128 EXPEEIMENT STATION EECORD. 



Evaporation and soil moisture in relation to the succession of plant asso- 

 ciations, G. D. Fuller {Hot. Guz., 58 {VJL'i), No. 3, pp. J9.i-23^. flys. 27).— The 

 author gives data collected during several years as to various plant associations 

 near Chicago, 111., stating among other conclusions that the ratios between 

 evaporation and growth water in the beech-maple forest, oak-hickory forest, oak 

 dune, pine dune, and cottonwood dune associations have the comparative values 

 of 100, G5, 20, 17, and 15, respectively, and that these differences may be the 

 cause of succession. The midsummer conditions of the prairie association seem 

 to be decidedly xerophytic. 



A bibliography is given. 



Branch development in a perennial plant, G. Andr^ (Compt. Rend. Acad. 

 Sci. [Paris}, 158 (1914), No. 21, pp. i5J7-J520).— Reporting on his more recent 

 work (E. S. R., 29, p. 218), and giving the results of analytical studies made at 

 five dates in the development of chestnut shoots as to the leaf and twig content 

 in dry matter, ash, nitrogen, phosphoric and sulphuric acids, and calcium, mag- 

 nesium, and potassium oxids, with the seasonal variations observed, the 

 author states that the annual shoot is found to increase considerably in absolute 

 nitrogen and in fixed materials, and that the leaf increases continually in con- 

 tent of assimilated materials, excepting phosphoric acid, until the latter part 

 of the growing period. October 8, about two weeks before the leaves begin to 

 fall, they were found to contain the greater part of the material appropriated. 

 The annual branch as a whole retains in the main the substances that have been 

 accumulated, the leaves giving up very little of any component except nitrogen 

 and phosphoric acid until just before their separation from the branch. 



Rapidity of hydrolysis and of removal by water of the nitrogenous and 

 mineral matter in leaves, G. Andee {Compt. Rend. Acad. Sci. [Paris'], 158 

 il91Jf), No. 24, pp. 1812-1815). — Reporting exact analyses at several periods 

 during the growth of chestnut leaves, the author states that the general con- 

 clusions presented above are sustained in the work here noted. The exosmosis 

 of minerals from the leaves is given as regards nitrogen, phosphorus, and potas- 

 sium, and is stated to have increased for these comiionents in the order named. 



The relative chemotropic influence of salts of metals on radicles of Lupinus 

 albus, T. M. PoRODKO (Bcr. Dcut. Bot. Gcscll, 32 {19U), No. 4, pp. 211-215).— 

 Continuing previous work on L. albus (E. S. R., 31, p. 325), but employing 

 herein salts of metals, the author details in tabular form the results obtained, 

 stating that all the salts tested gave negative tropisms. 



Conditions of chemotropism in rootlets, T. M. Porodko (Ber. Dent. Bot. 

 Gescll., 32 (1914), No. 4, pp. 215-282, figs. 2). — Continuing the above work, and 

 giving details and curves obtained therefrom, the author states that both positive 

 and negative tropism occur only with limited sti-engths of certain substances 

 named, and that chemotropic sensitivity is limited to about 1 to 2 mm. of the 

 root tip. 



Zinc in glass containers as a source of error in studying the biological 

 influence of chemicals, M. Javillier {Compt. Rend. Acad. Sci. [Paris], 158 

 {1914), No. 2, pp. 140-143; abs. in Jour. Chem. 80c. [London], 106 {1914), No. 

 617, I, pp. 364, 365). — Experiments cited, employing Stcrigmatoeystis nigra, 

 showed a gain in dry weight on the addition of zinc to cultures in flasks of 

 quartz and of Bohemian glass, but not to cultures in Jena glass, the differences 

 being attributed to zinc present in Jena glass. This influence of traces of zinc 

 in such glass may, it is thought, prevent accuracy of results in delicate tests. 



The mobility of potassium in vegetable tissue, L. Maquenne and E. De- 

 MoussY {Compt. Rend. Acad. Sci. [Parisi], 158 {1914), No. 20, pp. I4OO-I404).— 

 Analyses of portions of several kinds of plants subjected to an electrolyzing 



