BOTANICAL BOOKS 



AND SEPARATES OF JOURNAL ARTICLES 



Rocky Mountain Flowers, by F. E. and E. S. Clements. Cloth, 400 pp., 



profusely illustrated in co!or - - - - - - - - - $3.00 



Living Plants and thiir Properties, by J. C. Arthur and D. T. MacDougal. 



Cloth, 234 pp., illustrated - - - - - -■ - - 1.25 



Bibliography of Evaporation, by Grace J. Livingston. Paper, 121 pp. - 1.25 



Studies in Soil Physics, by E. E. Free. Paper, 42 pp. - - - . 75 



The Deserts of Egypt, by D. T. MacDougal. Paper, 27 pp., illustrated - .40 



The Desert Basins of the Colo-ado River, by D. T. MacDougal. Paper 25 



pp., illustrated, map - - - - - - - - - -.30 



An Improved Non-Absorbing Porous Cup Atmometer, by J. W. Shive. Paper, 



4 pp. - - - - - - - - - - - - - .20 



Hybridization of Wild Plants, by D. T. MacDougal. Paper, 16 pp. - - .30 



THE PLANT WORLD TUCSON, ARIZONA 



Pans for Retaining Power of Soils 



The results of different workers can be made comparable by the use 

 of uniform pans and a uniform method for the determination of the 

 maximum water-retaining power of soils. The pans here shown are 

 of heavy copper sheet, with perforated bottom and with wall 1 cm. 

 high. They are 11.5 cm. in diameter and hold approximately 100 

 cc. of soil, an amount small enough for easy handling and large 

 enough to avoid seiious errors in weighing. A circle of thin filter 

 paper should be placed in the bottom. See Hilgard's "Soils," p. 209. 



Each $1.25; Per Ten $10.00 



The Plant World .'. ,\ Tucson, Arizona 



A YOSEMITE FLORA 



BY 



HARVEY MONROE HALL and CARLOTTA CASE HALL 



A descriptive account of the Ferns and Flowering plants, including the Trees, of the Yosemite 

 National Park, with easy keys for their identification; covering most of the species of the 

 Sierra Nevada Mountains. 282 pages. Illustrated with 11 plates and 170 figures in the text. 

 Pocket size. Attractively bound in semi-flexible leather. Postpaid, $2.00. 



PAUL ELDER & COMPANY, Publishers 



239 GRANT AVENUE - - - SAN FRANCISCO 



