448 EXPERIMENT STATION HECOED. 



mors-uv(E) , the different stages in its life history being described. Suggestions 

 are given for the control of the disease, which include the pruning and destruc- 

 tion of all infected shoots and thorough spraying. It is said that young vigor- 

 ous shoots, such as are produced naturally by certain varieties or by other 

 varieties vs^here cultivation and fertilization are used, are the most subject to 

 attack. 



The mildew of g'ooseberries, G. Fron (Ann. Inst. Nat Agron., 2. ser., 8 

 (1909), No. 1, pp. 131-138, figs. 6). — The author describes the mildew of goose- 

 berries due to Sphwrotheca mors-uva\ which he says is specially destructive to 

 Ribes rubrum, R. grossularia, and R. nigrum, the fruits, leaves, and young 

 shoots being subject to attack. The characteristics of the disease caused by 

 this fungus are contrasted with those of the mildew (Microsphwra grossularice) 

 which is said seldom to attack the fruit. The introduttion and spread of the 

 disease throughout Europe is described and special attention called to it in 

 order that means may be taken to prevent its introduction into France if 

 possible. 



Diseases of deciduous forest trees, H. von Schrenk and P. Spaulding ( U. 8. 

 Dept. Agr., Bur. Plant Indus. Bui. 1.^9. pp. 85, pis. 10, figs, ii).— This bulletin 

 gives the results of several years' investigations on some of the more important 

 diseases of deciduous trees. After a brief introduction, the diseases due to 

 environmental causes such as smoke and sulphur gases, unfavorable soil condi- 

 tions, extreme cold, wind, etc., are described. The authors then discuss dis- 

 eases caused by insects, the higher plants, and miscellaneous fungi, among those 

 described being mildews, tar-spot of maple, various rusts, sycamore leaf blight, 

 leaf spots, leaf blisters, chestnut bark disease, root rots, etc. 



The most attention in the bulletin is given to diseases due to wound fungi, 

 those described being the white heart rot caused by Fomes igniarius, the red 

 heart rot caused by Polyporus sulphureus, piped rot of oak and chestnut, soft 

 rot of oaks caused by P. obtusus, heart rot due to F. nigricans, a white rot of 

 oaks due to Hydnum erinaceus, a disease of black locust caused by F. rimosus, 

 white heart rot of ash due to F. fruxinophilus, red heart rot of birch caused 

 by F. fulvus, coft heart rot of catalpa caused by Polystictus versicolor, the heart 

 rot of oaks due to F. everhartii, a white rot caused by Polyporus squamosus, 

 and several forms of sap rots due to different fungi. 



A chapter is devoted to the decay of structural timbers, in which the causes 

 and factors favoring the decay and manner of infection are described, and the 

 susceptibility to decay of different kinds of timber is shown, after which pre- 

 ventive methods are briefly described. 



A bibliography is appended. 



The catalpa leaf spot, J. B. Parker (Ohio Nat., 9 (1909), No. 7, pp. 509-512, 

 pi. 1). — The author collected in October, 1908, from a catalpa tree on the 

 campus of the Ohio State University, leaves that were affected by a leaf spot 

 disease, which was very prevalent upon the tree. A study of the material 

 showed the presence of a number of fungi. Herbarium material from several 

 sources was examined and similar species were obtained. Among the fungi 

 present were noted Macrosporium catalpw, Phyllosticta catalpa;, a species of 

 Epicoccum, and one of Cladosporium, all of which are considered as probably 

 saprophytic and to have no part in producing the spots upon the leaves. 



As a result of the author's study he is of the opinion that the fungus causing 

 the leaf spot is a new species belonging to the genus Didymosphjeria, to which 

 he has given the name D. catalpw n. sp. This is believed to be the perfect 

 form of P. catalpw. The relationship of the other fungi to the leaf spot remains 

 to be proved. 



