218 ASCOMYCETES. 



Physalospora laburni (Bonord.) occurs on living twigs of Cytisus Laburnum. 

 Ph. fallaciosa Sacc. On withering leaves of Ali.'tris and Musa in Berlin 

 Botanic Garden. 



Didymosphaeria. 

 Perithecia similar to Physalospora, but with two-celled spores. 



Didymosphaeria genistae Fuck, occurs on Genista pilosa. 



D. epidermidis (Fries). On living branches of Berberis, Xnmburns, Sali.r, 

 and Eucalyptus. (Britain and U.S. America). 



D. albescens Niessl. On living branches of Zo///<-,v Xylosteviii and 

 Myri< -nrii i fjermanica. 



D. dryadis (Spegazz.). On living leaves of Dr>/us octopetala. (U.S. 

 America). 



D. populina Vuill. Prillieux and Vuillemin 1 regard this as a parasite, 

 and the cause of a peculiar dying-off of Popi/li/* ////;v/////oW/* throughout 

 Germany; Rostrup, on the other hand, ascribes this to Dothiora sphaeriodes 

 Fr. Prillieux regards Xapiiiadin m tremulae as a conidial form of 7W/////0- 

 sphacria ; Vuillemin, however, believes it to be saprophytic. 



Venturia. 



The perithecia are embedded in the stroma, and have stiff' 

 bristles round the pore ; they contain both paraphyses and 

 eight-spored asci. The spores are two-celled, with or without 

 colour. 



Venturia geranii Fr. occurs on the living leaves of Geranium 

 G. moUe, etc. 



V. rumicis (Desm.). On withering leaves of Itume.i: (Britain). 



V. maculaeformis (Desm.). On living leaves of Epilobium. 



V. vermiculariaeformis Fuck. On withered leaves of Euonymus europaeus 

 and Lonicera Xi/losteum. 



V. Straussii Sacc. et Eoum. This I have found as a parasite on Erica 

 carnea in Tyrol. It is also said to cause a disease on Ericaceae in France. 



The various conidial forms at present placed amongst the 

 "Fungi imperfecti ' as Fi(sieltti/i/n are probably related to 

 Venturia. 



Fusicladium dendriticum AVallr. on apple, and F. pirinum 

 Lib. on pear, are at present the subject of an investigation at 

 the hands of Aderhold, 2 who has, on account of their perithecia, 



1 Bullet, de hi w. mycol. de France, 1892; Coinjii. rend., 1SN!> : I\< nn mi/rot., 

 1892. 



2 Aderhold, "Die Perithecienforni v. Fit*. </< iuf,-i/ici///i" Voiiautig Mittheilung, 

 Ber. d. </< nt*<-li. I'oimi. Ges., 1894, \>. 338. 



