524 EXPERIMENT STATION EECORD. 



Atkins (Sci. Proc. Roy. DuUi/n Soc, n. ser., U {1913), No. 2, pp. 9-12; Notes 

 Bot. School Trinity Col. Dublin, 2 (WIS), No. Jf, pp. 173-176).— In continuance 

 of studies previously reported (E. S. R., 29, p. 828), the authors found that 

 in both osmotic pressure and electrical conductivity pressed yeast gives values 

 much higher than those of wort. Bakers' yeast, however, gave a low osmotic 

 pressure but a high conductivity even after washing. On comparing the re- 

 sults given by beer with those of wort, it was noted that while the electrical 

 conductivity remains much the same, the osmotic pressure becomes approxi- 

 mately three times as great during fermentation, when interrupted at the usual 

 stage in the commercial process. Very complete fermentation, however, in 

 the single experiment carried out, occasioned a fall in osmotic pressure after 

 the initial rise and was accompanied by a marked increase in conductivity. 



Studies on the influence of electricity on plant growth, W. Schikorba 

 (Mitt. Kaiser Wilhelms Inst. Landw. Bromherfj, 5 (1913), No. 5, pp. 403-^11, 

 fig. 1). — Tests with an electrical brush discharge of high tension on the 

 development of several cereals are reported to show no very decidedly benefi- 

 cial effects on growth. The results reported by P. Vozary (E. S. R., 28, p. 326) 

 are thought to be due largely to an increase of transpiration by the electrical 

 wind attending the brush discharge. 



Influence of radio-active emanations on vegetation, J. Stoklasa and V. 

 Zdobnicky (Oompt. Rend. Acad. Sci. [Paris], 157 (1913), No. 22, pp. 1082- 

 1084)' — Presenting some quantitative results of a study with several grains, 

 legumes, etc., subjected to radio-active energj^ from different sources, the 

 authors state, in conclusion, that radio-active emanations in moderate concen- 

 trations influence favorably the development of plants and gaseous exchange 

 thereby, their flowering, and total production. Very heavy concentrations, on 

 the contrary, check the development and appear to cause or favor the forma- 

 tion of toxic substances in the chlorophyll bearing portions. 



Influence of radio-activity on micro-organisms which fix nitrogen or 

 transform nitrogen compounds, J. Stoklasa (Compt. Rend. Acad. Sci. [Paris], 

 157 (1913), No. 19, pp. 879-882).— This is a study of several nitrifying and 

 denitrifying bacteria in varied nutritive solutions subjected to the action of 

 emanations from pitchblende. The results are thought to show a considerable 

 influence of radio-activity upon the general circulation of nitrogen and to be 

 of importance in connection with the control of soil fertility. 



The study of cold resistance by cereals, G. Gassneb and C. Geimme (Ber. 

 Deut. Bot. Gesell., 31 (1913), No. 8, pp. 507-516) .—In tests with barley and rye 

 it was found that the varieties germinating at the lower temperatures showed 

 the higher sugar content, but no other marked differences of composition. 

 Winter injury to green plants is attributed to volumetric alterations rather than 

 to any i^eculiar effect on the plant cells. 



The blackening of the leaves of Aucuba japonica, S. G. Paine (Ahs. in 

 Rpt. Brit. Assoc. Adv. Sci., 1912), pp. 439, 44O). — Experimental evidence cited 

 is claimed to show that not only anesthetics but a variety of other agencies pro- 

 duce the blackening of leaves studied in A. japonica. It is stated that the only 

 character common to these agencies is not that they are activators of enzyms 

 but that they tend to produce death of the tissues. The blackening is held to 

 • be a- result of changes of permeability whereby enzyms more readily pass into 

 the tissues, as claimed by Maquenne and Demoussy (E. S. R., 23, p. 131). 



Studies on photosynthesis, K. Puriewitsch (Jahrh. Wiss. Bot. [Pringsheirn], 



53 (1913), No. 2, pp. 210-254, figs. Jf8).— The utilization rate of the leaves 



. (so far as tested) for incident solar energy as related to photosynthesis was 



found to vary from 0.6 to 7.7 per cent. The average rate shown by. Acer plata- 



noides was 1.3 per cent and that by Polygonum sachalineiise 3.6 per cent. 



