No. 1, August, 1920] PHYSIOLOGY 1 [9 



supplied to the sand cultures in such quantities as to produce the differ adardsof mi 



ture. Culture solutions were renewed every third day. Daily water loss was restored 

 daily. Wheat was grown for 28 days.— The physiological balance of the uutrienl Bolutiom 



producing the best yields of tops and roots was oo1 altered by variations in the mo con- 



tent of the sand. A slight shifting of the balance, as affecting growth, is indicate, I for the 

 growth of 9 high-yielding cultures, as a whole, out of the series of 36, with each increase D 

 the moisture content of the cultures, from a position in the series characterized by lower par- 

 tial concentration of potassium phosphate to one of higher partial concentration of this salt, 

 and correspondingly lower ones of calcium nitrate and magnesium sulfate.— Good physio- 

 logical balance and optimum total concentration of a nutrient solution for plants i- qoI done 

 sufficient to produce the best growth of which the solution is capable when it is diffused as a 

 film on the particles of a solid substratum. An optimum degree of moisture is essential to 

 impart to the soil (sand) solution its maximum physiological value. The plant -producing 

 value of any fertilizer treatment is thus determined largely by the moisture conditions of the 

 substratum. — The lowest percentage of moisture employed corresponds with low yields of 

 tops and roots, lowest transpiration rates, and with lowest water requirement ratios. The 

 highest moisture content is associated with low yield of tops and roots, with high t ranspiral ion 

 rates, and with the highest water requirement ratios. The medium degree of moisture is 

 correlated with the highest yields of tops and of roots, high transpiration rates, and medium 

 water requirement ratios. — D. Reddick. 



S63. Steinkoenig, L. A. Relation of fluorine in soils, plants and animals. Jour. Indust. 

 Eng. Chem. 11: 463-465. 1919. — After reviewing the literature the author reports fluorine 

 determinations of 9 soils, using Merwin's determination with modifications, which is given 

 in detail. Fluorine occurs in amounts averaging 0.03 per cent. Three soils contained but 

 0.01 per cent, and in one case it was not found. Soils carrying stones made up of mica schist 

 contain relatively higher amounts, — Hagerstown loam 0.11-0.15 per cent, York silt loam 0.05 

 per cent. Fluorine is in the soil in such minerals as biotite, tourmaline, muscovite, apatite, 

 fluorite and phlogopite. Plants absorb fluorine and thus it is available for animals, which 

 latter may also obtain it from spring water. [See also Bot. Absts. 4, Entry 1636.] — C. R. Hursh. 



864. Stiles, Walter, and Franklin Kidd. The influence of external concentration 

 on the position of the equilibrium attained in the intake of salts by plant cells. Proc. Roy. Soc. 

 London 90 B: 448-470. Tables 1-13, 6 fig. 1919.— Salt intake by discs of carrot and potato 

 tissue was measured by changes in electrical conductivity of the external solution. The initial 

 concentrations used varied from N/10 to N/5000. Carrot is considered more suitable than 

 potato because of less exosmosis into distilled water. Toxic salts, e. g., copper sulfate, pro- 

 duce greater exosmosis in both distilled water and in solutions. — The ratio between final 

 internal and final external concentration is called the absorption ratio. The initial rate of 

 absorption is roughly proportional to the concentration of the external solution; but the final 

 absorption ratio, at equilibrium, diminishes as concentration of the external solution increases. 

 The equation of the absorption ratio is given as p KC m , where y is the final interval and C 

 the final external concentration. This happens to be the adsorption equation, but no basis 

 was found for postulating the mechanism of salt intake. — Paul B. Sears. 



PHOTOSYNTHESIS 



865. Pulling, H. E. Physiological problems of photosynthesis. [Rev. of: Henrioi, 

 Marguerite. Chlorophyllgehalt und Kohlensaure-Assimilation bei Alpen- und Ebenen- 

 pflanzen. Verhandl. Naturforsch. Ges. Basel 30: 43-136. 1918.] Plant ^Yorld 22: 123-126. 

 1919. 



METABOLISM (GENERAL) 



866. Armstrong, E. Frankland. The simple carbohydrates and the glucosides. 3rd 

 ed. IX+239p. Monographs on Biochemistry. Longmans, Green & Co.: London, 1919. — 

 No new chapters have been added since the second edition of this work, but much new material 



