198 



MORPHOLOG y. 



ascus, while some have 4. others 16, and some an indefinite number. 

 The asci in a perithecium are more variable. In some ascomycetes there 

 is no perithecium. 



416. The black fungi. These are very a>/nmon on dead logs, branches, 



Fig. 2310. 



Edible Morel. Morchella esculenta. The asci, forming hymenium, cover the 

 pitted surface. 



leaves, etc., and may be collected in the woods at almost any season. The 

 perithecia are often numerous, scattered or densely crowded as in Rosel- 



