376 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Oak, California Tanbark. Part 1 by Willis Linn Jepson, 

 Part 2 by H. S. Betts, Appendix by 0. D. Mell {U.S.A. Dep. Agr., 

 Forest Service, Bull 75; Sept. 20, 1911).— The Tanbark Oak {Quercus 

 densiflora) occurs through the coast ranges from Oregon to California, 

 and produces one of the most valuable tanning agents known for the 

 production of heavy leather. The timber, too, is valuable, and it is 

 suggested that there is no reason why Tanbark Oak should not take its 

 place in the Pacific Coast hardwood market for many purposes for 

 which Eastern hardwoods are now imported. — A. D. W. 



Oats and Stinking* Smut of Wheat and their Prevention, 



The Loose Smut of. By A. C. Johnson (U.S.A. Exp. Stn., Purdue, 

 Circ. 22, 1910). — A general description of the two above diseases is 

 given, and the treatment of the grain before sowing is recommended 

 with 1 lb. formalin to 50 gallons of water, sprinkled on and shovelled 

 over thoroughly and left for two hours in a heap. 



For other loose smuts of wheat and barley the formalin, hot water, 

 copper sulphate, and Sar " treatments have proved ineffective, and 

 the following modified hot-water treatment is considered to be worth a 

 trial. 



Soak wheat and barley seeds in cold water for five hours, then dip 

 the wheat seed in hot water at a temperature of 54° C. or 129° F. 

 for ten minutes, and barley seed in water at 52^ C. or 125*^ F. for 

 fifteen minutes. 



Good careful directions for the carrying out of these different 

 treatments are given. — D. M. C. 



Oedema on Manihot. By F. A. Wolf and F. E. Lloyd (Phyto- 

 pathology, ii. pp. 131-134; Aug. 1912; 1 plate; 1 fig.).— Ceara rubber 

 in a greenhouse at Alabama showed " intumescences " or oedema. 

 An account of the lesions produced is given together with a review of 

 the hterature. — F. J. G. 



Oil-seeds, Chemistry of. By Sergius Ivanow (Beih. Bot. 

 Cent. Bd. 28, Abt. i. Heft 1, pp. 159-191; 9 figs.).— The author gives 

 tables showing the chemical composition of Eape, Hemp, Poppy, and 

 Linseed, and traces the changes in the percentages of glucose and 

 saccharose and of oil during the process of ripening. 



He finds during the process the following : — 



Glucose 1 Glycerine ] Glyceride 



(carbohydrate) [ Saturated fatty acids — unsaturated acids / (oil) 



The vegetative parts and capsule of flax were also analysed, and 

 the results are given. 



He finds that until flowering the flax accumulates carbohydrates in 

 the stem and afterwards in the flower, so that the assimilation organs 

 die soon after flowering, and ripening is accomplished. Eape-seed, 

 Hemp-seed, Sunflower-seed, and Poppy-seed were also analysed, aud 

 the chemical results are given in full. 



