218 EXPERIMENT STATION RECOBD. 



study may give transpiring power a value as a systematic character, also that 

 its reciprocal, resistance to water loss by transpiration, may prove to be of 

 practical value in agricultural work. 



Photochamical effects from the mercury vapor lamp contrasted with those 

 from simlight, A. J. KiurvEB (Osterr. Bot. Ztschr., 6S (WIS), No. 2, pp. 

 49-51). — The author, calling attention to work done by himself (B. S. R., 27, 

 p. 827) and others, maintains that it is inadmissible to assume that under 

 sunlight certain photochemical processes go on just as observed under the 

 light of the mercury vapor lamp, since practically all the shorter wave lengths 

 are absorbed from the former by the air. 



Light as a factor inducing plant succession, B. C. Gates {Rpt. Mich. Acad. 

 Sci.. 13 {1911), pp. 201, 202, fig. 1; al)s. in Bot. CentU., 122 (1913), No. S, 

 p. 71). — An account is given, with graphical quantitative representation, of the 

 retreat of blue grass from the shaded area under a basswood tree, its advance 

 toward the trunk on defoliation of the tree due to cold, and its retreat again 

 on refoliation in the summer, also of the behavior of chickweed and moss 

 during these changes. 



The mode of action of weak solutions of electrolytes on germination, 

 H. MicHEELS {Acad. Roy. Belg., Bid. CI. Sci., 1912, No. 11, pp. 753-765; abs. in 

 Internat. Inst. Agr. \Roine'\, Mo. Bui. Agr. Intel, and Plant Diseases, 4 {1913), 

 No. 2, p. 19S). — In order to test the hypothesis that differences in favorable or 

 deleterious effects observed between anodic and cathodic solutions are due to 

 differences set up in the acidity or alkalinity of the liquids, the author studied 

 the comparative effects observed on adding small quantities of acids and 

 bases, also those of electrolyzed solutions. The results are considered to con- 

 firm previous conclusions (E. S. E., 25, p. 25), showing further that the chief 

 differences are primarily due to the liberation of ions, particularly the cations. 

 It is also suggested that the retardation effects observed as to growth are 

 caused by a colloidal precipitation in the root cells. 



The limits of germination of seeds after being placed in salt solutions, 

 P. Lesage {Compt. Rend. Acad. Sci. [Paris], 156 {1913), No. 7, pp. 559-562, 

 fig. 1). — In continuation of investigations previously reported (E. S. R., 27, 

 p. 330), the author has studied the limits of germination of seed when placed 

 for different lengths of time in varying solutions of the nitrates, sulphates, and 

 chlorids of sodium, potassium, and ammonium. The results are shovsm in a 

 series of curves, the ordinates and abscissas of which represent the time and 

 strength of solutions. 



Effects of using salt solutions for watering and sprinkling plants, J. 

 KrrijPEB {Dept. LandJ). Suriname Bui. 2S, 1912, pp. 25-31). — In several series 

 of experiments employing salt solutions varying from 0.025 to 4 per cent on 

 coffee, cacao, and other plants, it was found that the injurious effects appeared 

 at a point ranging from about 0.5 to 1.5 per cent, the results being somewhat 

 complicated by rainfall. 



The displacement by water of nitrogenous and mineral materials con- 

 tained in leaves, G. Andee {Compt. Rend. Acad. Sci. [Paris], 155 {1912), No. 

 26, pp. 1528-1531; 156 {191S), No. 7, pp. 564-566).— In continuation of his in- 

 vestigations (E. S. R., 27, p. 525), the author gives the results of studies on the 

 hydrolysis and solution of nitrogenous and mineral constituents in chestnut 

 leaves when placed in water to which a little formaldehyde was added. 



The results obtained are considered analogous to those following the autumn 

 fall of leaves. It was found that the greater proportion of the nitrogenous 

 constituents, phosphoric acid and potash was rather quickly leached .from 

 the leaves. 



