1886-87.] in regard to tlte Vegetable Cell-Wall. 41 



sequence of an extremely interesting work by Wiesner * 

 which has recently appeared, and which throws an entirely 

 new light upon the question. Wiesner finds that the micro- 

 somes noticed by Strasburger and Schmitz (which he calls 

 dermatosomcs) are not only present in the earliest state, but 

 can be detected in it by appropriate treatment,! always or at 

 least so long as it continues to grow. They are organised 

 bodies of protoplasmic nature, and take an active part in 

 the formation of the cell- wall. Klebs| has recently attacked 

 this view. He looks upon these dermatosomes as being 

 products of disorganisation of the cell- wall, but, as Mikosch§ 

 has already pointed out, this can hardly be maintained if we 

 consider that the same bodies are produced by different 

 reagents, some of which are not strongly destructive. The 

 interesting part of Wiesner's theory, however, consists in his 

 statement that not merely the microsomes, but the delicate 

 network of protoplasm || (c/. Schmitz, loc. cit.), by which they 

 are held together during wall-formation, persists within the 

 cell-wall, at least so long as it continues to grow. Each 

 lamella consists of a layer of microsomes in this protoplasmic 

 network ; and its protoplasm is connected both with that of 

 other lamellae and with the protoplasm of the cell by delicate 

 protoplasmic strings. If this is accepted, the cell- wall must be 

 considered as a living part of the plant, a theory which w^ould 

 explain much at present contradictory. In support, Wiesner 

 states that, in young cell-walls, the ordinary cellulose reaction 

 can only be obtained after treatment with caustic potash, which 

 he considers dissolves these protoplasm strings. He has been 

 confirmed, so far as the fact goes, by Schaarschmidt.^ Stras- 

 burger has also obtained the alkali-silver (solution A ? of Loew 

 and Bokorny) reaction for living protoplasm in the cell- wall of 

 Spirogyra.** Wiesner also found that the hyphte of Polyporus 



* Wiesner, Sitz. d. k. Akad. IViss. Wicn, Abt. i., 1886. 



t He gives three methods (best material, cotton-wool fibres) : — (a) Treat with 

 chromic acid ; or [b) for a week in chloral water, and then press gently on 

 the cover-glass ; or (c) first 20 minutes in 2 per cent, hydrochloric, then in 

 concentrated hydrochloric, and press on the cover-glass. 



+ Klebs, Biologische Centralblatt, Bd. vi., 1886, p. 449. 



§ Mikosch, Botanische Centralblatt, Bd. xxviii., 1886, p. 228. 



II Wiesner, loc. cit.; cf. also Fromman, Jena Zeit., xviii., 1885. 



f Schaarschmidt, see £ot. Centralblatt, xxii., 1885, p. 3. 



** Strasburger, loc. cit., p. 68 ; cf. also Loew and Bokorny, Chemis. Kraft- 

 quell e im Leb. Prot., Munchen, 1882, p. 51. 



