216 ASCOMYCETES. 



Sph. sentina (Fr.) (U.S. America). In spring of 1891 this caused at 

 Oeiseuheim ^ a severe spot-disease on the leaves of certain varieties of pear. 



Other related species occur on pear. 



There are numerous other species of Spliaerella. Saccardo gives 279 

 species, many of -which are probably more or less prejudicial to plants in 

 orchard or garden. None, however, are recorded as very injurious. 



Laestadia.^ 



This genus is similar to Sphaerella, but has one-celled 

 conidia ; it is distinguished from Fhysalospora by the absence 

 of paraphyses. 



L. maculiformis (Bon.) on living leaves of various trees. 



L. (Fhysalospora) Bidwellii (Ellis) ^ (Britain and U.S. 

 America). The Black-rot of the Vine. This parasite attacks 

 all young organs and shoots of the vine. On the leaves the 

 symptoms are spots with dark sharply-defined margins, on which 

 the pycnidia appear later as minute black pustules. The leaves 

 die, but do not fall off, as with Sphaceloma ampclinum. The 

 berries show disease when only the size of peas, and finally fall 

 off singly or in clusters. The grapes are not dusty with a 

 mealy powder, nor do they burst as in attacks of Oidium 

 Tuckeri. Two kinds of pycnidia occur: one sometimes described 

 as spermogonia, has very small rod-like conidia, borne on thread- 

 like conidiophores ; these conidia have not as yet been seen to 

 germinate. The other pycnidial form (Phoma iimcola of Berk, 

 and Curt.) contains forked filamentous conidiophores, from 

 which one-celled ovoid conidia (stylospores) are produced and 

 soon germinate by emission of a septate hypha. The latter 

 form of conidia is produced after the spermogonia, and may be 



^ Oeisenheim Jahrhuch, 1892. 



2 According to the laws of priority this genus must, as shown by Magnus 

 {Oesterreich. bolan. Zeit., 1894, p. 201), be called Garlia. Bon. 



^Bibliography: Cavara, Intomo al dissecamento dei grappoli delta vile, 1888. 



Thiimen, "Die Black-rot Krankheit d. Weintrauben." Alleg. Weinzeitung, 

 Vienna, 1891. 



Galloway and Scribner, Reports for 1888-89, U.S. Dept. of Agriculture. 



Viala and Bavaz, Les Progris agric. et viticole. Montpelier, 1888-89. 



Rathay (1), Der Blach-rot, 1891. With 19 figures (2). Bericht iib. eine nach 

 Frankreich z. Erforschung d. Black-rot Kranldieit Seise, 1891. With 7 figures (3). 

 Der White-rot in die Weinlaube, 1892. 



Viala. Die Krankheiten d. Weinstockes. 



Linhart u. Mezey, Die Krankheiten, d. Weinstockes, 1895 (Hungarian). 



U.S. Dept. of Agriculture. Numerous references in reports and bulletins, 

 where details of treatment experiments will be found. 



