176 ASCOMYCKTES. 



Microsphaera. 



The perithecia contain several asci with two to eight spores, 

 and the appendages have dichotomously branched ends like 

 those of Podosphaera. 



Microsphaera astragali D. C. Occurs on Astragalvs glym/- 

 pliyllos and A. virgatus (Britain and U.S. America). 



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



M. lonicerae D. C. on species of Lonicera. 



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



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



M. evonymi D. C. on Evonymus europaeus (Britain). 



M. alni D. C. on Alniis glutinosa, Betula verrucosa, and B. puhescens, 

 Rhammis caihartica, Vihurnum Opulus, and F. Lantana, etc. (Britain and U.S. 

 America). 



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

 leaves of Quercus tinctoria, etc., in North America. 



M. Guarinonii Br. et Cav. on Cystisus Lahurmtm. 



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 branched. 



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

 The Vine Mildew. 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 observed 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 Uncinula 

 spiralis. 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, Bxdletin of Torrty Botanical Club, Dec. 1894. 



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

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



Viala, Gompt. rend, cxix, 1894, p. 411. Prillieux, BvU. de la Soc. mycol. de 

 Frame, 1893. 



'B. T. Galloway {Botanical Gazette, 1895, p. 486), gives a recent account of 

 the development of this Uncinula. (Edit.). 



