DISEASE CAUSEDfBY FUNGI 



2ol 



On the other hand, many plants that are presumably 

 healthy and robust are attacked by true parasitic fungi ; 



FIG. 52. Phoma sanguinolcnla, a fungus belong- 

 ing to the Sphaeropsidiaceae, parasitic on carrot, i, 

 a carrot root attacked and partly eaten away by the 

 .fungus ; 2, stem of carrot attacked by the fungus ; 

 3, portion of a diseased spot showing perithecia with 

 the conidia being discharged in tendrils ; 4, section 

 of a perithecium with the conidia oozing out as a 

 gelatinous tendril. Figs, i and 2, reduced ; figs. 3 

 and 4, highly mag. 



among such are all the members of the Uredineae, the 

 Ustilagineae, and many species belonging to the Ascomy- 



