June, 1920] PHYSIOLOGY 427 



light seven Wratten filter screens were used; the wave lengths were determined, and a simple 

 method for measuring and equalizing intensities was devised. Fertilized eggs (if Fucu.v 

 injlatus were exposed to light of the seven wave lengths produced and also to white light. 

 An electric arc gave light of all wave lengths, but the heating effect quickly killed the spores. 

 Orientation of the first cell plate occurred in all isolated cells with light of short wave lengths 

 produced by a mercury-vapor lamp. Both intensity and wave length seemed to be factors 

 in the negative phototropism of young rhizoids. With spores germinating in close proximity 

 to each other (within about 0.2 to 0.5 mm. or less), a group orientation occurred, the rhizoidal 

 cell always being toward the center of the group. These orienting effects may be explainable 

 by Child's theory of metabolic gradients. — H. B. Frost. 



2910. Ridgway, Chakles S. A promising chemical photometer for plant physiological 

 research. Plant World 21 : 234-240. 1918.— The author suggests a solution of 1 per cent 

 uranium acetate and 5 per cent oxalic acid mixed in the proportion of 1 : 4 as a chemical 

 photometer for a study of light effects. Results of the tests were in general agreement with 

 the Callendar pyrheliometer, although the two instruments involve different portions of the 

 spectrum. The chief advantages are inexpensiveness, ease of taking readings, accuracy of 

 determinations, and automatic integration. — Chas. A. Shull. 



TOXIC AGENTS 



2911. Binger, C. A. L. The selective inhibitory action of methylene blue and certain 

 other common dyes on the growth of meningococci. Jour. Infect. Diseases 25: 277-283. 1919. 

 — Gentian violet, crystal violet, brilliant green, Bismarck brown, safranin, and methylene 

 blue, were found to have an inhibitory action upon the growth of meningococci. Basic 

 fuchsin, vital red, fluorescin, and eosin did not inhibit the growth of these organisms. On 

 comparing the inhibitory action of mercuric chloride, methylene blue, formaldehyde, and 

 phenol, the first was found to exert the most powerful action, phenol the least, the other two 

 compounds being intermediate. The growth of meningococci was inhibited by methylene 

 blue at dilutions which failed to inhibit the growth of the other organisms with the exception 

 of the gonococcus. The dilution at which methylene blue inhibited the growth of different 

 suspensions of meningococci varied with the number of viable organisms present. — Selman 

 A. Waksman. 



2912. Davis, D. J. The effect of potassium iodid on experimental sporotrichosis. Jour. 

 Infect. Diseases 25: 124-131. * fig. 1919.— See Bot. Absts. 3, Entry 1630. 



2913. DeOng, E. R. Effect of excessive sterilization measures on the germination of 

 seeds. Jour. Econ. Entomol. 12: 343-345. 1919.— This is a report of a study of the effect of 

 temperature and of different amounts of cyanide, and of carbon bisulphide, all applied for 

 various time intervals, upon the germination of seed treated to stamp out insect infestation. 

 The seed used in the tests were as follows: wheat, 5 varieties; corn, 7 varieties; barley, 2 

 varieties; oats, 1 variety; rye, 1 variety; rice, 2 varieties; peanuts, 1 variety; alfalfa, 1 va- 

 riety; peas, 2 varieties; beans, different genera and species; almonds, 14 varieties. — The 

 effect of the treatments on the bean group is given in tabular form. Results indicate that 

 beans are not so susceptible as usually supposed, if they are well cured. The common dosage 

 in fumigation and "heat sterilization" are safe practices, both for grains and legumes, with 

 proper precaution as to length of exposure and ventilation afterwards. — A. B. Massey. 



2914. Green, H. H., and N. H. Kestell. Behaviour of bacteria towards arsenic. South 

 African Jour. Sci. 15 : 369-374. 1919. — Differences in tolerance of different bacteria for arsenic 

 are very marked. Many which are fairlj' tolerant of arsenate are relatively sensitive to ar- 

 senite. Certain groups are characteristically sensitive, e.g., the subtilis group, of which the 

 four leading representatives were tested, and all found intolerant of 0.05 per cent of As 2 0.t 

 as sodium arsenite in broth. The colon-typhoid group is sensitive as a family, but has at least 



