevented ; indeed he be- 



* Translated and communicated by Henry Croft, Esq. 

 f De la Structure ligneuse du Gui. Comptes Rendus 1839, p. 204. 

 j Comptes Rendus, p. 215. 



§ Notice sur une nouvelle espece de Malaxis, &c. Bull, de l'Acad. de Sci. 

 de Bruxelles, torn. v. No. 8. 



