BOTANICAL BOOKS 



AND SEPARATES OF JOURNAL ARTICLES 



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



profusely illustrated in color - - - - - - - --$3. 00 



Living Plants and their 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 



Atmometry and the Porous Cup Atmometer, by B. E. Livingston. Paper, 



64 pp., illustrated - - - - - - - - - - .75 



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 Colorado 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 serious 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 







Automatic Transpiration Apparatus 



The apparatus devised by Dr. E. X. Transeau for the graphic recording of 

 transpiration rate has been placed in our hands for sale. This apparatus was 

 described and illustrated in Botanical Gazette. Vol. 52, pp. 54-60. 



Full particulars and prices on application. 



THE PLANT WORLD, TUCSON, ARIZONA 



