ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 105 



it gradually increases and at length surpasses the latter. In propor- 

 tion as the plant grows older, the quantity of water in it increases. 

 The quantity of water transpired during twenty-four hours reaches its 

 maximum in the 15th day after germination. 



Nitrates in Plants.* — According to experiments made by MM. 

 Berthelot and Andre on a large number of plants, the formation of 

 nitrates at certain spots of the tissue, and at certain periods of growth, 

 is a vital function of plants, dependent on the work of particular 

 cells, and is in close connection with the processes of oxidation and 

 reduction. They occur in all parts of the plant, but most abundantly 

 in the stem. 



Composition of the Gases in Floating and Submerged Leaves-f— 

 MM. N. Grehant and J. Peyrou find, as the result of a number of 

 experiments on plants with floating or submerged leaves, that the 

 gases exhaled by the same plant differ to a marked extent according 

 to whether the sky is cloudy or the leaves exposed to bright sun- 

 light ; those of Potamogeton lucens gave, in the former case, 3-6 per 

 cent., in the latter case 6 • 9 per cent, of oxygen. 



Amphid-Substances in the Sap of Plants. J— According to Herr 

 C. Kraus, there are in the sap of plants, in addition to acid and alka- 

 line, a number with amphid-reaction. This he has determined by 

 experiment on the saj) of the medullary parenchyma of more than 20 

 species. 



Elimination of Oxygen from Plants. § — Prof. N. Pringsheim 

 describes a series of experiments with the micro-spectrum on a 

 number of different plants, both green, brown, and red, which tend to 

 show that there is no invariable coincidence between the maximum of 

 absorption of carbon dioxide and the maximum of elimination of 

 oxygen. 



New Alcoholic Ferment which does not Invert Sugar. || — Signor 

 J. F. Teixeira found that brews were gradually losing their character, 

 and the yeast, on examination, contained a special ferment, which it 

 was possible to isolate. The cells are globular, 0* 2-0 '33 /x broad, 

 and do not invert saccharose. 



Fermentation in the Living Sugar-cane.lf — Sigg. Palmeri and 

 Comes have observed that a process of true fermentation goes on in 

 the sap of the sugar-cane, the fermentation following the course of 

 the vascular bundles and being indicated by the dark-red colour 

 of the stem. They state that the organized ferments found in the 

 fermenting tissues are Hormiscium sacchari Bonord., which they 



* Journ. rharrn. et Chim., 1884. See Bot. Centralbl., xxiii. (1885) pp. 274 

 and 275. 



t Coinptes Eendus, ci. (1S85) pp. 485-6. 



% Ber. Deutsch. Bot. Gesell. Generalversainmluug, 1885, pp. xx.-xxvi. 



§ Ibid., pp. Ixxii.-lxxx. 



11 Jouru. Chem. Soc. — Abatr., xlviii. (1885) p. 1168, from Bied. Coutr., 

 1885, pp. 416-7. 



^ Reud. R. Aecad. Sci. Fis. e Mat. Napoli, 1883. Sec Bot. Ccutralbl., xxiii. 

 1SS5) p. 19. 



