ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 995 



constructs the albuminoids of its protoplasm out of amido-compounJs, the 

 formation of amido-acids is a vcrj important item in the processes of 

 metastasis. 



Theory of Fermentation.* — Herr N. W. Diakonow has published the 

 first part of a detailed account of his investigations on " the role of the 

 fermentable nutritive substance in the life of the vegetable cells." His 

 results will be summarized wlien his memoir is completely published. 



He gives a clear historical introduction, resuming the pi-ogress of 

 investigation in regard to fermentation from the researches of Thenard 

 onwards. The various theories are briefly stated and compared. 



The point on which his own researches were first concentrated was that 

 of the influence of the composition of the nutritive substances transformed 

 by the fungus on the nature of the gaseous transformations effected in the 

 surrounding medium. The nature of the gaseous exchange with the exter- 

 nal medium, as determined by the fungus, varies according to the chemical 

 composition of the nutritive substances taken in, and differs of course 

 markedly from what takes place in a simple combustion of the same 

 substances. The relation between the quantity of oxygen absorbed and 

 carbonic acid gas given off is determined by the proportion of oxygen in 

 the nutritive substance. The author has sought to determine what relation 

 obtains between the intensity of the liberation of carbonic acid in the absence 

 of atmospheric oxygen and the quantity of oxygen in the nutritive material. 

 The nutritive substances used were glucose, lactose, chiuic acid, and tartaric 

 acid. The fungi experimented on were Penicillium glaucum, Aspergillus 

 niger, and Mucor stolonifer. A detailed description is given of the 

 methods of research. 



Alcoholic Fermentation.f — Prof. F. Delpino contests the modern view 

 that the process of the fermentation of grape-sugar is a complicated one, 

 in which succinic acid and glycerin are produced. These substances he 

 believes not to be the direct products of fermentation, but, when foimd in 

 the fermented liquid, to be degraded substances resulting from processes 

 connected with the plastic or proteinaceous nutrition of the saccharomycete. 

 He reverts to the older view that the effect of the ferment is to decompose 

 the sugar directly into alcohol and carbon dioxide. 



Prof. Delpino proposes to unite the forms known as Saccharomyces 

 cerevisise, minor, and ellijjsoideus, into a single species with the name 

 S. zymogenus. 



Chemical nature of Diastase.^— Dr. C. J. Lintner contests Hirsch- 

 feld's statement that vegetable diastase is a special molecular modification 

 of a particular germ. He asserts, on the contrary, that it contains nitrogen, 

 and presents many points of similarity to the albuminoids, although it 

 cannot be included under this group of substances. A more exact com- 

 position he is not able to give. 



y- General. 



Adaptation of Plants to rain and dew. §— Prof. N. Wille records 



the results of a series of experiments for the purpose of determining 



the extent to which jjlants can absorb moisture through their aerial organs. 



The experiments were made on a number of species, by placing on them 



* Arch. Slav. Biol., iv. (1887) pp. 31-61. Cf. this Journal, ante, p. 619. 

 t Nuov. Giorn. Bot. Ital., xix. (1887) pp. 260-2. 

 X Pfliiser's Arch. f. Ges. Physiol., 1887, pp 311-4. 



§ Cohn's Beitr. z. Biol. d. Filanzen, iv. (1887) pp. 285-321. Cf. this Journal, ante, 

 p. 119. 



