430 EXPERIMENT STATION RECORD. * 



to be characteristic of succulent plants. The acidity of plants was found to 

 increase in the absence of oxygen and to decrease with an increased supply 

 in the atmosphere. The experiments showed conclusively that the diminishing 

 acidity from early morning to late in the afternoon is a combined temperature 

 and light reaction. 



Influence of light and of shade on shoots of woody plants, H. Faeenholtz 

 (Bot. CentU., Beihefte, SI (1913), 1. AM., No. 1, pp. 90-118).— Giving results of 

 a study of light as influencing development of branches and seedlings of beech, 

 elm, and other forest trees, the author states that the anatomical structure of 

 the branches is altered in several respects under the influence of different illumi- 

 nations. A number of differences of anatomical resix)nse are noted between the 

 effect on long and that on short branches in this respect, while comparatively 

 small differences appear in twigs of the seedlings. The latter are said to show, 

 when grown in light, similarities to shade grown branches of older plants of the 

 same kind. Beech buds grown in sunshine are said to show peculiarities as 

 regards number, size, and internal structure, as compared with those produced 

 in shade. 



A bibliography is appended. 



Influence of shading on composition of tobacco, A. Stutzeb and S. Got 

 (Biochem. Ztschr., 56 (1913), No. 3, pp. 220-225).— Experiments described with 

 tobacco grown under controlled conditions are claimed to show that a large 

 percentage of nicotin can be produced by abundant sunlight, high temperature, 

 liberal nitrogen manuring, and sparing use of water in the soil; also that 

 direct sunlight favors a high potassium, but a low chlorin, content. 



Sensitive life of Asparag'us plumosus. — A morpho-physiological study, 

 F. C. Newcombe (Bot. CentU., Beihefte, 31 {1913), 1. AU., No. 1, pp. 13-42).^ 

 The author concludes a somewhat detailed summary of results obtained from 

 a study of the various tropisms of A. plumosus nanus by stating that the bio- 

 logical significance of various characteristics of this plant when grown in 

 darkness, such as the removal of inhibition of elongation of the aerial shoot, 

 the cessation of twining, the failure to unfold lateral buds, and the absence or 

 stunted growth of needles, may be referred to the conservation of building 

 material. It is thought that the significance of the bending to a horizontal 

 position of the upper portion of the aerial shoot from the rhizome and of the 

 seedling may be that it brings the assimilating part of the plant into a more 

 favorable position with respect to light. 



An esamination into experiments on the action of atmospheric electricity 

 on plants, P. Lesage (Compt. Rend. Acad. Set. [Paris], 157 {1913), No. 18, 

 pp. 784-787, fig. 1). — The investigations of Grandeau, who found that plants 

 grown under wire cages and submitted to the influence of atmospheric elec- 

 tricity were retarded in growth, are reviewed. The author grew cress and 

 Datura under wire cages, under a cage of silk thread of the same diameter 

 and mesh as the galvanized iron wire used, and in the open. 



The experiments with cress did not give any striking results, although the 

 plants grown under both cages were somewhat different from those cultivated 

 in the open. In the case of the Datura, the plants of which were grown from 

 July to September, those under both cages were decidedly reduced in size, the 

 ones under the wire cage, however, being slightly better developed than those 

 under the silk cage. 



During the progress of these investigations the author examined other phe- 

 nomena connected with the differences under the cages, and reports that evapo- 

 ration was greatly reduced under the protection of the cages. 



