Dr. M even's Researches in Physiological Botany, 143 



By the action of concentrated sulphuric acid the primitive 

 membrane was converted into dextrin and sugar, and in this 

 manner the sclerogene was separated. 



Finally, M. Payen has published a treatise on the different 

 states of aggregation of vegetable tissues*. The substance 

 which forms the cellular membrane is said to be in a pure state, 

 but in a less firm state of aggregation, in starch. He has ex- 

 amined the membranes of several of the lower plants, which 

 are nearly allied to the above-mentioned substance in their 

 chemical and physical properties. The first comes to the con- 

 sideration of the appearance of starch in lichens, and arrives 

 at the same results as have already been made known in a 

 former Report, viz. that the cellular membranes of lichens are 

 coloured blue by iodine, and that in such plants it is these 

 which dissolve to a jelly. On this occasion M. Payen remarks 

 that he has analysed the spiral vessels of Musa, and has 

 found their composition similar to that of other membranes f. 

 Moreover he analysed the purified membranes of the threads 

 of Rivularia which support the spores, and found it of the 

 same constitution as starch. In the same way the tissue of 

 mushrooms was analysed, after careful purification, and found 

 to be a substance isomeric with the membranes of other plants ; 

 the same was found with the membrane of Chara. Finally, 

 M. Payen directs attention to the fact, that the vegetable cel- 

 lular membrane is only a ternary compound, while the qua- 

 ternary organic compounds are found among the animal tis- 

 sues ; and although many parts of plants abound in nitrogen, 

 still this body is only found in the contents of the cells. 



M. Payen has also made known his views concerning the 

 Nutrition of plants {. The cambium appears at first as agra- 

 nular contractile substance, containing nitrogen. This sub- 



* " Memoire sur les etats differens d'aggregation du tissu des Vegetaux." 

 — Comptes Rendus de 26 Aout, 1839, p. 296. 



f " An ultimate analysis of the spiral fibres of Musa paradisiaca was made 

 in the year 1838, by Prof. Mitscherlich and myself, (vide Meyen's Pflanzen 

 Physiologie, ii. p. 551, and English translation of Meyen's Report for 1837, 

 p. 26) which, however, gave quite a different result : microscopical observa- 

 tions show that these spiral fibres may be compared with the secondary cel- 

 lular membranes, and therefore they must have a similar composition to 

 that of Payen's sclerogene, if indeed his apparently so correct analyses may 

 be fully trusted." — Meyen. 



% " Memoire sur la nutrition des Plantes." — Comptes Rendus, de 21 Oct. 

 p. 509. 



