SPHAEROPSIDIACEAE 



387 



SPHAEROPSIDIACEAE 



In the present order the conidia are produced within 

 a highly differentiated perithecium, resembling in many 

 essentials that present in Sphaeriaceae ; asci, however, are 



FIG. 121. Pkyllosticta prunicola, a parasite on the 

 leaves of various rosaceous fruit-trees, i, apple lea\es 

 showing holes formed by the falling away of local patches 

 killed by the fungus ; 2, section of a perithecium em- 

 bedded in the tissue of the leaf ; 3, conidia produced in the 

 perithecium. Fig. i, slightly reduced ; the others mag. 



absent, the conidia being borne on the tips of slender 

 hyphae springing from the inner cells of the perithecium. 



KEY TO THE FAMILIES 



Perithecia membranaceous, carbonaceous, or subcoria- 

 ceous, black (never soft and fleshy, and bright or clear 



