No. 2, September, 1920] PHYSIOLOGY 285 



2176. Mellanby, John. The composition of starch. I. Precipitation by colloidal iron. 

 II. Precipitation by iodine and electrolytes. Biochem. Jour. 13 2 : 28-36. 1919. — A detailed 

 account is given of the effects produced by colloidal iron and by iodine, in the presence and 

 absence of electrolytes, on a solution of potato starch in water. The results indicate that, 

 while starch grains are composed chiefly of amylogranulose, they contain various polymers 

 ranging in complexity from amylodext rin to amylocellulose ; however, the r< lative quant it i( -s 

 of the dextrin and the cellulose compounds arc small. — It. II'. Webb. 



2177. Molliard, Mabin. Influence de certaines conditions sur la consommation com- 

 pared du glucose et du levulose par le Sterigmatocystis nigra a partir du saccharose. [The in- 

 fluence of certain conditions on the comparative consumption of glucose and levulose (derived 

 from inversion of saccharose) by Sterigmatocystis nigra.] Compt. Rend. Acad. Sci. Paris 

 167: 1043-1046. 1918. — The ratio of consumption of glucose and levulose in a modified Rau- 

 lins' solution varies upon the addition of different quantities of HC1 and with changes in the 

 nitrogen ratio, the glucose being used more rapidly. The utilization of the two sugars appears 

 to depend on a function of the mycelium and not on the differential diffusion of the sugars. 

 — G. M. Armstrong. 



2178. Northrup, Zae. Agar-liquefying bacteria. [Abstract.] Absts. Bact. 3: 7. 1919. 

 See Bot. Absts. 5, Entry 1969. 



2179. Osborne, Thomas B., and Lafayette B. Mendel. The extraction of "fat-soluble 

 vitamine" from green foods. Proc. Soc. Exp. Biol, and Med. 16: 9S-99. 1919. — Contrary to 

 the statements of several investigators, the writers experimentally demonstrate that it is 

 both possible and practicable to obtain "fat-soluble" vitamine from green foods by mcanB 

 of ether extraction. — R. W. Webb. 



2180. Riviere, G. De la progression de la maturation dans les poires a couteau. [Pro- 

 gression of ripening in table pears.] Jour. Soc. Nation. Hortic. France 20: 306-307. 1919. — 

 See Bot. Absts. 5, Entry 1770. 



2181. Schowalter, E. Zur Titration von Zuckerarten. [Titration of sugars.] Zeitschr. 

 Untersuch. Nahrungs- u. Genussmittel 38: 221-227. 1919. 



2182. Tasaki, Buhachir6, and Ushio Tanaka. On the toxic constituents in the bark 

 of Robinia pseudacacia L. Jour. Coll. Agric. Tokyo Imp. Univ. 3: 337-356. 2 fig. 1918. — 

 The toxic constituent proved to be a glucoside and has been named "Robitin." It amounts 

 to about 1 per cent of the fresh bark. The symptoms of intoxication in animals are dis- 

 cussed. — B. M. Duggar. 



2183. Waksman, Selman A. On the metabolism of actinomycetes. [Abstract.] Absts. 

 Bact. 3:2-3. 1919. 



2184. Waksman, Selman A., and Jacob S. Joffe. Studies in the metabolism of actino- 

 mycetes. IV. Changes in reaction as a result of the growth of actinomycetes upon culture media. 

 Jour. Bact. S: 31-48. 1920. — The hydrogen-ion concentration of various media was tested 

 before and after the growth of various forms of Actinomyces with a view to determine the 

 changes in the media due to the different substances added as sources of carbon and nitrogen. 

 It was found that no appreciable amount of acid was formed from the carbohydrates studied 

 which included glucose, lactose, sucrose, maltose, mannitol, glycerol, starch, inulin, and so- 

 dium acetate. When sodium nitrate was added to the medium with the different carbohy- 

 drates, an alkaline reaction resulted; if sodium nitrite was added instead of the nitrate an acid 

 was produced. When ammonium salts of strong acids are present as the only source of nitro- 

 gen, the medium tends to become distinctly acid; with proteins and amino acids the reaction 

 may be unchanged or may become either acid or alkaline depending on the species, source of 

 carbon, and the hydrogen-ion concentration of the medium. — Chester A. Darling. 



