DISEASES OF PLANTS. 845 



Examinations of anatomical and pljysiological data are not decisive as to 

 whether the mycelium passes from a dead branch to the main axis through the 

 vrood or just outside it. Death of dormant buds is considered as a possible 

 means of infection of the stems, but probably this is of no great imixtrtance. 

 It is held that the most important source of infection are the dead limbs left 

 on the stems, this suggesting removal of affected branches before they are 

 dead, preferably during dry mouths when spores of this fungus are not being 

 given off. 



A disease of pine shoots (Quort. Jour. Forcstrif, (1915), No. 1, pp. 6.'t, 65). — 

 A fungus, said to be more common on the Corsican pine than on Scotch pine 

 and some other conifers, has been identified as Cenatuiuim abietis. Infection 

 occurs in late autumn or winter. The leaves begin to fall rapidly in early sum- 

 mer, the shoots of the previous year's growth often being completely defoliated. 

 The bud of an infected shoot rarely expands at all. Both ascosiwres and one 

 to three celled conidia in large quantities are said to be produced by the fungus. 



A leaf cast of pines in Sweden, T. Lagb31bebg (Mcddel. Stat. Skoffsforsoksanst. 

 (Mitt. For.rtl. T"c/-s. Annt. SchwedetK^), No. 10 {1913), pp. 139-180, XVII-XXII, 

 figs. 8). — A leaf disease of pines is described in its several stages and as to its 

 effects on the foliage and trees. It is said to show jiycnidia corresiwnding to 

 those borne by Leptostronia pinastri, the conidial stage (Lophodermiuni 

 pinitstri) being already known. A bibliography is given. 



A disease of oaks in Westphalia, Hey {Ztschr. Forst ti. Jagdic, 46 (1914), 

 No. 10, pp. 595-598). — The author cites facts recently observed by himself which 

 are held to indicate that AnHiUaria mellea is the cause of the dying out of oak 

 trees and also of beech in one case noted. 



A timber rot accompanying' Kymenochfete rubig-inosa, H. P. Bkown (My- 

 cologia, 7 (1915), No. 1, pp. 1-20, pis. 3). — The author describes the results of inva- 

 sion by IT. luhiginosa and its saprophytic activity in case of decorticated chest- 

 nut (also, but more rarely, of oak) near Ithaca, N. Y.. and also the development 

 and habits of this fungus. 



The fi'uit bodies are annual and xerophytic, spores being shed intermittently 

 during moist periods for several months. A superficial p<>ripheral type of decay 

 usually accompanies the typical decay due to this fungus. 



Studies in dry rot, V, C. Wehmer (Mycol. Centbl., 4 {1914), Nos. 5, pp. 241- 

 252, fly. 1; 6, pp. 287-299, pis. 2).— In continuance of previous reports (E. S. R., 

 31, p. 248) the author gives detailed results of f;tndies on conditions as favorable 

 or unfavorable to development on structural woods, etc., by Merulius, including 

 the influence of previous sterilization, of impregnation with nutritive substances, 

 and of lowering the temperature during the tests. 



Air-dry or dampened, but not strictly sterile, fir wood was not severel.v 

 attacked by detached mycelium of Merulius, even in a moist chamber, the ex- 

 I>eriments indicating a high degree of sensitiveness of this fungus to conditions 

 as regards both nutritive materials and the presence of other organisms (bac- 

 teria, yeasts, and other fungi). Other experiments with strictly sterile moist 

 heartwood or sapwood gave a growth the luxuriance of which was in close 

 relation with the degree of moisture present in the materials attacked (moisture 

 of the air showing little if any influence). Spore development was not 

 obtained on either air-dry or dampened wood. Attached mycelium, however, 

 proved much less sensitive to conditions hindering growth in detached portions. 



The liability to extension by Merulius appeal's, therefore, to be in practice 

 somewhat limited by the tendencies above noted. 



