ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 181 



into the cell-membranes; but otherwise the alkaloids are always dis- 

 solved in the cell-sap of living cells ; or, in older cells of the secondary 

 cortex, occur as solid amorphous bodies. They often form a combination 

 with tannin ; the raphid-cells never contain alkaloids. They are present 

 in the largest quantity in tbe cortex. 



The author was led by his observations to the conclusion that the 

 seat of formation of the cinchona alkaloids is the leaves, whence they 

 travel to the stem, and are tbere stored up, either in their original form, 

 or after transformation into some other alkaloid. They are not the 

 result of the decomposition of proteids, but are formed by direct syn- 

 thesis from the reaction of cinchonic acid on ammonia or some compound 

 of ammonia. 



Production of Transitory Starch.* — According to J. Griiss, sucrose 

 is the first carbohydrate utilised in the germination of barley, the starch 

 not being used until the embryo reaches a certain stage, and is able to 

 furnish the enzymes necessary for rendering the starch available. The 

 rootlet is enclosed in a gum which probably consists of galactans ; this 

 contains a liquefying enzyme. 



Origin of Tannin in Galls.f — According to H. Kraemer, the crystal- 

 line substance found in the galls of Quercus coccinea (probably produced 

 by Cynips aciculata) is not tannic, but gallic acid. It appears to be 

 formed at the expense of the starch during the chrysalis stage of the 

 insect. With the maturing of the winged insect this is transformed 

 into tannic acid. The transformation of gallic into tannic acid appears 

 to be a simple process of the combination of two molecules of the former 

 with loss of one molecule of water, according to the equation 2C 7 H 6 5 = 

 C iJI 10 O 9 -f- H 2 0. 



Influence of Carbonic Acid on Fermentation. J — Dr. H. Ortloff 

 draws the following general conclusions from his investigation as to the 

 influence of cax-bonic acid on fermentation. On the inverting power of 

 certain yeasts this influence is sometimes accelerating and sometimes 

 retarding. The fermentation of dextrose is apparently rendered more 

 difficult. When fermentation takes place in a current of C0 2 , less 

 alcohol is formed, not only the absolute quantity but the quantity re- 

 lative to the amount of sugar consumed. On the production of acid the 

 action of carbonic acid is not decisive either way. The energy of cell- 

 increase is diminished, and with two exceptions the power of increase 

 also. The fermentation energy is diminished, but the fermentative power 

 is almost invariably notably increased. The individual cell exposed to 

 a current of C0 2 forms more alcohol and more acid than in ordinary 

 fermentation. As far as its total effect is concerned, carbonic acid 

 apparently acts inhibitively on fermentation, though the fermentative 

 power of the yeast-cells is increased by its influence. 



Enzymes in Cheese.§ — O. Jensen, who has made an elaborate and 

 extensive investigation relative to the intrinsic enzymes in cheese, thus 

 sums up the chief results of his work. The conversion of the casein in 



* Woch. Brauerei, xvi. (1899) p. 519. See Journ. Chem. Soc, 1901, Abstr. ii. p. 33. 



t Bot. Gazette, xxx. (1900) pp. 274-6. 



t Centralbl. Bakt., 2" Abt., vi. (1900) pp. 676-82, 721-39, 753-63. 



§ Tom. at, pp. 734-9, 763-74, 791-5, 826-44. 



