844 EXPERIMENT STATION EECOED. 



E. L. Vincent (pp. 276-303) ; Commerce in Rubber, by H. Wright (pp. 304-324) ; 

 and Industrial Use of Rubber, by G. Lamy-Torrillion (pp. 325-350). 



DISEASES OF PLANTS. 



Bacterial diseases of plants, M. C. Potter (Jour. Agr. Set., ^ {1912), No. 3, 

 pp. 323-337). — This is a paper read before the British Association for the 

 Advancement of Science as an introduction to the discussion of plant diseases 

 due to bacteria, in which the author gives a general description of the patho- 

 genic properties of some of the more typical forms. 



Plant diseases and crop rotation, H. L. Bolley {Northwest. Miller, 8'J {1912), 

 Nos. 10, pp. 565, 566, 585, figs. J,; 11, pp. 623, 62.',, G.',l, 6J,2, jigs. //).— This is a 

 discussion of the relation of certain fungi causing diseases of cereals, flax, 

 etc., to their host plants, and the necessity of crop rotation to avoid continued 

 loss is pointed out. Previous accounts of the author's work along this line have 

 been noted elsewhere (E. S. R.. 25, p. 649). 



Notes on veg'etable patholog-y, E. Griffon and A. Maublanc {Bui. Trimesf. 

 Soc. Mycol. France, 21 {1911), No. 1, pp. 1,7-67, figs. 3).— After giving a discus- 

 sion of a disease of the Christmas rose, Helleborus niger, ascribed to Cfmiothy- 

 rium Jicllebori, brief reports and discussions are given of various plant diseases 

 and their progress during 1910. 



Notes on vegetable pathology, E. Griffon and A. Maublanc {Bui. Trimest. 

 Soc. Mycol. France, 27 {1911), No. J,, pp. J,69-.',75).—T\\q authors state that the 

 tumescent growths observed on melons, celery, and garden sorrel near Nantes 

 and ascribed by E. Marchand to the presence of Plasmodiophora brassicw are 

 really caused by Heterodera radicicola. They also give brief notes on certain 

 diseases of the inne, olive, and pear. 



Plant diseases of 1909—10, N. J. Giddings {West Virginia Sta. Rpt. San Josd 

 Scale, etc., 1909-10, pp. J,9-52). — Brief notes are given on a number of diseases 

 observed upon apples, cherries, grapes, peaches, pears, plums, potatoes, etc. 



Okra wilt (fusariose), Pusarium vasinfectuni, and clover rhizoctoniose, 



F. L. Stevens and G. W. Wilson {North Carolina Sta. Rpt. 1911, pp. 70-73, 

 figs. 1/). — A description is given of the okra wilt caused by F. vasinfeetum, a 

 disease which apparently has not been hitherto recorded in North Carolina. 

 In general the disease agrees closely with the wilt of cotton. The fungus when 

 isolated grows readily in cultures, producing the characteristics which agree 

 with those of F. vasinfectuni on cotton. 



During the season covered by the report complaints were received from a 

 number of localities regarding a disease of clover. An examination of the roots 

 showed that they were infested by Rhizoetonia sp., which was clearly the cause 

 of the trouble. 



The present status of the question of rust propagation, J. Beaxjverie {Ren. 

 Gen. ScL, 23 {1912), No. 3, pp. 106-118). — A critical review is given of literature 

 relating to the general subject of rust propagation, specialization, etc., the sum- 

 mary being brought down to 1911. Special attention is given to Eriksson's 

 mycoplasm theory and Zach's criticism of it (E. S. R.. 25, p. 652). 



Perennial gametophytic and sporophytic g'enerations in Puccinia obtegens, 

 E. W. Olive {Abs. in Science, n. ser., 35 {1912), No. 891, p. 150). — A description 

 is given of a form of this rust, better known under the name of P. suaveolens, 

 which was found at Brookings, S. Dak., on an European variety of the Canada 

 thistle. As commonly described, this fungus is said to possess 2 distinct gen- 

 erations, one resulting from a general infection throughout the whole plant, 

 and the second a strictly local infection, in which only uredospores and teleuto- 

 spores are produced. 



