DISEASES OF PLANTS. 753 



readily infected tlian are brandies of a partly decayed trunk. In examining 

 the diseased material tyloses were found abundant in the outer wood, and there 

 is apparently a constant relation between the presence of the decayed area in 

 the trunk aad their formation. In addition to the above species, the author 

 frequently found fruiting bodies of Trametes sepium on catalpa stumps. 



Diseases of the chestnut and other trees, H. Metcalf (Trans. Mass. Ilort. 

 ^oc, 1912, pt. 1, pp. 69-95). — This is an address presented before the Massa- 

 chusetts Horticultural Society in which an outline account is given of various 

 forest tree diseases, particular attention being paid to the chestnut bark disease 

 (Diaporthe parasitica). The relation of the disease to the condition of the 

 tree is discussed, and outlines are given of methods for control, together with 

 the proposed program for combating the disease and preventing its spread. 



A bibliography is appended. 



Oak Oidium in France, G. Trinchiebi (Bui. 8oc. Bot. Ital., 1912, No. 4, pp. 

 100-102; Jour. Agr. Prat., n. ser., 23 {1912), No. 13, pp. Ji02, //03).— This is a 

 brief discussion of the contribution on this subject made by Arnaud and Foex 

 (E. S. R., 26, p. 551). The present author holds that a more complete com- 

 parison and experimental data ai"e necessary before the oak Oidium of Europe 

 can be safely considered as identified with the American species, Microsplicera 

 quercina. 



Uredo manihotis injuriou.s to Manihot glaziovii in Brazil, E. Ule ( Tropen- 

 pflanzer, 16 (1912), No. 2, pp. 91-95; abs. in Internat. Inst. Agr. [Rome'\, Bui. 

 Bur. Agr. Intel, and Plant Diseases, 3 (1912), No. 4, p. 1065). — The author re- 

 ports that this fungus was found by him to attack rubber trees in the State of 

 Ceara and neighboring regions, causing rust-colored spots on the leaves and 

 large excrescences and witches' brooms on twigs and branches, reducing the 

 yield of rubber, killing the branches, and eventually destroying the trees 

 affected. 



Careful pruning out and burning all diseased parts is said to be the only 

 remedy yet found effective. 



Prevention of mold, G. G. Hedgcock (Chicago [1912], folio). — This paper, 

 which was read before the National Slack Cooperage Manufacturers' Associa- 

 tion, St. Louis, Mo., May, 1911, gives a brief report on 10 experiments running 

 from 1905 to 1910. 



It was found that for the treatment of lumber sodium bicarbonate at a 

 strength of 5 to 8 per cent is, on the whole, the most economical and satisfactory. 

 Some other compounds, notably ix)tash alum and corrosive sublimate, either 

 have not been fully proved or are too dangerous to be unqualifiedly recom- 

 mended. Kiln drying is stated to be the best preventive of stain due to mold. 



The spreading qualities of spraying- mixtures, J. Weinmann (Prog. Agr. 

 et Vit. (Ed. VEst-Centre), 33 (1912), No. 23, pp. 709-712).— This is an account 

 of a series of experiments on the wetting capacity of Bordeaux and Burgundy 

 mixtures with addition of various substances to lower the surface tension and 

 permit greater spreading on the surface treated therewith. 



It was found that for the purpose in view ordinary white soap was as elfective 

 as a specially prepared soap sold in the form of powder. Polysulphids without 

 soap do not augment the wetting capacity of the mixture, but the two together 

 added to neutral or alkaline Burgundy mixure give excellent results. Sapindus 

 alone was found to give results almost equal to soap alone but inferior to a 

 mixture of the two. 



