228 



ASCOMYCETES. 



as yet formed a bark. Portions of the rind become brown, 

 dry up, and peel off ; this on stronger twigs may be followed 

 by a more or less complete occlusion of the wounded part. 

 The browning also extends into the underlying wood. The 

 mycelium is found both in rind and wood, where it probably 

 obtains entrance through small wounds in the bark. In the 

 second year after infection, a circular stroma is formed in 

 the bark under the periderm. Sickle-shaped conidia are 



FIG. 111. Aglaospora taleola. Portion of cortex with embedded stromata. 

 a, Corky layer; b, after removal of corky layer; c, section of stroma. ( x f. ) 

 (After Hartig.) 



ilWw *. Pi -i^ 

 W I 



~." 3 : ':*jz 



FIG. 112. Section of stroma of Aglaospora. a, Boundary 

 of stroma formed of dark brown fungus - mycelium ; 

 I, sclerenchyma-strand of the cortex ; c, conidial cushion ; 

 d, union of necks of two perithecia. (After Hartig.) 



FIG. 113. a, Conidia ; b, asco- 

 spore of Aplaoxjiora taleola 

 ( x ifi). (After Hartig.) 



superficially abjointed from the stromata ; while embedded 

 in it are groups of perithecia with necks which join together 

 into one or a few common channels opening externally. The 

 asci contain eight spores, which are two-celled and bear five 

 thread-like appendages, one on each end, and three round the 

 median septum (Fig. 113). 



