216 ASCOMYCETES. 



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

 < M-isenheini 1 a severe spot-disease mi the leaves of certain varieties of pear. 



Other related species occur on pear. 



There are numerous other species of Spkaerella. Saccardo gives 279 

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

 in-hard or garden. None, however, are recorded as very injurious. 



Laestadia.- 



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

 conklia ; it is distinguished from Physalospora by the absence 

 of paraphyses. 



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



L. (Physalospora) Bidwellii (Ellis) 3 (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 pycniclia appear later as minute black pustules. The leaves 

 die, but do not fall off, as with Sphaceloma ampelinum. 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 

 Tucl'cri. 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 uvicola of Berk, 

 and Curt.) contains forked filamentous conidiophores, from 

 winch 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 



1 Geisenheim Jahrbuch, 1892. 



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

 (Oesterreich. hot an. Zeit., 1894, p. 201), be called Carlia. Bon. 



"Bibliography: Cavara, Intorno al dissecamento dei grappoli ililln rite, 1888. 



Thumen, "Die Black-rot Krankheit d. Weintrauben." AUj. }}'< ht~vittinif 

 Vienna, 1891. 



Oalloway and Scribner, Report* for 1888-89, U.S. Dept. of Agriculture. 



Viala and Kavaz, Lex, Proifrr-t rujric. et viticole. Montpelier, 1888-89. 



Rathay (1), D<-.r Black-rot, 1891. With 19 figures (2). Bmcht iib. erne nach 

 Frankrc.irh :. Erforschwig d. Black-rot Krankheit Reise, 1891. With 7 figures (3). 

 Der White-rot in die Weinlaube, 1892. 



Viala. Die Krankheiten d. Weinstocken. 



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



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

 where details of treatment experiments will be found. 



