ASCOMYCETES PEZIZA 



239 





of a true sexual process in the vast majority of cases. Common 

 parasites belonging to this group are the Mildews (Erysiphacece), 

 the Ergot of Rye (Claviceps purpurea, Fig. 128, A), and the 

 Vegetable Caterpillar (Cordyceps) ; but there are numerous sapro- 

 phytes, such as the ubiquitous Blue Mould (Penicillium), the 

 C u p-fungi 

 (species of Peziza, 

 Fig. 126, C), the 

 Stag's Horn 

 Fungus (Xylaria, 

 Fig. 126, A), the 

 Morel (M or- 

 chella, Fig. 126, 

 D), and Nectria, 

 which is the 

 cause of the 

 bright red pus- 

 tules so common 

 on decaying 

 branches and 

 sticks. 



A general 

 idea of the As- 

 comycetes can be 

 obtained from an 

 examination of a 

 species of Peziza. 

 The septate my- 

 celium of this 

 Fungus is peren- 

 nial and ramifies 

 in the decaying 

 substratum (e.g. dead trunks and branches, soil rich in humus), 

 its presence only becoming apparent in autumn, when conspicuous, 

 and often brightly coloured, cup-shaped fruit-bodies (apothecia, 

 Fig. 126, C) are produced at the surface. In a vertical section 

 through one of these (Fig. 127, B) the hyphae are seen to be so 

 densely compacted as to produce a false tissue, the elements of 

 which are quite irregularly arranged, except for those lining the 



FIG. 126. Fruit-bodies of various Ascomycetes. 



A, Xylaria hy poxy Ion (Stag's Horn Fungus). 



B, Geoglossum. C, Peziza (Cup-fungus). D, 

 Morchella (Morel). E,. Sclerotinia, showing 

 apothecia arising from sclerotium. 



