Miscellanies. 205 



Wednesday/, Feb. 19. — R. H. Solly, Esq. in the chair. A paper was 

 read by Mr. Q,ueckett, on the development of the vascular tissue of plants, 

 in which it was shown that the membranous tube of vessels originated 

 from a cytohlast in a manner similar to that described by Schleiden in 

 the formation of cells, from which it is at first difficult to recognize them ; 

 but in a short time, they assume a very elongated form, and the cytohlast 

 disappears. Before the fibre is deposited, the contents, which are gela- 

 tinous, are crowded with numerous most minute granules, which possess the 

 motion known as that of " active molecules," and after a short time, when 

 they have become a little enlarged, they adhere to the inner surface of the 

 tube containing them in a different manner for each vessel ; so that the 

 several varieties of vascular tissue are not degenerations of each other, 

 but are constructed originally on the plan they are always observed to pre- 

 sent to the eye. 



It had been conjectured by Schleiden that a current existed between 

 the gelatinous contents of the cell and its walls, which preceded the for- 

 mation of a fibre, and gave the direction it afterwards took ; this was re- 

 futed by showing that the granules became separately attached to the in- 

 side of the vessel, at a little distance from each other, beginning first at 

 one end and proceeding to the opposite, the fibre elongating like a root, 

 by the materials of growth being always added to the point. The gran- 

 ules so attached, becoming nourished by the contents of the vessel, and 

 the spaces between them are in a short time obliterated by the fibre 

 occupying a defined border, which completes its development. [The va- 

 ried manner in which the granules are deposited, so as to produce all the 

 varieties of vascular tissue, is explained in the remaining portion of the 

 abstract of Mr. Queckett's paper.] — From the Annals of Natural History 

 for March, 1840. 



31. On the remarkable diffusion of Coralline Animalcules from 

 the use of Chalk in the arts of life, as observed by Ehrenberg. — ^An 

 examination of the finest powdered sorts of chalk which are used in 

 trade, has afforded Prof. Ehrenberg the following result : that even 

 in this finest condition, not merely the inorganic part of the chalk is 

 become separated, but that it remains mixed with a great number of 

 well-preserved forms of the minute shells of coral animalcules. As 

 powdered chalk is used for paper hangings, Prof. Ehrenberg also ex- 

 amined these, as well as the walls of his chamber which were simply- 

 washed with lime, and even a kind of glazed vellum paper called vis- 

 iting cards, and obtained the very visible result — demonstrating the 

 minuteness of division of independent organic life; that those walls 

 and paper-hangings, and so, doubtless, all similar walls of rooms, 

 houses, and churches, and even glazed visiting cards prepared in the 

 above mentioned manner, (of which cards, however, many are made 



