632 EXPERIMENT STATION EECORD. 



The value of molasses as a fertilizer, W. E. Ceoss {Intermit. Sugar Jour., 

 13 (1911), No. l.'iS, PI). 191-196).— Annlyses showing the fertilizing value of 

 molasses are quoted from bulletins of the Hawaiian Sugar Planters' and Louisi- 

 ana stations (E. S. It., 18, p. 373; 19, p. 32), and reference is made to experi- 

 ments which the author is undertaking to determine the fertilizing effect of 

 molasses when applied to soil, especially its relation to the nitrogen content of 

 soils. 



Guano deposits of Assumption Island, Seychelles, R. Dupont {Bill. Imp. 

 Inst. [So. Kensington], {1911), No. 1, pp. S9-.'f.'/; ahs. in Jour. Soc. Chein. 

 Indus., 30 {1911), No. 12, p. 760).— The extent, nature, and utilization of de- 

 posits of phosphatic guano on this island are discussetl. It is estimated that 

 46,000 tons of a high-grade guano and 50,000 tons of low-grade guano are 

 available. 



AGRICULTURAL BOTANY. 



Seasonal variation in the food reserves of trees, J. F. Peeston and F. J. 

 Phillips {Forestry Quart., 9 {1911), No. 2, pp. 232-2^3). — The authors present 

 a paper in which their observations regarding the food reserves of trees are 

 described and results of previous investigators are compared. 



The work reported in the present paper and that of European investigators 

 indicates that in the stems of all trees in temperate climates there is a reduc- 

 tion in the amount of starch present in autumn, the reduction in some trees 

 being so great as to cause its complete disappeai'ance. In a few trees a consid- 

 erable increase of fat in the phloem and xylem in the late autumn or early 

 winter is reported, but there is insufficient evidence for the belief that starch 

 is transformed into fat. Both hard and soft wood trees were found to contain 

 considerable fat in winter, and the authors do not agree with European writers 

 who propose classifying hard woods as starch trees and soft woods and gym- 

 nosperms generally as fat trees. There is apparently no great increase in the 

 content of sugar in the stems and roots, except in the spring as the buds unfold. 

 In the root, transformations do not keep pace with those of the stem, and starch 

 remains throughout the year, the greatest reduction occurring in the spring. 



The transformations of carbohydrates are generally dependent on the season, 

 although immediate conditions of temperature have souue effect. As has been 

 pointed out by others, the authors found that the maximum for total carbo- 

 hydrate reserves of deciduous trees is at the fall of the leaf in autumn, whereas 

 for the persistent-leaved trees the maximum is at the opening of buds in the 

 spring. 



On the chemotropism of plant roots, T. Porodko {Jahrb. Wiss. Bot. IPrings- 

 heim], 49 {1911), No. 3, pp. 307-388) .—Attev a brief review of the work of 

 other investigators on this subject, the author describes the methods used and 

 gives the results obtained in a series of experiments on the chemotropism of 

 the roots of Lupinus albus and Helmnthus annuus when grown in the presence 

 of various salts in agar-agar as a diffusion medium. 



The lupine roots reacted by curving, which occurred only with definite con- 

 centrations of a given salt. The upper and lower parts of the roots themselves 

 remained straight. Only the intermediate zone showed the curved reaction, 

 which varie<l in intensity, in form, and in direction according to the salt and 

 concentration under consideration. The angle of divergence of the curvature 

 varied between and 90°, due to the action of two forces, namely, the stimuli 

 of the salts used and gravity. The first acted on the roots in a horizontal 

 direction, i. e., at right angles to the main axis of the root, while gravity, on 

 the contrary, acted in a vertical direction, i. e., in the direction of the main 

 axis of the roots. According to the relative intensity of both forces, the roots 



