THE FUNGI WHICH CAUSE PLANT DISEASE 563 



nected but confirmation of such conclusion has not been ad- 

 duced. Connection with Coccomyces has also been reported.^^^ 



C. tubeufiana All., also on Prunus is closely like C. padi. 



C. pomi Brooks.211-212 



Acervuli pallid, subeffuse, at first subepidermal, then erumpent; 

 conidia granular, filiform, straight or 

 flexuose, 15-80 x 2-2.5 m- 



It is reported as common from 

 New Hampshire to Virginia and Michi- 

 gan on apples of almost all varieties, 

 causing small, dry, sunken, brown fruit 

 spots; a disease which had hitherto 

 been referred to a variety of causes. 

 The fungus was studied in numerous fig. sso.— Cyiindrosporium 

 culture media and its pathogenicity was p°J?}-. ,^P°''i fo™at;on in 



^ " •> artificial cultures. After 



proved by moculations. Brooks. 



C. chrysanthemi E. & D.=» 



Spots subindefinite, 1 cm. or more broad, black; acervuli innate, 

 amphigenous, 100-170 n; conidia fusoid straight, 50-100 x 3-4.5;x. 



The fungus causes dark blotches on the leaves of chrysanthemum. 



C. clematidis E. & E. 



Spots amphigenous, reddish-brown, round or subangular, 1-3 /i; 

 acervuli comparatively few, epiphyllous, immersed, scattered; co- 

 nidia fusoid-linear, 75-80 x 2.5-3 m, somewhat curved, exuding in a 

 white mass. It causes leaf spot of Clematis. ^^ Later is described 

 a variety jackmanii which differs from the species in the acervuli 

 not being confined to the spots, which are less definite, and exud- 

 ing a black mass of spores which are themselves hyaline. 



C. humuli E. & E. 



Spots amphigenous, mostly hypophyllous, small, angular, limited 

 by the veinlets, rusty brown; acervuli minute, black, amphigenous; 

 conidia nearly cylindric, granular, 40-50 x 3 m, oozing out in a 

 white mass. 



The cause of leaf spots of hops.^^ 



Other parasitic forms are: 



C. saccharinum E. & E. on maple; 



C. colchici Sacc. on Colchicum; 



C. inconspicuum Wint. on lily; 



