BOTANY. ^ 447 



leaves of iris, begonia, and tobacco were found to agree essentially in the illuminated 

 portion forming the negative pole, the current reversing itself after the illumination 

 had ceased. The leaves of the garden tropseolum and Mathiola were the reverse of 

 the preceding, the illuminated portion being the positive jjole. 



The experiments seem to show that the difference in electric potentiality in plants, 

 when acted upon by light, is due to the chemical activity of the leaf, being particu- 

 larly associated with the phenomena of chlorophyll assimilation. The electric phe- 

 nomena were observed in living plants only. When the green leaves had been 

 subjected to boiling water or destroyed by dry heat there was no electric response. 

 Temperature was found to favor the production of electrical phenomena, and about 

 25°C., the same temperature as the optimum for assimilation, proved to be the 

 optimum for electrical response. 



In a second series of experiments the effect of chemical reagents on the electrical 

 response was investigated. Oxalic acid, hydroquinone, and laccase are being tested. 

 The general conclusion is drawn that whatever the organism examine<l the electric 

 response is intimately connected with the chemical reaction of the organism. 



A transpiration model, H. H. Dixon (*S'c(. Proc. Roy. Dublin Soc, n. ser., 10 

 {1903), I, Xo. 0, pp. 114-lJl, fiy. 1). — A description is given of a form of apparatus 

 in which the phenomena of turgidity of leaves of tall trees during the active transpi- 

 ration and transpiration into saturated atmospheres may be observed. From the 

 phenomena shown by the action of this model it is concluded that with imperfectly 

 semipermeable membranes, such as leaf cells are supposed to possess, transpiration 

 into saturated spaces is possible over long periods of time, and if photosynthesis is 

 permitted such transpiration may l)e intletinitely prolonged. 



The decomposition and regeneration of albuminous materials in plants, 

 G. Balicka-Iwanowska {Compt. Rmd. Acad. Sci. Cracovie, 1908; abs. in Bot. (Jentbl., 

 93 (1903), No. 41, p2). 369-373). — The author gives an extended review of the inves- 

 tigations of Pfeffer, Schulze, Prianishnikov, and others on the decomposition of 

 albuminous materials in plants, followed l)y an account of experiments conducted by 

 himself to test the accuracy of their conclusions. The methods of analysis adopted 

 were those usually employed in such studies, and the author found that asparagin, 

 which is formed during the decomposition of albuminous material, is a secondary 

 product, the primary produi-ts of decomposition being amrdo acids and hexose bases. 



The regeneration of albuminous material was found to be influenced to a very 

 appreciable degree by the salts present in the soils. In the absence of lime there 

 was found a decided diminution in the amount of albuminous material formed. 

 Assimilation on the part of the plant was found to play a very important role in the 

 formation of albuminoids, and his investigations confirmed those of Godlewski, who 

 found that under the influence of liglit the increase in albuminoids depends to a large 

 extent on the nitrates present without reference to the assimilative processes of the 

 plant. 



The localization of the active principles of certain plants during their 

 winter stages, W. Kussell {Rcr. (Ifn. Bol., 15 {1908), No. 17,.', jip. l'!0-16r>). — A 

 study was made of quite a number of species of trees, shrubs, and t)ther jjlants during 

 their dormant period, to determine the localization of alkaloids and other active 

 principles which are characteristic of the plants. As a result of the investigations it 

 seems that the alkaloids, glucosids, and other active principles are stored by the 

 plant similarly to the ordinary reserve material, and that in certain plants there 

 may be a slight transfer of the material during the dormant period. With those 

 plants whose aerial portions are amnial the active principles are localized in the sub- 

 terranean organs. With those having perennial stems the concentration of the 

 active principles is in the region of the buds, although frequently deposited to con- 

 siderable extent in the underground organs. 



