DISEASES OF PLANTS. 351 



but that it is a disease due to some unknown organism. If this organism is a 

 fungus, it is thought that it probably exists only in a vegetative condition, and 

 that its hyphge are very diminutive, making it difficult to distinguish in the 

 host tissue. 



Notes on some mildews, E. Foex (Ann. Ecole Nat. Agr. MontpelUer, n. sen, 

 11 (1912), Nos. 3, pp. 2'iG-2I,8, fig. 1; J{, pp. 2Jf9-26J,, pi. 1, figs. 5).— Notes are 

 given on the formation of conidiophores of species of Erysiphaceae ; on the pres- 

 ence of two kinds of conidiophores in Oidiopsis taiirica, a parasite of sainfoin ; 

 and on O'idium alphitoides, the mildew that has been so abundant in Europe 

 on the oaks within the past few years. 



The specialization of Uromyces caryophyllinus, E. Fischer (2Iycol. Centbl., 

 1 (1912), yo. 1, pp. 1, 2). — In continuance of previous work (E. S. R., 24, p. 

 346), the present brief preliminary report states that the author tested the 

 supposition that this fungus falls into several species living on different hosts. 

 It is claimed that in repeated tests this fungus was successfully cultivated on 

 Tunica prolifera but not on Saponaria ocymoides, and the conclusion is reached 

 that here are two forms biologically distinct. 



Corrosive sublimate as treatment for winter grains, L. Hiltnee and 

 Gentneb (PraJd. BI. Pflanzenbau u. Schiitz, n. sen, 9 (1911), No. 9-10, pp. 117, 

 118). — In pursuance of studies by the senior author on corrosive sublimate as 

 protection from attacks of Fusarium, resulting from infected seed (E. S. R., 

 25, pp. 548, 652), observations were made on the ci'op of 1911. 



It is stated that the percentage of attack was found not less than in the 

 previous year, notwithstanding it is probable that more sublimate was used in 

 1911, but the authors claim that the degree of infection was lower. The re- 

 ports show that in ease of early sowings of rye a better stand of plants was 

 obtained from the seed that had been first soaked in the sublimate solution. 

 A later report on this subject is promised. 



A wheat head disease, G. Fron (Jour. Agr. Prat., n. ser., 23 (1912), No. 11, 

 pp. 340-SJi2, figs. 2). — Illustrations and a brief description are given of a 

 disease of wheat in France said to have been known there for about 30 years, 

 but now becoming serious in some sections. The disease attacks the head. 

 In some cases, only the middle portion is affected, but in severer cases the 

 whole head is deformed and dwarfed, the chaff being flecked with black spots 

 or covered with a dark mycelium which prevents development of all grains ex- 

 cept possibly those at the ends of the spike. The affection is ascribed to the 

 fungus Dilophia graminis. The author urges further studies of the disease. 



Leaf roll of potato (Ztschr. Landw. Versuchsio. Osterr., 14 (1911), No. 7, 

 pp. 911-915, pi. 1, fig. 1). — This is the third report of the committee appointed 

 for the studj^ of this disease. The symptoms are fully described in order to 

 prevent confusion between this and somewhat similar affections. Such means 

 of combating the disease as chemical treatment of seed tubers, disinfection 

 of the soil, and use of special fertilizers, are stated to have been found thus 

 far of negative or at best of doubtful utility. Early removal from the field 

 of tubers from diseased plants and careful culling of seed tubers are recom- 

 mended as practical measures that are in a degree protective. 



The wart disease of potatoes, T. H. Middleton (Bd. Agr. and Fisheries 

 [London], Ann. Rpt. Intel. Div. 1910-11, pt. 2, pp. 38-54, waps 2).— The wart 

 disease of potatoes, due to Synchytrium endoUoticnm, is present over a large 

 area covering the west and northwest of England, parts of Wales, and a 

 part of Scotland. 



Experiments with about 50 different varieties were carried on in 1910 in 

 different localities to determine their resistance to the disease, with gratifying 

 results. The varieties Langworthy, Conquest, and Golden Wonder were not 



