No. 2, September, 1920] PHYSIOLOGY 287 



METABOLISM (ENZYMES, FERMENTATION) 



2193. Andre, G. Sur l'inversion du sucre de canne pendant la conservation des oranges. 

 [The inversion of sucrose in oranges during storage.] Compt. Rend. Acad. Sci. Paris 170: 126- 

 128. 1920. —Oranges were cut in two, one-half being analyzed at once for the amounts of citric 

 acid, sucrose, and invert sugar present. The other half was deposited in a container in which 

 was also placed a small vessel of toluene, and an analysis was made of this portion after an 

 interval of 4 or 5 months. From 11.65 to 57.33 per cent of the sucrose originally present is 

 changed during this period to invert sugar. The amount of citric acid remains about the same 

 during the interval, although specimens differ in the original amount. The rate of inversion 

 is more rapid at certain times during this period than at others. The rate of inversion of 

 sucrose by citric acid was also determined in vitro at the concentrations obtaining in the ex- 

 pressed orange juice. 94.08 per cent of the sucrose is inverted in 78 days. The rate is thus 

 faster in vitro than in the orange tissue. The variations in the rate of inversion within the 

 tissue are explicable on the basis of lack of homogeneity. It does not appear that the rate 

 of inversion is affected by the amount of acid present. — C. H. and W. K. Farr. 



2191. Anonymous. Fresh information concerning yeast. Sci. Amer. Monthly 1: 417-420. 

 1920. — Certain investigations on yeast in progress at the Berlin Institute of Fermentation 

 and at the Mellon Institute at Pittsburgh are described. — Chas. 11. Otis. 



2195. Euler, H. v., and E. Moberg. Invertase und Garungsenzyme in einer Oberhefe. 

 (Invertase and ferment enzymes in surface yeast.] ArkivKemi, Min., Geol. 7 12 : 1-17. 1918-19. 



2196. Euler, Hans v., and Olof Svanberg. Enzymchemische Studien. [Enzyme 

 chemistry.] Arkiv Kemi, Min., Geol. 7 11 : 1918-19. 



2197. Giaja, J. La levure vivante provoque-t-elle la fermentation du sucre uniquement 

 par sa zymase? [Does the living yeast cell induce fermentation merely by zymase?] Compt. 

 Rend. Soc. Biol. 82: S04-S06. 1919. 



2198. Grigaut, A., F. Guerin, and Mme. Pomm ay-Mi chaux. Sur le mesure de la 

 protSolyse microbienne. [Estimation of microbic proteolysis.] Compt. Rend. Soc. Biol. 82: 

 66-70. 1919. 



2199. Hammer, B. W. Studies on formation of gas in sweetened condensed milk. Iowa 

 Agric. Exp. Sta. Res. Bull. 54: 211-220. 2 fig. 1919. — Gas formation in sweetened condensed 

 milk was found to be due to a budding organism Torula lactis-condensi . There was a variation 

 in different brands of condensed milk in their susceptibility to fermentation with the yeast 

 studied. The milk solids may retard the growth, since the yeast may grow in a saturated 

 sucrose solution. — Florence Willey. 



2200. Harvey, R. B. Apparatus for measurement of oxidase and catalase activity. Jour. 

 Gen. Physiol. 2: 253-254. 1920. 



2201. Herissey, H. Sur la conservation du ferment oxydant des champignons. Pres- 

 ervation of the oxidizing ferment of fungi.] Compt. Rend. Soc. Biol. 82: 798-800. 1919. 



2202. Kopeloff, Nicholas, S. Byall, and Lillian Kopeloff. The effect of concen- 

 tration on the deteriorative activity of mold spores in sugar. Louisiana Planter and Sugar Man- 

 ufacturer 64: 270-271. 1920. — Spores of Aspergillus sydowi, Aspergillus niger, and Penicil- 

 lium expansion are responsible for some of the deterioration of sugar and sugar products. 

 This deterioration increases with a decreased concentration of the molasses or of the films 

 around the sugar crystals. — C. W. Edgcrton. 



2203. Kopeloff, Nicholas, and Lillian Kopeloff. The deterioration of manufac- 

 tured sugar by molds. Louisiana Planter and Sugar Manufacturer 63: 202-206. 1919. — The 



