CHAPTER XWIII. 

 EU-MYCETES.— («) ASCOMYCETES. 



for instance the Mil- 



The Fungi belonging to the Ascomycetes, the first sub-chLss of the 

 septate Eu-mycetes, are very various in habit. Many are parasites, 

 often on leaves and stems of Flowering Plants 

 dews, such as Sphaerotheca. Others are sap- 

 rophytes, such as the small and prevalent 

 Moulds, Aspergillus and Penicillium. 

 Others again form large fruiting bodies, 

 such as those of Peziza, or the edible 

 Truffle {Tuber), or the Morel {Morchella). 

 Some are parasitic on animals, as in the 

 case of Cordyceps, which invades cater- 

 pillars and the larvae of Cockroaches. 

 The Ascomycetes are thus not only a 

 large but a very varied group of Fungi. 



Their characteristic feature is a club- 

 shaped or oval body, the Ascus, within 

 which Asco-spores usually to the number 

 of eight are contained (Fig. 362). Such 

 asci may occasionally be produced singly 

 in very simple forms, such as Sphaero- 

 theca ; but they are commonly associated 

 together in large numbers, in fruit-bodies 

 of various form. In many cases the 

 development of the asci has been found 

 to follow on the formation of sexual organs, of which the female 

 is a carpogonuim, sometimes with a receptive trichogyne, a* in the 

 Red Seaweeds. The ascosporcs may therefore be hcKl to be of the 

 nature of post-sexual carpospores. In other cases the sexual organs 



429 



1 lo. >6-- 



I'urtion u( the h>ii.rtuum ot \h« 

 .Morel {MarcktlU ettuJfnSS). «— a»i 

 /> ■-'i parapbywA. «A-.»ul>-hirmr»u»J 



livsuc. ('«a4o) (Altcf Slr«»hurifTt ' 



