176 ASCOAIYCKTES. 



Microsphaera. 



The perithecia contain several asei with two to eight spores, 

 and the ai)iientlages have dichotoniously branelied ends like 

 tliose of J\i</osj)Ju(//r/. 



Microsphaera astragali D. C. Occurs on Astmr/clas glycji- 

 j>]i)llliis ;iiid A. rinjntiis (Britain and U.S. America). 



M. berberidis D. C. on Barberry (Britain). 



M. lonicerae D. C on species of Lonicera. 



M. grossulariae Wallr. on Gooseberry (Britain and U.S. America). 



M. lycii Ijasfli. on Lycium, and Desmodium (Britain and U.S. America). 



M. evonymi J). ( '. un Evonyvius europaeus (Britain). 



M. alni D. C. on Almcs glutinosa, Betula verrucosa, and B. pubescenSy 

 lUtaraMis cathartica, Vibvrnum Opvhis, and T'. La/ifana, etc. (Britain and U.S. 

 America). 



M. densissima (Schwein.)^ Thi.s species forms orbicular patches on the 

 leaves of (Inercus tinctoria, etc., in North America. 



M. Guarinonii Br. et Cav. on Cystisus Laburnun). 



Also several other American species. 



Uncinula. 



The perithecia contain several asci with two to eight spores. 

 The appendages have involute ends, and are simple or dicho- 

 tomously l^ranched. 



Uncinula spiralis B. and C- (U. S. America and Britain). 

 Thi' \'iue ^lildew. This disease was first observed in England 

 in 1845, and since then has spread over the whole of Europe. 

 The conidial stage has caused widespread injury, but the perithecia 

 remained quite unknown till 1892, when they were ob.served on 

 vines in France by Couderc, and in 1893 in large numbers by 

 Viala. In America, a similar disease is also well known ; its 

 perithecia have been long recognized and named Unciinihi 

 sjnralis. The identity of the American and European mildew 

 was first suggested by Viala in 1887, and may now be assumed. 

 The perithecia ^ when mature are brown, spherical, and beset with 



^ Atkinson, Bidhlin of Torrey Botanical Club, Dec. 1894. 



- In consequence of recent investigations, this species has been transferred from 

 the Kcnus Erysiphe, and revised with tlie author's consent. (Edit.). 



Viala, Coinpt. rend, cxix, 1894, p. 411. Prillieux, Bu//. de la Soc. mycol. de 

 France, 1893. 



^B. T. (Jalloway {Botanical Gazette, 1895, p. 486), gives a recent account of 

 the development of this Uncinula. (Edit.). 



