FIG. 77. Nectria ditissima, a destructive parasite 

 to apple-trees, i, a branch recently attacked, the 

 disease entered at the axil of the small branch, a, a, 

 perithecia ; 2, a branch that has been diseased for 

 some time, showing a rugged callus formed round 

 the wounds : the end of the broken branch, a, is the 

 point where the fungus entered ; 3, a section through 

 a stroma containing perithecia, a, a, on its surface ; 

 4, a single perithecium ; 5, section of a perithecium ; 

 6, portion of a stroma bearing conidia; 7, a con- 

 idium germinating ; 8, portion of .the contents of a 

 perithecium ; a, an ascus containing eight spores ; 

 b, b, paraphyses. Figs, i and 2, reduced ; the 

 remainder mag. 



