204 PHYSIOLOGY [Box. Absts., Vol. X, 



1345. Verkade, p. E. Uber die Angreifbarkeit organischer Verbindungen durch Mikroor- 

 ganismen. II. Mitteilung. [The susceptibility of organic compounds to the attack of microor- 

 ganisms. II.] Centralbl. Bakt. II Abt. 52: 273-280, 1920.— This is an attack upon Overton's 

 theory of the permeability of the plasmamembrane; more particularly in reference to the 

 following: That the behavior of the substances of the plasmamembrane as a solvent is parallel 

 to that of olive oil; that the solubility of a substances in olive oil is an index of its ability to 

 penetrate the plasmamembrane, and so of its narcotic effect on the cell. Verkade tested the 

 solubility of benzoic, salicylic, and cinnamic acids at 25°C. in a number of carefully refined 

 fatty oils, and he concludes that the solubility of any organic acid in an oil is not a fixed quan- 

 tity, but varies with the composition of the oil. Even with oils of similar composition, such 

 as olive, cotton seed, and cocoanut oils, the dissolving power for the acids was quite different. 

 The solubility of a substance in olive oil is an isolated fact, and offers no indication of its 

 solubilitjr in any other fatty substance. This paper does not stress, though it does refer to, the 

 described parallelism between the partition coefficients of different compounds and their 

 relation to the assimilation of certain microorganisms. — Anthony Berg. 



METABOLISM (ENZYMES, FERMENTATION) 



1346. Northrop, John H. The mechanism of an enzyme reaction as exemplified by pepsin 

 digestion. Science 53: 391-393. 1921. — Experimental data for this paper are to be found in 

 recent numbers of the Journal of General Physiology (see Bot. Absts. 8, Entries 648, 649; 9, 

 Entry 1635; 10, Entry 282). The peculiarities of general enzjTne reactions are listed. In the 

 case of pepsin digestion it has been found that these peculiarities may be quantitatively 

 accounted for on the basis of "a chemical reaction in which the pepsin as well as the protein 

 takes part." This explanation also accounts for the specificity of the pepsin action. — C. J. 

 Lyon. 



ORGANISM AS A WHOLE 



1347. KopELOFF, Nicholas, and Sterne Morse. Studies in atmospheric requirements of 

 bacteria. I. Water vapor tension. Proc. Soc. Exp. Biol, and Med. 18: 308-310. 1921.— It 

 was found that inhibition of growth of surface colonies of B. coli, B. subtilis, Staphylococcus 

 aureus, and Streptococcus hemolyticus occurred when the water vapor tension was lowered. — 

 M. M. Brooks. 



1348. KuFPERATH, H. Recherches physiologiques sur les algues vertes cultivees en culture 

 pure. T. 1 Physiological investigations on green algae grown in pure culture. I.] Bull. Soc. Roy. 

 Bot. Lelgique 54: 49-77. 1921. — The author first refers to the work already done concerning 

 the action of gelatin in high concentrations upon microorganisms, and then reports his own 

 results on the action of concentrated gelatinous media upon pure cultures of algae. It is 

 concluded that the species experimented upon react in a rather constant manner in respect to 

 concentration. Certain algae grow at practically any concentration (Chlorella luteo-viridis 

 Chodatvar.ZwiescensChodat, C. vui^ans Beyerinck, Ooc?/siissp. , 0. Naegelii A. Br., jS'h'c/iococ- 

 cus membranaefaciens Chodat, S. bacillaris Naegeli, and various others). The development is 

 better and more abundant in the lower concentrations. At the higher concentrations, 25-30 

 per cent gelatin, the following species scarcely grow at all: Hormidium flaccidu7n(KiXtz.) Braun 

 f . nitens, H. dissectum (Gay) Chodat, H . lubricum Chodat, Stichococcus lacustris Chodat, 

 Chlamydomonas intermedia Chodat, Chlorococcum viscosum Chodat, Except for /Sitc/iococcws, 

 there is within certain limits quite constantly an increase in cellular dimensions in proportion 

 to the increase in concentrations. There is in general an advantage in using weak concentra- 

 tions of gelatin for isolations and for the cultures. — Henri Micheels. 



1349. LiNDET, M. L. De 1' influence que la fonctionvegetale delalevureexerce surlerende- 

 ment en alcool, et d' une nouvelle interpretation du "pouvoir ferment." [The influence of the 

 vegetative function of the yeast oh the production of alcohol and a new interpretation of a ferment 

 capacity.] Bull. Assoc. Chimistes Sucrerie et Distillerie France et Colonies 37: 29-40. 1919. 



