DISEASES OF PLANTS. 247 



ature appears to influence susceptibility of leaves to attack through its efl'ect 

 on turgidity. Both pure water and very concentrated nutritive media are un- 

 favorable to attack on the leaves, as also is complete etiolation thereof, partial 

 etiolation showing diverse results in this respect. Mineral nutritive materials 

 do not appear to influence attack directly. 



The yellow spot disease of cork oak, A Maige {Bui. Sta. Forest. Nord 

 Afrique, 1 {1912), No. 1, pp. 10-27). — ^A description is given of a disease of the 

 cork oak which is characterized by the occurrence of yellow spots on the bark. 

 The trouble seems to be due to the presence of micro-organisms, which are un- 

 able to attack the sound bark but develop following the presence of other 

 fungi, particularly some of the molds such as Aspergillus. 



Various methods are suggested for the control of this trouble, which is said 

 to be rather serious in some portions of nothern Africa. 



An enemy of the western red cedar, W. A. Mubbill {Mycologia, 6 {1914), 

 No. 2, pp. 93, 94, fig. 1). — Giving a description of a fungus recently noted, 

 claimed to be new and named Fonvitiporia weirii, the author states that the 

 species is abundant throughout northern Idaho and Washington, being the prin- 

 cipal fungus found in connection with decay of red cedar. It is said to continue 

 its destructive ravages in the heartwood and sapwood after the tree has fallen, 

 and it may even attack the bark. Separation of the annual layers in initial 

 stages is followed by a characteristic and easily recognizable brown friable rot. 

 Special investigation of this disease is contemplated for the field season of 1914. 



Cone bearing and cauliflory in witches' broom, P. Jaccabd ( Naturw. Ztschr. 

 For St u. Landw., 12 {1914), No. 3, pp. 122-128, fig. i).— The author describes a 

 very large witches' broom on a larch tree showiug male flowers on the stems, 

 and numerous cones, apparently normal, along with other peculiarities of an 

 anatomical or chemical nature. The witches' broom noted showed a healthy 

 green, contrasting strongly witli surrounding foliage which was discolored, fol- 

 lowing a general attack by Tortrix {Steganoptycha) pinicolana. 



A preliminary note on a new bark disease of the white pine, A. H. Graves 

 {Mycologia, 6 {1914), ^^o. 2, pp. 84-87, pi. 1). — Attention is called to a disease 

 spreading in circular areas in white pine groves in several localities in New 

 England. 



The bark shows a degree of contraction at or near the surface of the 

 ground, or in bad cases a girdling due to death of the bark. Of several 

 organisms isolated from the diseased areas since the discovery of the trouble 

 in 1911, a very common one, believed to be a Fusarium, is thought to be an im- 

 portant factor. Up to this time inoculations have apparently been unsuccessful, 

 but investigations are in progress and further results are to be published. Pend- 

 ing further study, the removal and destruction of all affected trees or parts 

 are insisted upon. 



White pine blister, W. C. O'Kane {Country Gent., 79 {1914), No. 6, p. 251, 

 figs. 3). — This is a popular account of this disease as far as known in the 

 United States. 



Fairy rings, E. Munch {Naturw. Ztschr. Forst u. Landic, 12 {1914), No. 3, 

 pp. 133-137, figs. 2). — The author discusses a fairy ring fungus, supposed to be 

 Agaricus maximus, and kept under observation for three years, stating that 

 attempts to extend the organism by transferring sward containing the mycelium 

 have not succeeded in spreading it beyond the original limits of the portions of 

 turf that were transferred. 



Two new wood-destroying fungi, J. R. Weie {U. S. Dcpt. Agr., Jour. Ayr. 

 Research, 2 {1914), No. 2, pp. 163-167, pis. 2).— Technical descriptions and 

 economic notes are given on two new species of wood-destroying fungi, Fomes 

 putearius and Trametes setosus, both of which are found on dead coniferous 



