No. 3, April, 1921] PHYSIOLOGY 317 



exposed from 7 to 19 hours, and the other from 19 to 7 hours with no difference whatever 

 between the two lots); (4) to light from 7 to 13 hours and to darkness from 13 to 7 hours; 

 and (5) to light from 13 to 7 hours and to darkness from 7 to 13 hours. — The experiments in- 

 cluded the following species. Hepatics: Conocephalus conicus, Lunularia cruciata, Marchan- 

 tia polymorpha, M. emarginala, Pellia epiphylla, P. endiviaefolia. Lycopodineae: Selagi- 

 nella helvetica. Phanerogams: Notoscordurn fragrans, Sempervivum tectorum, Aegopodium 

 Podagraria, Lysimachia Nummularia, L. Nximmularia var. aurea, Vinca minor, Glechoma 

 hederaceum, Ajuga reptans, A. reptans var. atropurpurea, Campanula persicifolia.— Nothing 

 was observed which showed the least difference between the effects of continuous and dis- 

 continuous illumination. In none was the structure or the form of the leaves developed in 

 constant illumination similar at all to that of those produced in darkness. Illumination of 

 24 hours of the day, of 18 hours, of 12 hours, and of 6 hours act in general in the same manner 

 upon the assimilatory organs. The influence of light upon the form and structure and also 

 upon the production of chlorophyll depends therefore much more upon its intensity than upon 

 its duration. In the majority of the experiments a light of 400 candle power at a distance 

 of 1 meter was sufficient. — Henri Micheels. 



2170. Negri, G. Su un musco cavernicolo crescente neU'oscurita assoluta. [A moss 

 growing in absolute darkness.] Atti R. Accad. Lincei Roma Rend. (CI. Sci. Fis. Mat. e Nat.) 

 V, 291; 159-162. 1920. — A moss identified as Isopterigium Muellerianum (Schor.) Lind. is 

 described and reported to have been collected by MartinoMaccagno in the grotto of Trebi- 

 ciano (Triest) in the Lindner cavern at a depth of 275 meters. The entrance is so narrow and 

 crooked that light does not penetrate to this depth. Other cases of plants growing in partial 

 or complete darkness are review^ed. — F. M. Blodgett. 



2171. WiESSMANN, H. Einfluss des Lichtes auf Wachstum und Nahrstoffaufnahme beim 

 Hafer. [Influence of light on the growth and the absorption of nutrient salts in the oats.] 

 Landw. Jahrb. 35: 183-190. 1919.— The difference in the light received by oat plants stand- 

 ing (1) on a roof and (2) in a court caused differences in yield and in the quantities of nutrient 

 salts absorbed. The oats on the roof stooled better, had stronger stalks, blossomed and rip- 

 ened earlier, and yielded more of both grain and straw than the plants in the court. The 

 percentage of nitrogen, potash, and phosphoric acid was much greater in the plants grown 

 in the more diffuse light, i.e., in the court, but the absolute amounts were much less.— vl. J. 

 Pieters. 



TOXIC AGENTS 



2172. Bertrand, Gabriel, et Mme. Rosenblatt. Action de la chloropicrine sur quel- 

 ques fermentations bacteriennes. [The effect of chloropicrine on bacterial fermentations.] 

 Compt. Rend. Acad. Sci. Paris 170: 1468-1471. 1920.— This is a study of lactic acid fer- 

 mentation, ammoniacal fermentation, and the fermentation of sorbose in relation to the 

 presence of chloropicrine. It was found that there is a distinct toxic effect which is compar- 

 able in some cases to that of the more powerful antiseptics. — C. H. Farr. 



2173. Maquenne, et Demousst. Un cas d'action favorable du cuivre sur la vegetation. 

 [An instance of the favorable effect of copper on vegetation.] Compt. Rend. Acad. Sci. Paris 

 170: 1542-1545. 1920.— Lettuce, peas, and wheat were grown in culture solutions at low 

 temperature and in w^eak light. Lettuce lived 33 days; wheat and peas 9 days. To other 

 solutions copper sulphate was added to the extent of 0.02 to 0.2 mg. per liter. The presence 

 of copper increased the length of life in all cases and the dry weight in some instances.— 

 C. H. Farr. 



2174. Medes, Grace, and J. F. McClendon. Effect of anesthetics on various cell activi- 

 ties. Jour. Biol. Chem. 42 : 541-568. 1920.— The plant used was Elodea, and the anesthetics, 

 alcohol, ether, chloroform, and chloretone. The cell activities tested were (1) consumption 

 of O2, (2) liberation of CO2 as measured by Ph changes in the solutions, (3) rotation of chloro- 

 plasts, (4) photosynthesis, (5) diffusion of chlorides from the cell. Increase or decrease in 



