AGRICULTURAL BOTANY. 721 



placed in a dilute solution of alcohol will not germinate except as certain molds 

 are present which destroy the alcohol and thus assist in stimulating the devel- 

 opment of the embryo. 



The nature and uses of hard seeds, Bebtha Rees (Jour. Dept. Agr. Victoria, 

 8 (1910), No. 12, pp. 770-773, pi. i ) .—Attention is called to the fact that many 

 leguminous plants have seeds which on account of their slow germination are 

 designated as hard seeds, and that these plants have a tendency to produce a 

 higher percentage of hard seeds when grown in a dry climate than in a moist 

 one. The author discusses the various theories relating to the nongermina- 

 tion of these seeds and describes the experiments of Jean White (E. S. R., 20, 

 p. 629) in which it was found that seeds have an impermeable membrane con- 

 sisting of a cuticularized layer that prevents the entrance of water. 



The author has examined the seeds of a considerable number of leguminous 

 and other plants, and found that with the exception of canna there was a well- 

 defined cuticle outside the palisade cells. This cuticular layer is believed to be 

 formed by the laying down of waxy or fatty substance in the cell wall and to 

 consist of the original cell wall permeated through and through with particles 

 of wax. The action of abrasion, hot water, and chemicals upon this layer is 

 described. 



On the retention of mineral matter taken up by annual plants during 

 growth, G. Andre (Compt. Rend. Acad. Sci. [Paris], 151 (1910), No. 26, pp. 

 1378-1382).— The author has made a study of beans, white lupines, and pinks 

 from the beginning of their growth to maturity, and finds that they retain 

 practically all the mineral materials taken from the soil. 



The data for the pinks are given in detail. The plants were analyzed at 5 

 periods of growth, the nitrogen, phosphoric acid, lime, magnesia, and potash 

 being determined. There was found to be a constant increase in the fresh 

 weight of the plants up to the flowering period, after which there was a loss. 

 The dry matter and ash, however, continued to increase until after maturity, 

 when the leaves had become completely dry. An examination of the ash and 

 nitrogen showed a steady increase up to the period of fruiting, when the mag- 

 nesia became constant and there was a slight falling off in the proportion of 

 phosphoric acid. In the case of the phosphoric acid it is thought that the 

 plants did not take any of this substance from the soil after the setting of the 

 seed and that the loss represents the amount required for their development. 

 The increase in lime and potash is said to indicate that the plant continues to 

 take mineral materials from the soil throughout all stages of development. 



The increased tolerance of maize to boron, H. Agulhon (Compt. Rend. 

 Acad. Sci. [Paris], 151 (1910), No. 26, pp. 1382, 1383).— In a previous publi- 

 cation (E. S. R., 23, p. 230) the author has shown the optimum amount of 

 boron which plants will endure. Subsequent investigations carried on with 

 maize indicate that plants may accustom themselves to still greater quantities 

 of boron and that this increased resistance is transmitted. In his experiments 

 the progeny of the second generation of maize was able to withstand quantities 

 of boron that were toxic to check plants. 



Observations on tlie biology and pathology of sterility in the olive, L. 

 Petri (Atti R. Accad. Lined, Rend. CI. Sci. Fis., Mat e Nat., 5. ser., 19 (1910), 

 II, No. 12, pp. 668-671). — In a general discussion of the probable causes for 

 the shedding of immature olive fruits, the author suggests that the lack of an 

 adequate supply of water during the formation of the sexual organs of the 

 olive flowers is probably one of the principal causes of a large percentage of 

 aborted ovaries. 



94492°— No. 8—11 3 



