DISEASES OF PLANTS. 44*7 



lio.-irt rot attacks the central leaves ami works down into tbe crown of the root, 

 while the dry rot ai»i)ears on the sides of the root, usually on those portions not 

 furnished with rootlets. 



The use of certain fertilizers is said to favor the development of the disease, 

 nitrate of soda being particularly detrimental in this respect. A moist soil also 

 favors the disease throuf^h the production of an active growth. 



The internal disease of the potato, A. S. Horne {Ann. Mycol., 7 {1909), No. 

 3, pp. 2S6-288). — A preliminary note is given of a disease of potatoes variously 

 known in parts of England as "bruise" and "internal disease." Tubers 

 aftecte<l with this disease show no external characteristic symptoms. The flesh 

 remains firm, but is marked to a greater or less degree with dark brown specks, 

 blotches, or streaks, rendering the tubers useless. 



A study of the trouble showed that it was due to an organism which exists 

 within the cells of the host. The organism, which is provisionally regarded as 

 a Chytridiaceous fungus, begins growth as a small vesicle within the cell, being 

 attached to the cell wall by a fine thread. These vesicles increase in size and 

 in the storage cells become wedged among the contents. The vegetative body 

 gives rise to one or more spheres, which vary in appearance according to the 

 degree of development. 



The composition of potatoes attacked by Phytophthora, G. Riviere and G. 

 Railiiachk {Jour. S(x: Nat. Hart. France, J/, .scr., JO {1909), June, pp. 349, 

 3')0). — According to the authors the glucose in potatoes attacked by P. infestans 

 amounts to 8.5 parts in 1,000 of the pulp as compared with 4 parts in 1,000 for 

 the sound potatoes. It is believed that this difference is due to the action of 

 diastases secreted by the mycelium of the fungus, which causes a sacchariflcation 

 of a certain amount of the starch. 



A new anthracnose of figs, F. L. Stevens and J. G. Hall {Ztschr. Pflanzen- 

 Icranlc, 19 {1909), No. 2, pp. 65-68, pi. /).— The authors describe a disease of 

 figs that is said to occur in eastern North Carolina. The fruits and leaves are 

 attacked and a rot of the fruit is caused which in general resembles the bitter 

 or ripe rot of the apple. The cause of the trouble was found to be a species of 

 Colletotrichum, to which the name C. carica n. sp. is given. 



Inoculation experiments with cultures of the organism showed that the char- 

 acteristic spotting of the fruit could be produced in a few days in a moist atmos- 

 phere, and the climatic conditions of eastern North Carolina are said to be such 

 as to favor the growth of the fungus. 



A leaf disease of the olive, L. Petri {Atti. R. Accad. Lincei, Rend. CI. Set. 

 Fvi., Mat. c Nat., G. scr., 18 {1909), I, No. 11, pp. 620-623, figs. 2).— In April, 1909, 

 there was reported from several regions in Italy a destructive leaf disease of the 

 olive, in which portions of the leaves were discolored and the tissues of the 

 leaf dead. A study of the material showed that the trouble was due to the 

 fungus PhijIIosticta insulata. The gross characters of the disease resemble in 

 a marked degree those caused by Coniothyrium olece and Stictis paniz::ei, both 

 of which have been reported upon olive leaves. The author thinks it probable 

 that these diseases have been confused and that P. insulata is the cause of 

 much of the injury hitherto attributed to the others. An amended description 

 of the species is given. 



The fungi of yerba mate, C. Spegazzini {An. Mns. Nac. Buenos Aires, 3. ser., 

 10 (1909), pp. lU-Uil, figs. 8). — Descriptions are given of fungi occurring on 

 the Paraguay tea {Ilex paraguayensis), 72 species being technically described, 

 a number of which are new. In a preliminary statement regarding these para- 

 sites notes are given on a few of the more common and destructive forms. 



American g-ooseberry mildew {Jour. lid. Agr. [London], 16 (1909), No. 2, 

 pp. 117-125). — An account is presented of gooseberry mildew (Sphwrotheca 



