Fkbruary, 1920] PHYSIOLOGY 67 



cell. He discusses the views of previous workers as to the origin of mucilage. — The mucilage 

 uf Opuntia is hydrolyzed by various acids and submits slowly to the digestive action of 

 organisms, gradually losing its viscosity. The effect of various stains upon mucilage was 

 studied. Some were adsorbed vigorously, others less so and others not at all. The degree 

 of adsorption is related to the degree of hydration. The viscosity of the mucilage was found 

 to be lowered by those dyes which are adsorbed, "at a rate and to an extent in direct relation 

 to the degree of adsorption." — E. W. Sinnott. 



443. Magoon, C. A., and J. S. Caldwell. A new and improved method for obtaining 

 pectin from fruits and vegetables. Science 47: 592-594. 1918. 



444. Mibandk, Marcel. Sur les reactions michrochimiques et les localizations de l'alca- 

 loide de l'lsopyrum thalictroides. [Concerning the microchemical reactions and localizations 

 of the alkaloid of Isopyrum thalictroides.] Compt. Rend. Acad. Sci. Paris 168: 316-317. 1919. 

 —See Bot. Absts. 3, Entry 430. 



445. Molliard, Marin. Production d'acide citrique par le Sterigmatocystis nigra. 

 [Production of citric acid by Sterigmatocystis nigra.] Compt. Rend. Acad. Sci. Paris 168: 360- 

 363. 1919.— Wehmer (1893) created the genus Citromyces on the basis of the fact that cer- 

 tain fungi produced citric acid under certain conditions. It was considered that this fact 

 was of significance in denoting relationship and that the production of citric acid was of the 

 same significance as the formation of oxalic acid in Aspergillus, Penicillium, and Sterigmato- 

 cystis. Experiments by the author show that conditions unfavorable to the growth of the 

 mycelium of Sterigrnalocystis nigra and especially a small amount of nitrogen compared with 

 the amount of sugar present in the substratum, result in the formation of citric acid. Both 

 oxalic acid and citric acid may appear in the same cultures or they may each appear separately. 

 Under the conditions studied much greater amounts of citric acid than of oxalic acid were 

 formed. — The conditions resulting in the formation of citric acid in Sterigmatocystis nigra are 

 the same conditions that favor its formation in Citromyces. Wehmer showed further that 

 citric acid may also be formed by Mucor pyriformis and Penicillium luteum. — The author 

 points out the danger of employing physiological characteristics in the classification of organ- 

 isms in systems where morphological characteristics are also employed. — V. H. Young. 



446. Neidig, R. E., C. W. Colver, H. P. Fishbtjrn, and C. L. von Ende. The acids of 

 silage. Idaho Agric. Exp. Sta. Bull. 104: 19-20. 1918. 



METABOLISM (NITROGEN RELATIONS) 



447. Neller, J. R. Studies on the correlation between the production of carbon dioxide 

 and the accumulation of ammonia by soil organisms. Soil Science 5: 225-241. PL 1, fig. 1-5. 

 1918. 



METABOLISM (ENZYMES, FERMENTATION) 



448. Bourquelot, Em., and M. Bridel. Syntheses biochimiques simultanees du gentio- 

 biose et des deux glucosides /3 du glycol par l'emulsine. [Simultaneous synthesis of gentiobiose 

 and of two ^-glucosides of glycol by emulsin.] Compt. Rend. Acad. Sci. Paris 168: 253-256. 

 1919. — Emulsin of almonds is apparently a mixture of at least three enzymes; viz., gentiobiase, 

 cellobiase and /8-glucosidase. Theoretically such a mixture of enzymes acting on a mixture 

 of /3-glucose and glycol in diluted solution should bring about the synthesis of four substances; 

 viz., cellibiose, gentiobiose and mono- and diglucoside of glycol. Experiments conducted 

 along these lines yielded all of these substances in crystalline form except cellobiose. — V. H. 

 Young. 



449. Bourquelot, Em., and M. Bridel. Synthese biochimique, a l'aide de l'emulsine, 

 du glucoside de l'alcool naphthylique alpha. [Biochemical synthesis of glucoside beta by emul- 

 sin.] Compt. Rend. Acad. Sci. Paris 168:323-324. 1919.— Naphthyllic alcohol (a-naphthyl- 

 carbinol) obtained by Grignard's reaction was mixed with glucose in acetone solution and to 

 the mixture emulsin was added. Changes in the rotatory power of the solution were noted. 



