Prof. Meyen on the Progress of Vegetable Physiology. 435 



formed. The history of its properties has been so well given 

 in Rose's Memoir, that it is unnecessary for me to do more 

 than mention my results as having been confirmatory of his. 

 This compound is decomposed by water giving white preci- 

 pitate and sal-alembroth, as may be at once seen : 



4 (2 CI + Hg) + 4 NH 3 = 



{(2Cl-rHg)+(2NH»+Hg)}+ 2 <[(2C1+Hg)+(C1+NH<)} 



[To be continued.] 



LVII. A Report of the Progress of Vegetable Physiology 

 during the Year 1836. By J. Meyen, Professor of Botany 

 in the University of Berlin.* 



[Continued from p. 390.] 



On the Combination, Structure, and Contents of the Cells of 



Plants. 

 ^VJ^TYj come now to the observations which were made known 



** last year, on the combination of cells in the higher and 

 lower orders of plants. Mohl f endeavours to establish the 

 opinion that the tissue of plants is constituted not as a col- 

 lection of contiguous cells grown together without any inter- 

 mediate substance, but that there is present a homogene- 

 ous substance, an organic mucus, in which the cells are im- 

 mersed, and by which they are connected with one another. 

 This combining substance Mohl calls intercellular substance, 

 and the discovery of it appears of such importance, that a learn- 

 ed botanist lately observed, that with it a new aera for vegeta- 

 ble physiology had arisen. Mohl \ had previously mentioned 

 this notion in his observations on the structure of the pollen 

 membranes, which Mirbel § opposed with very powerful argu- 

 ments. In the above memoir, Mohl endeavours to weaken the 

 arguments which Mirbel had advanced against his view on the 

 combination of the cells of plants; and demonstrates a so- 

 called intercellular substance, not only in the membranes of 

 the pollen, but even in various families of Cryptogamia, as 

 also in the tissue of the higher plants ; but in what degree he 



* From Wiegmann's Archiv fur Naturgeschichte, 1837, Part 3. Trans- 

 lated by Mr. Wm. Francis. 



f On the Combination of the Cells of Plants with one another. Published 

 as an Inaugural Dissertation in September 1835. It was then again printed, 

 enlarged, under the title of: " Explanation and Defence of my view of the 

 Structure of Vegetable Substance," with 2 plates. Tubingen 1830. 



J Vide Meyen's Year's Report for 1834, p. 153. 



§ Ibid., 1835, p. 101. 



3 K2 



