52 EXPERIMENT STATION EECOED. 



vei- and copper salts into the pyrogallic acid solution. A dark brown precipi- 

 tate of silver is found which is extremely adherent to the surface of the leaves. 



The Fusarium disease of asters, A. Osteuwalder (Lanclw. Jahrb. Schweis, 

 2Jt (1910), No. Jf, trp. 2^7, 248). — A description is given of a disease of asters 

 which causes the stems during the blossoming period to wither and dry up. 

 Near the ground the stems are dark colored. The disease seems to be due to 

 a Fusarium, probably F. incarnatum. 



Experiments on tree diseases, E. jMiJNCH (Naturtv. Ztschr. Forst u. Landw., 

 8 {1910), Nos. 8, pp. 389-J,08, pis. 3; 9, pp. 425-.'/.'/ 6). —This is a more extended 

 discussion of tree diseases, especially of those caused by wood-destroying fungi, 

 than the author's earlier paper (E. S. R., 22, p. 152) on the same subject, being 

 supplemented by data drawn from recent experiments in artificial infection of 

 living trees. The author reports and discusses the results of infection experi- 

 ments with SchisophyllKm commune, Stereum purpurcum, 8. hirsutum, S. 

 rvgosum, Polyporus igniarius, P. fomentarius, and CoUyhia vclutipcH, mainly on 

 100 to 120 year old beeches, but also on the horse chestnut and poplar. 



On the rotting of wood in dwellings by Coniophora cerebella, E. Schaffnit 

 {JaJircsher. Vcr. Angew. Bot., 7 {1909), pp. 246-253) .— After a careful examina- 

 tion of the rotting of wood in two dwellings, the conclusion is drawn that the 

 rotting due to C. cereheJla can not be controlled by attempting to prevent in- 

 fection, as the spores are continually flying in the air and may therefore infect 

 the wood both before and after it is used in the building. 



The subsequent rotting of the wood is due to its high water content, which 

 results either from a lack of proper drying before use, or to subsequent wetting 

 during storage or the process of building. To prevent the danger of rotting, 

 the timber must be thoroughly dried before using, a subsequent wetting during 

 building must be avoided, and smooth wood surfaces should be painted with 

 some disinfecting material, such as tar, carbolineum, etc. 



Oxidizing enzyms and their relation to sap stain in lumber, I. W. Bailey 

 (Bot. Gas., 50 {1910), No. 2, pp. 1 ',2-1 47). —The discoloration of sapwood, or 

 sap stain, is said to involve the loss or the depreciation in value of large quan- 

 tities of lumber annually. The phenomenon is illustrated by the reddish-yellow 

 or rusty coloi-ed sap stains occurring in the sapwood of alder, birch, and cherry, 

 and by the blue colored sap stains in the red gum. 



The author has made a study of the causes of this stain, and finds that in 

 genei-al it is produced in two wa;y'S, by the attacks of fungi and by chemical 

 discoloration due to the activity of oxidizing enzyms. Hot, humid weather 

 is said to be very favorable to the activity of the ferments, while cold winter 

 weather is unfavorable. The oxidizing enzyms which produce the sap stain are 

 destroyed and their oxidizing action prevented by a temperature of 100° C. 



The author believes that treating the sapwood of alder, birch, and cherry, or 

 other species, with boiling water will destroy the oxidizing enzyms in the wood 

 and prevent the stain. In mill practice, this should be done by treating the 

 lumber in tanks of boiling water, and the author believes that this would be 

 a practical method of preventing the discoloration. 



Experiments on the influence of root fungi on the thriftiness of chestnuts, 

 H. MtJLLER and O. Schneider {Landw. Jalirh. Schvjcis, 24 {1910), No. 4, PP- 

 234, 235). — ^As a result of experiments on chestnut seedlings it is claimed that 

 the presence of root fungi (Mycorrhiza), at least during the first years' growth 

 of the seedlings, is of no great value. 



A fungus disease on the leaves of TJlmus campestris, G. Dorogin {Ztschr. 

 Pflmisenlcrank., 20 {1910), No. 5, pp. 261-263, figs. 2).— A leaf spot disease of 

 the elm duo to Glceosporiuin inconspicuiitn campestris n. var. is described. 



