282 PHYSIOLOGY [Bot. Absts., Vol. V 



stomata are closed and water loss is cuticular. Removal of hairs increases cuticular water 

 loss only. As water loss from surface of mesophyll cells is 20 to 40 times cuticular water loss, 

 leaf hairs maybe disregarded as protection against ordinary wind and light. — H. D. Hooker, Jr. 



MINERAL NUTRIENTS 



2149. Ames, J. W., and C. J. Schollenberger. Calcium and magnesium content of vir- 

 gin and cultivated soils. Soil Sci. 8: 323-335. 1919.— See Bot. Absts. 5, Entry 2293. 



2150. De Turk, Ernest. Potassium-bearing minerals as a source of potassium for plant 

 growth. Soil Sci. 8: 269-301. 1919.— See Bot. Absts. 5, Entry 2290. 



2151. Howard, L. P. The relation of certain acidic to basic constituents of the soil 

 affected by ammonium sulfate and nitrate of soda. Soil Sci. 8:313-321. 1919. — See Bot. Absts. 

 5, Entry 2261. 



2152. Lamprov, E. Les engrais radioactifs. [Radioactive fertilizers.] Rev. Hortic. 

 [Paris] 91: 393-394. 1919.— See Bot. Absts. 6, Entry 123. 



2153. Rudolfs, W. Influence of sodium chloride upon the physiological changes of living 

 trees. Soil Sci. 8: 397-425. 7 pi. 1919. — The application of 1 to 10 pounds of sodium chlo- 

 ride to oak, birch, and maple trees shows a favorable effect in the smaller amounts and a toxic 

 action in the larger. Maple is most easily affected, followed by birch and oaks. The higher 

 trees are more resistant than the lower ones of the same species. — W. J. Robbins. 



2154. Shive, John W. The influence of sand upon the concentration and reaction of a 

 nutrient solution for plants. Soil Sci. 9: 169-179. 1920. — A nutrient solution, consisting of 

 potassium dihydrogen phosphate, calcium nitrate, and magnesium sulphate was added to 

 washed or unwashed sea sand #nd after longer or shorter intervals of contact, the solution was 

 drawn off and the freezing point and hydrogen-ion concentration determined. With washed 

 sand no adsorptive effect was noted. The unwashed sand during the first 24 hour period 

 reduced the freezing point of the solution 8.5 per cent but did not affect the reaction. By 

 renewing the solution, the adsorptive effect of the washed sand was eliminated. — W. J. Robbins. 



2155. Winterstein, E. Uber das Vorkommen von Jod in Pflanzen. [The occurrence of 

 iodine in plants.] Zeitschr. Physiol. Chem., 104: 54-58. 1919. 



PHOTOSYNTHESIS 



2156. Anonymous. Starch formation in leaves, and photographic prints. Sci. Amer. 

 Monthly 1:416. 1920. 



METABOLISM (GENERAL) 



2157. Allen, Paul W. "Rope" producing organisms in the manufacture of bread. [Ab- 

 stract.] Absts. Bact. 3: 4. 1919. — Bacillus subtilis and 14 other very similar spore-bearing 

 organisms produced "rope" in bread during the first 30 hours when bread was stored at 25°. 

 Bacillus bulgaricus, B. aerogenes viscosus, and Bact. lactis viscosus failed to produce "rope" 

 under similar conditions. — In a commercial bread oven the internal temperature of a loaf 

 did not reach 100° although the oven was held uniformly at 204°. [From author's abstract 

 of paper read at scientific session, Soc. Amer. Bact.] — D. Roddick. 



2158. Allen, Paul W. The manufacture of starch and other corn products as affected 

 by "rope" producing organisms. [Abstract.] Absts. Bact. 3: 4. 1919. — "In a wet process 

 of the manufacture of products from corn, 'rope' production often develops during hot weather, 

 causing serious difficulties in the operation of the reels and cutting down the yield of starch 

 per bushel of corn. — B. bulgaricus was repeatedly isolated from viscous starch and gluten 



