446 EXPERIMENT STATION RECOED. 



those noted are a stem disease of fruit trees (EutypeUa prunastri), beech 

 seedling mildew {PInjtophthora ommvora), beet and mangel rot (Sphcerella 

 tahi/ica), apple tree canker {Nectria ditissima), currant leaf spot {Septoria 

 rihis), root and stem rot of potatoes {Rhizoctonia violacea), potato leaf curl 

 (Macrosporium solani), cucumber collar rot {Ilypochnus ciicumeris), cucumber 

 leaf blotch (Tlornwdcndron hordei), and gladiolus smut (Urocystis gUidioli). 



Diseases of agricultural crops during 1910, M. L. Morten sen, Sofie 

 RosTRUP, and F. K. Ravn {Tidsskr. Landhr. Plam.tea-vl, 18 (1911), No. 2, pp. 

 317-350). — A general review of the principal plant diseases met with iu Den- 

 mark during the year. 



Some interesting plant diseases from Bulgaria, I, F. Bubak and P. Kosa- 

 ROFF {Centm. Bald, [cfc], 2. AM., 31 (1911), No. 16-22, pp. 495-502, pis. 2, 

 figs. 3). — ^The authors describe and name 5 new fungi, which are listed as 

 follows : 



Fusarium maydiperdtim n. sp. saprophytic on ears of maize, to which it is 

 \ery injurious; Phyllosticta dzumajensis n. sp. and Microdiplodia viligena n. 

 sp. both on living leaves of Vitis vinifera, neither being very injurious ; Cicin- 

 nobolus ahehnoschi n. sp. on leaves of Hibiscus csculentus ; and Coniosporinm 

 gecevi n. sp. saprophytic on ears of maize, which it blackens and otherwise 

 damages. All were found near Rusc^uk in northeastern Bulgaria. 



Observations on Marasmius oreades and Clitocybe gigantea as parasitic 

 fungi causing fairy rings, Jessie S. Bayliss (Jour. Econ. Biol., (1911), 

 No. 4, pp. 111-132, pis. 3, figs. 7). — A study has been made of the above species 

 of fungi, which commonly cause fairy rings. 



It was found that M. oreades lives parasitically on grass. It attacks young 

 roots, killing them by means of some toxic secretion. The fungus at first 

 exerts a stimulating influence, and the grass assumes a darker color owing to 

 better nitrogenous nutrition. This is believed to be due to the proteolytic 

 enzyms acting on the dead roots. There can always be distinguished a zone 

 of dark green grass outside as well as inside the zone of dead grass. The 

 infected soil was found very impervious to moisture, owing probably to the 

 air which is entangled within the meshes of the mycelium. It is thought that 

 the fungus secretes a substance toxic to itself so as not to be able to grow 

 in the same soil 3 years in succession. During the second year the fungus dies 

 and the grass gains the ascendency and flourishes owing to the increased 

 nitrogenous material available. The secretion of this toxic substance is believed 

 to account for the disappearance of rings between the places of intersection 

 when fairy rings meet. 



The conclusions for C giganfea agree in general with those given above for 

 M. oreades. 



On the diseases of cereals caused by attacks of Fusarium, M. L. JMortensen 

 (Tidsskr. Laiidbr. Planteavl, 18 (1911), No. 2, pp. 177-276).— A review of 

 present knowledge of the subject, accompanied by a comprehensive bibliography. 

 Danish experiments with the hot-water and copper-sulphate treatments ai*e 

 reported, showing that the former if sufficiently high temperatures were used 

 and the latter when correctly made were effective remedies against attacks of 

 F. nivale, while the Ceres treatment was very unsatisfactory. 



Infection experiments with the grain rust occurring on Ehamnus, F. 

 Muhlethaler (Centm. Bakt. [etc.], 2. Abt., 30 (1911), No. 16-18, pp. 386-^19, 

 figs. 4; abs. in Ztschr. Landiv. Versuclisw. Osterr., I4 (1911), No. 9, p. 1133; 

 Riv. Patol. Veg., 5 (1911), No. 8, pp. 115, 116).— The author reports infection 

 experiments with seeidia from various species of Rhamnus on a number of 

 species of grasses. He demonstrated that Piiccviiia coronata which occurs on 

 Phalaris arxindinacea in central Europe forms it lecidia on R. frangula, R. 



