Water-Content of Plants 63 



bean, cabbage, cudweed, or other plants available. Some of 

 these should be leaves readily wetted, and others provided with 

 a bloom, or with hairs effectively preventing wetting. Permit 

 the leaves to wilt slightly, then weigh each kind accurately upon 

 a delicate balance. Next place the leaves in water in a dark 

 chamber, immersing all parts except the petioles (or, previous 

 to weighing, seal the petioles carefully with wax). After from 

 6 to 24 hours note any change in the rigidity in the leaves ; 

 also remove all moisture from the surface with filter paper, 

 weigh carefully, as before, and compare the weights of each 

 kind. 



REFERENCES 



DANDENO, J. B. Effects of Water and Aqueous Solutions of 



Some Inorganic Substances on Foliage Leaves. Trans. 



Canad. Inst. 7 : 238-350, 1901. 

 FREIDENFELT, T. Studien iiber die Wurzeln krautiger Pflanzen. 



Flora 91: 115-208, 1902. 

 HEDGECOCK, G. G. The Relation of the Water-content of the 



Soil to Certain Plants. Botan. Survey of Nebr. 6 : 79 pp., 



1902. 



HILGARD, E. W. Soils. Pp. 188-310, 1905. 

 LYON, T. L., and FIPPIN, E. O. Soils. Pp. 136-165. 

 ROTMISTROV, V. Root-systems of Cultivated Plants of One 



Year's Growth. 57 pp., 22 figs. (Issued by the Experi- 

 ment Station, Odessa, Russia.) 

 SNOW, L. M. The Development of Root-hairs. Bot. Gaz. 40 : 



12^8, pi. 1, 1905. 

 SPALDING, V. M. The Biological Relations of Certain Desert 



Shrubs. I. Bot. Gaz. 38 : 122-160, 7 figs., 1904 ; II. Ibid. 



41 : 262-282, 1906. 

 TEN EYCK, A. M. The Roots of Plants. Kansas Agl. Exp. Sta. 



Bui. 127 : 199-252, 26 pis., 1904. 



TEXTS. Goodale, Jost, Pfeffer, Sachs, Sorauer, Stevens, 



