32 EXPERIMENT STATION EECOED. 



The substitution of lignification and tuber bearing, which was only occa- 

 sional in the grafts of tomatoes and potatoes, was a constant occurrence when 

 artichokes and other tuber-bearing species of Helianthus were grafted upon the 

 annual suntiower. 



Comparison between the beginning' of the development of perennial and 

 annual plants, G. Andre (Compt. Rend. Acad. Set. [Paris], IJ/S (J 909), No. 8, 

 PI). 515-517). — In cotninuation of a previous note (E. S. R.. 20, p. 1125), the 

 author gives comparisons of bean and horse-chestnut seedlings during their 

 early development. 



In both the annual and perennial i)lants the mineral and nitrogenous mate- 

 rials in the cotyledons were used up during the growtli of the plant in about 

 the same proportions. The horse-chestnut was 4^ months in producing a 

 seedling weighing as much as the seed from which it came, while the bean ac- 

 complished it in 18 days. In this period of growth there had been lost from 

 the cotyledons of the horse-chestnut 81.2 per cent of their original phosphoric 

 acid, 72.8 per cent of the potash, and 82.3 per cent of the nitrogen. The bean 

 cotyledons lost about equal amounts during the corresponding 18-day period of 

 growth. 



Electrical stimulation of plant growth, A. B. Plowman {Ahs. in Science, 

 n. so:, 29 (1909), No. Iff2, p. Jjl'O). — As a result of experiments and observations 

 extending over a period of more than 10 j-ears, the author is convinced that 

 electrical charges of positive sign are moi'e or less inhibitive of the vital 

 processes of plant protoplasm through which such charges are caused to pass, 

 while, within a rather wide range of conditions, negative electrical charges 

 stimulate such processes, sometimes to a remarkable degree. 



The physiology of electrocultures, G. Gassner (Mitt. Deut. Landw. Gesell., 

 24 (1909), No. 1, pp. 5-7). — A review is given of the investigations of Lem- 

 strom, the author, and others on the effect of electricity on plants. The con- 

 clusion is reached that tlie electrical stimulus causes increased transpiration on 

 the part of the plant, and it is believed probable that the assimilatory and 

 respiratory functions are e<pially stinuilatcd. 



The relation bet'ween plant respiration and alcoholic fermentation, S. 

 KosTYTSCHEFB^ { Bcr. Dcut. Bot. Gesell., 26a (1908), No. 8, pp. 565-573; abs. in 

 Jour. Chem. Soc. [London], 96 (1909), No. 555, II, p. 6'.'/). — The author gives an 

 account of investigations on the respiration of plants, dealing particularly with 

 the hypothesis that the production of alcohol is an intermediate stage in respi- 

 ration. The exi)eriments were made with peas, and seem to indicate that in 

 respiration the plant sugar decomposes in the same way as in alcoholic fermen- 

 tation, but that the reaction does not go so far as alcohol production. T'he 

 intermediate substances produced during respiration are oxidized. 



The chemical laature of root excretions, J. Stoklasa and A. Ernst (Jahrh. 

 Wiss. Bot. [Pringsheim], J,6 (1908). No. 1, pp. 55-102; abs. in Bot. Gaz., 1ft 

 (1909), No. 3, pp. 2)9, 250). — A study was made of the excretions of the roots 

 of a number of plants. 



The authors found that no acid, either organic or inorganic, except carbonic 

 acid, was excreted by roots, if they were fully sui)i)lied with oxygen so that 

 aerobic respiration was unrestrained. In limited oxygen supply, certain organic 

 acids were formed and excreted, but in no case was any inorganic acid or salt 

 excreted. The organic acids appearing under limited oxygen supply varied with 

 the plants used. Buckwheat and barley gave formic and acetic acids, oats and 

 maize formic acid, and beets oxalic acid. It is believed that these acids arise 

 from the Incompletely oxidized products of respiration and that in a full oxygen 

 supply these acids will be oxidized into carbon dioxid and water. 



