No. 1, July, 1920] PHYSIOLOGY 241 



if any. (3) The sense of orientation is not specifically related to the concenl ral ion of chemi- 

 cals in the environment. Spondylomorum probably may be either negative or positive in any 

 solution in which it orients al all. Theeffed of acids on the en e of orientation is probably 

 due to the reduct ion of hydroxy! ions produced in t be cull ure solul ion by I be acids. (5) Re- 

 duction in the concentral ion of bydroxyl ions, increa e in anesthetics, increase in temperature, 

 and decrease in lighl , produce I lie same change in t he mi e of orient ;it ion, and thi 

 occur without any change in t he environment. It is, therefore, probably due to some specific 

 change in the physiological process in the organism, which may be induced by a number of 

 different factors. (6) Reversion depends upon the time-rate as well as upon the magnitude of 

 change in the concentration or intensity of the effective factor- in 'he environment. —S. 0. 

 \iaat. 



1601. SCHANZ, Fritz. Einfluss des Lichtes auf die Gestaltung der Vegetation. [The 

 influence of light on vegetation.] Ber. Deutsch. Bot. Ges. 36: 619 632. 1918. — Leontopodium 



alpinum, the Swiss Edelweiss, when grown at low altitudes loses its dwarf characteristics and 

 develops into a tall plant. Artificial elimination of the ultra-violet rays produces similar 

 effects not only on Edelweiss but also on plants like begonia, lobelia and potato. It appears 

 then that the ultra-violet light retards growth and inhibits elongation and that, broad I v 

 speaking, the rays of short wave length arc the determining factor in the height development 

 of the vegetation. — Ernst Artschwager. 



1602. Shull, C. A. Photometry. [Rev. of: Ridgway, Charles S. A promising chemi- 

 cal photometer for plant physiological research. Plant World 21:234-240. 1918 (See Bot. 

 Absts. 3, Entry 2910).] Bot. Gaz. 68:71. 1919. "If the instruments and methods of 

 using the solution can be reliably standardized, the inexpensiveness of the materials, ease of 

 taking readings, accuracy of determinations, and its automatic integration for variable condi- 

 tions of light will make it an excellent instrument for extending our knowledge of the influ- 

 ence of light as related to life processes." — Author's summary. 



1603. Sugitjra, K., and S. R. Benedict. The action of radium emanation on the vitaminss 

 of yeast. Jour. Biol. Chem. 39: 421^433. 1919. — Growth-promoting factors in yeast may be 

 inactivated partially by means of exposure to radium emanation. — G. B. Rigg. 



TOXIC AGENTS 



1604. Anonymous. Prejudicial effects of treatment with formalin upon the germination 

 of seeds. Sci. Amer. Supplem. 87: 164. 1919. 



1605. Clayton, E. E. Hydrogen cyanide fumigation. Bot. Gaz. 67:483-500. * fig. 

 1919. — Different concentrations of hydrocyanic acid gas gave effects ranging from stimulative 

 to depressive. The maximum of benefit was secured from concentrations deadly to insect life, 

 but just a little below the point of first injury to the plant. Wetting the leaves had a beneficial 

 effect on the tomato. Reduced temperature and low light intensity during the day preceding 

 fumigation increased resistance. Injury closely paralleled the stomatal movement, increasing 

 as the size of stomatal aperture increased. A higher or lower water supply in the soil affected 

 resistance, through hastening or retarding the growth rate. Rapidly growing plants were 

 susceptible to injury, while slow-growing plants were more resistant. High reducing sugar 

 content seemed to be correlated with maximum resistance. — E. E. Clayton. 



1606. Crocker, William. Organic plant poisons. [Rev. of: Brenchley, Winifred E. 

 Organic plant poisons. I. Hydrocyanic acid. II. Phenols. Ann. Botany 31: 447— 156. 1917. 

 Ibid. 32 : 259-278. 1918. (See Bot. Absts. 1, Entry 1659).] Bot. Gaz. 67: 1S2-1S3. 1919. 



1607. Crocker, William. Effect of illuminating gas on plants. [Rev. of: Wehmer, C. 

 Leuchtgaswirkung auf Pflanzen. 4. Die Wirkung des Gases auf das Wurzelsystem von Holz- 

 pflanzen; Ursache der Gaswirkung. Bor. Deutsch. Bot. Ges. 36: 140-144. 191S (See Bot. 



BOTANICAL ABSTRACTS, VOL. IV, NO. 1 



