132 EXPERIMENT STATION RECORD, [Vol. il 



reported which showed 55.95 per cent of tricalcium phosphate, 2.44 per cent of 

 magnesium carbonate, and 7.1 per cent of iron oxid and aluminum. Since the 

 phosphates are evidently not suited to the manufacture of superphosphate it 

 has been recommended that they be used in fine ground condition. They are 

 being tested in this form as fertilizer for rice. 



Analyses of inspection samples, of fertilizers, 1917, J. T. Willaed, O. O. 

 SwANSON, and R. C. Wiley (Kansas Sta. Insp. Circ. 7 {WIS), pp. 16). — This re- 

 ports the results of the actual and guarantied analyses of official samples of 

 commercial fertilizers and fertilizing materials collected during 1917. 



AGRICULTTJUAL BOTANY. 



Report of plant physiologist, E. M. R. Lamkey {Delaware Sta. Bui. 122 

 {1918), pp. 30, 31). — A summary is given of investigations carried on in chang- 

 ing permeability and its relation to availability and the reactions of euzyms to 

 solutions within the plant. Work on these projects has not progressed very 

 far, but preliminary investigation has shown the necessity of considering tem- 

 perature, shade, sunlight, and moisture content of the soil in conjunction with 

 the permeability of the tissues and the availability of plant food. It has been 

 found that peach tissues may be equally permeable to certain salts under one 

 system of management while under another system they will be unequally per- 

 meable. In the study of the reactions of enzyms, the author has designed and 

 used apparatus for the determination of peroxidase and oxidase activities luider 

 known and controlled conditions. By use of the methods devised by him, the 

 peroxidizing, oxidizing, diastatic, and inverting euzyms of variously fertilized 

 trees have been studied throughout a single season. 



Growth, in organisms, D. T. MacDougal {Science, n. ser., 49 {1919), No. 1278, 

 pp. 599-605). — In an address before the Pacific Division of the American Asso- 

 ciation for the Advancement of Science, the author discussed growth as based 

 on the conception that living matter is composed mainly of pentosans and albu- 

 mins or albumin derivatives with lipins as a minor component and that gi'owth 

 of living matter consists of hydration with accompanying swelling and of 

 accretion of solid matter, the two processes being actually independent. En- 

 largement of cells is considered almost entirely due to the swelling which 

 results from hydration in their earlier stages, and later the enlargement of the 

 syneretic cavities in the colloidal structure is followed by the distending or 

 stretching action of osmotic pressures in the vacuoles thus formed. 



Root growth, in desert plants and the oxygen supply of the soil, W. A. 

 Cannon {Carnegie Inst. Washi^igton Year Book, 17 {1918), pp. 81-83). — It is 

 said that roots of Prosopis continue growth for a longer time in a soil atmos- 

 phere poor in oxygen, with no carbon dioxid, than is the case with Opuntia. 

 The oxygen, as well as the carbon dioxid, response thus appears to be specific, 

 at least as far as these two plants are concerned, and is thought, therefore, to 

 be a matter of ecological importance. The relative indifference of the roots of 

 Prosopis to soil aeration permits either deep or shallow growth and enables the 

 species to range widely as regards soils, while the relative dependence of the 

 roots of O. versicolor on good soil aeration prevents their striking to any con- 

 siderable depth and also excludes the species from soils of fine texture. 



Root absorption from solutions at minimum concentrations, R. B. Haevey 

 and R. H. True {Amer. Jour. Bot., 5 {1918), No. 10, pp. 516-521, figs. 2).— Fol- 

 lowing up the studies of True and Bartlett (E. S. R., 34, p. 224) with investi- 

 gations of equilibrium points as regards gain or loss of electrolytes by plants, 

 the authors found that in case of squash, peanut, soy beau, and sweet corn 



