1920] DISEASES OF PLANTS. 751 



partial smutting of a head of wheat. Three grains of this head, sown in 1910, 

 j^ave several stalks l)rnrinu: lioatls free from s-mut {Ustilano tritici). 



A disease of barley and oats, E. Foex (BuL Soc. Path. Veg. France, 6 

 {1919), No. 6, pp. 116, 118-12',).— K disease aft'ectin;: »).>tli barley and oats is 

 said to be caused by a Fusarium analogous to /''. rvhifnnosum. It sliows itself 

 like foot rot at the base of the stalk, but its mycelium is black, not Ijruwn. 



The wheat nematode, Tylenclius tritici, attacking; rye, oats, spelt, and 

 eninier, I.. I'. Byaus, A. G. Johnson, and R. W. Leukkl {I'hytopatholoyy, U 

 (1919), No. 7, pp. 2S3, 28//, pi. 1). — In continuing investigations on the eelworm 

 disease of wheat caused by T. tritici (E. S. R., 40, p. 849), an experimental plat 

 was planted in the fall of 1918 to rye, barley, oats, spelt, and emmer, as well as 

 a number of varieties of wheat. In seeding tlie crops, viable wheat nematodes, 

 in some cases free in water and in other cases normally inclosed in the galls, 

 were sprinkled or strewn with the seed when sown. The plat was kept under 

 continuous observation, and abundant infections were noted on the wheat 

 varieties, although there was some variation in regard to dilferent varieties. 

 There were also abundant infections on rye, and definite infection on oats, spelt, 

 and emmer, but no infection has yet been noted by the authors on barley. This 

 is believed to he the first record of the occurrence of nematodes on spelt and 

 emmer in the United States. 



Market patliology and market diseases of vegetables, G. K. K. Link and 

 M. W. Gakuneu iPhi/topatfioloi/y, 9 (1919), No. 11, pp. .',97-520).— The authors 

 discuss the present status of market pathology and investigations describing 

 typi's of market diseases of vegetables, in which four types are recognized, 

 slimy .soft rots due to bacteria, watery soft rots caused by Sclcrotitiia lihertiann, 

 Rhizopus rot, and gray mold rot. The diseases observed on different market 

 crops are described according to the host plants. 



Transmission of the virus of bean mosaic in seed and observations on 

 thermal death point of seed and virus, D. Redduk and V. B. Stew.\kt 

 (I'Injtopdtholo!/]/, 9 (1919), No. 10, pp. Ji.'i5-/,50). — In a previous publication 

 (E. S. R., 41, p. 155) the authors reported that the virus of bean mosaic Is 

 transmitted by the seed, and in the present publication some of the evidence 

 upon which the statement was based is recorded. Suspected seeds were disin- 

 fected and after treatment planted, and fully 50 per cent showed signs of mosaic 

 disea.se. Other varieties which are usually more susceptible to the disease were 

 tested with the same results. Heat as a possible means of controlling the dis- 

 ease was tried, hut it was found that both when u.sed with dry seed or moist 

 the death point of the seed is as low as that of the agent causing mosaic. 



Cotyledon infection of cabbage seedlings by Pseudonionas cani|)estris, 

 C. DnECHSLER (Phi/topotholony, 9 (1919), No. 7, pp. 215-282, fiys. 6).— This is a 

 detailed account of work previously noted (E. S. R., 33, p. 34G), iu which it is 

 demonstrated that infection of cabbage seedlings may take place through the 

 stomata occurring on the cotyledons. 



Is the common potato scab controllable by a mere rotation of crops? 

 M. Shapovalov (Pliytoputholofiy, 9 (1919), No. 9, pp. J,22-'i2.',, fly. 1). — An inocu- 

 lation with a strongly pathogenic struin of Actinomyces scabies on sterilized 

 filter paper in test tubes and flasks containing a synthetic .solution showed good 

 growth after the expiration of two years. This indicates that this organism 

 is able to exist for .veai's on a comparatively mo<lerate amount of cellulose 

 material in the ab.sence of a regular nutrient stratum or the host tissues, and 

 it is believed that attempts to eradicate the scab rungus by rotation of crops 

 will be unsucce-ssfuL 



