206 PHYSIOLOGY [BoT. Absts., Vol. X, 



1358. Tjebbes, K., en J. C. Th. Uphof. Der Einfluss des elektrischen Lichtes auf das 

 Pflanzenwachstum. [The influence of electric light on plant growth.] Landw. Jahrb. 56: 

 315-328. Fig. 10. 1921. — The experiments were made during the winter of 1919-20 in a 

 greenhouse divided into 2 parts: In the 1st part the plants were under the influence of normal 

 daj^ight; in the 2nd, under the influence of COj and daylight, also CO2 and daylight supple- 

 mented by electric light. The temperature in all cases was the same, the amount of CO2 

 admitted from the cylinders was measured with a gas meter, and the electric light was furnished 

 by bulbs of 200 candle power, burning from 10 p.m. to 6 a.m. Seeds of wheat, rye, flax, beans, 

 peas, cabbage, beets, onions, Linaria bipartita, L. reticulata, Theris coronaria, and Reseda 

 odorata germinated several days earlier when daylight was supplemented with electric light; 

 the plants were darker green; contained more chloroplasts; and generally the intercellular 

 spaces of the leaves were larger. As examples of the influence of the supplementary electric 

 light the following are for bulbous plants: Tulips, requiring 29 days to develop in daylight, 

 needed only 23 days under the conditions indicated; hyacinth 19 against 14 daj'^s; and crocus 22 

 against 13 days. Likewise twigs of Ribes rubra and Cornus mas flower sooner under electric 

 light. Among red algae, Ceramium rubrum does not develop phycoerythrin under electric 

 light; and among brown algae, Ascophyllum nodosum and Ectocarpus do not form phaeophyll. 

 —J. C. Th. Uphof. 



TOXIC AGENTS 



1359. Bettinger, et Delaval. Action des differents acides sur le Mucor vegetal. [The 

 effect of various acids on the vegetative condition of Mucor.] Bull. Assoc. Chimistes Sucrerie 

 et Distillerie France et Colonies 37: 254-261. 1920. 



1360. Chambers, W. H. Studies in the physiology of the fungi XI. Bacterial inhibition 

 by metabolic products. Ann. Missouri Bot. Gard. 7 : 249-289. 1920. — Chambers found that the 

 "growth and death of Bacillus coli in bouillon does not follow a constant curve" but depends 

 on the Ph value of that medium. The fermentable carbohj^drates of the medium are the 

 particular components which control the active acidity. "Of the products of metabolism acid 

 is the most inhibitory, checking growth slightly at Ph 5.5 and increasing in intensity to a lethal 

 concentration between Ph 5.1 and 4.9. The first inhibition on the alkaline side is noted be- 

 tween Ph 7.0 and 7.6, depending on the age of the culture and other factors. Ph 7.6 is com- 

 parable in inhibitory action to Ph 5.1. In an asparagin-CaCOa bouillon, Ph 9.5 is not 

 fatal." Other inhibitory metabolic products of dextrose are evident near the critical active 

 acidity. "No metabolic product of the nature of an 'auto-toxin' could be found." — S. M. 

 Zeller. 



1361. Ciamician, G., e C. Ravenna. Sull 'influenza dialcune sostanze organiche sullo 

 sviluppo delle piante. Nota V. [On the influence of some organic substances on the development 

 of plants. Note V.] Atti R. Accad. Lincei Roma Rend. (CI. Sci. Fis. Mat. e. Nat.) 30^: 3-7. 

 1921. — Continuing their work on the toxicity of various organic compounds on plants (see Bot. 

 Absts.5, Entry 2240; 6, Entry 1317; 7, Entries 2133, 2134; 10, Entries, 1341, 1342), the authors 

 found that butyl amine induces an albinism though less pronounced than with isoamylamine 

 and nicotine. In previous work it appeared that hydrogenation had an effect on the toxicity 

 of compounds. To test this chinolin was compared with tetrahydrochinolin, phthalic acid 

 with tetrahydrophthalic acid, and cymene with limonene. In each case the 2nd compound 

 mentioned was more harmful than the 1st. In an attempt to study the effect of the length 

 of the chain on the effect of the compound the fatty acids were taken up but no appreciable 

 differences found. Some further tests were also made to determine the effect of additional 

 methyl groups in substances in causing injuries to plants. — F. M. Blodgett. 



1362. McCall, a. G., and J. R. Hoag. The relation of the hydrogen-ion concentration 

 of nutrient solutions to growth and chlorosis of wheat plants. Soil Sci. 12: 69-77. 2 fig. 1921. 

 — Wheat plants were grown for 2 months in 4 different nutrient solutions each of which was 



