No. 2, June, 1921] PHYSIOLOGY 217 



on light perception in plants is here given. The various types of phototropic phenomena 

 are described and explained, and the great delicacy of the powers of light perception exhibited 

 by plants is presented. — A. W. Evans. 



1503. Troendle, Arthur. Der Einfluss des Lichtes auf die PenneabilitSt der Plasma- 

 haut und die Methode der Penneabilitats-Koeffizienten. [The influence of light on the per- 

 meability of the plasma-membrane and the method of coefficients of permeability.] Viertel- 

 jahrsschr. Naturforsch. Ges. Zurich 63 : 187-213. 1918.— The results of an earlier contribution 

 (1910) on coefficients of permeability are confirmed. New experiments, in which the quan- 

 tity of salt taken up in a given time was determined, confirmed the earlier conclusions. The 

 relations between the coefficients of permeability (m) and the quantity of salt taken up per 

 minute are theoretically derived. — John H. Schaffner. 



TOXIC AGENTS 



1504. Verschaffelt, Ed. Eeen en ander over de Werking van gasvormige vergiften op 

 planten. [The action of gaseous poisons on plants.] Pharm. Weekbl. 57: 1163-1175, 1920. — 

 The gases may enter the plant by dilTusion through the cuticle, which generally covers those 

 organs which have only a limited life; or through the tissue air spaces or the lenticels of the 

 cork tissue, the latter behaving differently with different plants. Trees and shrubs shed 

 their leaves very rapidly when exposed to illuminating gas or the vapors of oil of cloves. 

 Strong quick-acting poisons such as chloroform, hydrochloric acid vapors, and ammonia 

 prevent a meristematic separation of the cells, and the leaves do not fall off until the plant 

 is dead. Some Coniferae with definite cell layers in the needles shed these needles when 

 exposed to chloroform or other poisons. The shedding is the more rapid the more poison 

 is absorbed by the cork. This absorbs in 7 days 334.7 per cent of chloroform, 56.6 per cent of 

 ether, 26.4 per cent of carbon tetrachloride, 176.7 per cent of 10 per cent alcoholic caustic 

 potash solution, and 327.8 per cent of trichloracetic acid (25 gms. in 10 mils of water). The 

 saponifiable substances in the cutin and suberin appear to play an important role in the 

 poisoning of plants by gases. Anthocyan dyes are converted into white isomerids, the color 

 being restored by hydrochloric acid vapors. In some plants enzymes may take an important 

 part in hastening the poisoning. In some cases of poisoning strong odors are developed, for 

 instance, by the action of chloroform on garlic and related plants, where from glucosides 

 present in these plants alkyl sulphides are split off, which can be identified by lead acetate 

 paper. — H. Engelhardt. 



MISCELLANEOUS 



1505. Anonymous. Presence of copper in food plants. Sci. Amer. Monthly 2 : 204. 1920. 



1506. Wilson, J. K. Device for growing large plants in sterile media. Phytopath. 10: 

 425-429. 1 fig. 1^20. — The seeds are sterilized with calcium hypochlorite and germinated 

 in a short glass cylinder partially imbedded vertically in sterile agar contained in a test tube. 

 After the seeds germinate the cylinder containing agar and seedling is lifted out of the tube 

 and set into the mouth of a large flask which contains sterilized nutrient solution. Maize, 

 peas, and oats have been grown to maturity by this method. — William B. Tisdale. 



1507. Zerban, F. W., and E. C. Freeland. The color of sugar cane products and de- 

 colorization in factory practice. Sugar 21: 354-359b. 1919.— This is a reprint of Louisiana 

 Agric. Exp. Sta. Bull. 165. 32 p. 1919 (see Bot. Absts. 3, Entry 815).— C. W. Edgerton. 



1508. Zerban, F. W., t E. C. Freeland. El color de los products de la cana de azucar 

 y su decoloracion en la practica azucarera. [The color of sugar cane products and decolorization 

 in factory practice.] Sugar 21:444-447, 494-499. 1919.— This is a translation of Louisiana 

 Agric. Exp. Sta. Bull. 165 (see preceding Entry).— C. 17. Edgerton. 



