ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 569 



with the fruiting forms Capnodium and Limacinia. The latter was 

 accompanied by a form of Triposporium. 



The same writer * gives an account of the mischief done to coffee 

 plants by Stilbum flavidum. He gives also a detailed description of the 

 fungus. 



Disease of Cattleya.f — Maublanc and Lasnier describe a disease 

 which attacks orchids in the hot-houses near Paris in early spring. The 

 leaves show at first small brown patches which gradually increase so as 

 to cover the whole leaf. In summer the disease gradually disappears. 

 The fungus causing the disease was found to be a Pythium. Later a 

 Glccosporium developed on the brown spots, and connected with the 

 latter by a similar mycelium they found the perithecia of Physalosphom 

 Gatthya sp. n. They consider these two to be different stages of the 

 same fungus, and to be rather in the nature of saprophytes ou the tissue 

 killed by the Pythium. 



Fairy-Rings. + — P. Hennings has been watching the formation of 

 " rings " for many years, and records his observations. Regular " rings " 

 can only be found on a flat unbroken plain either in wood or meadow. 

 Stones, roots, etc., break the symmetry of the centrifugal growth which 

 forms year after year. When the ring-forming fungus decays, it gives 

 back its nitrogenous material to the soil as manure, and a rich growth 

 of grass springs up on the site of the previous year's ring of fungi. 

 The author gives an account of the species that tend to grow in the 

 ring formation. 



Mycological Contributions^ — F. v. Hohnel explains that his studies 

 in mycology undertaken that he might gain a wider knowledge of the 

 subject, have led unexpectedly to the discovery of many new forms, as 

 well as to new observations on plants already described. The new 

 genera are : Neorehrnia, allied to the Perisporiaceaj ; TrichocoUonema 

 (Spha3ropsidea3) ; Pseudozythia and Rhyiichonectria (Nectriacese) ; 

 Rhy/ichonectrin was established to include the species Eleutheromyces 

 tonyisporus Phill. & Plowr., which is distinguished by the ciliate 

 ascospores ; Helicostilbe, a Phacostilbum, with the spiral spores of 

 Helicomyces ; CoUodochium, near to Dendrodocliium, but distinguished 

 by the catennlate spores ; Gloiosphcera, Diplorhinotrichum, and Pedilo- 

 spora (Mucedineae), Gliobotrys (Dematite). The writer also creates a 

 new genus, Pirobasidium, for the conidial form of Coryne sarcoides, 

 often wrongly described as Trerriella sarcoides. The paper includes 

 besides many new species, and notes on various well-known forms. 



Diseases of Potatoes.j| — G. Delacroix states that Phytophthora in- 



festans has been very prevalent in the neighbourhood of Paris in 



1903 ; he has examined the fungus more carefully. He describes 



also a spot disease, Pseudocommis vitis, which he thought might have 



* Bull. Soc. Mycol. France, pp. 157-64 (1 pi.). 



f Tom. cit., pp. 167-72 (1 pi.). 



% Gartenflora, liii. (1904) No. 9, pp. 228-331. See also Hedwitria. xliii. (1904) 

 pp. 92-3. § SB. Akad. Wiss.,cxi. (1902) pp. 987-1056. 



|| Ann. Inst. Nat. Agron., ser. 2, iii. (1904") pp. 1-40. See also Ann. Mycol., ii. 

 (1904) p. 299. 



Oct. 19th, 1904 2 R 



