ASCOMYCETES 



369 



during growth, to permit the escape of the ascospores, and as new asci 

 are produced (mostly taking the place of older ones), the expansion often 

 continues till the hymenial surface becomes convex. 



Ascobolus, like Gymnoascus, has no intervening acrospores, and the 

 germinating ascospore gives rise to a thallus which bears the sporocarp 

 directly. It is a saprophyte, and the species abound on dung. 



6. Pyronema (Fckl.). — Pyronema confluens (Tul.) (or Peziza con- 

 fluens, Pers., as it was formerly called), which, when mature, forms a dis- 

 cocarp like Ascobolus, differs considerably from that genus in the struc- 

 ture of the carpogone and antherid, though both, doubtless, belong to 



Fig. -^od— Pyronema. conjluens Tul. A : c, carpogones ; a, antherids ; t, trichog>'nes. The tri- 

 chogyne marked t has not yet become united with a. B, older state. The tnchogyne /, proceed- 

 ing from carpogone c, and cut off by a transverse wall, is in open union with a. C : the antherid, 

 a^'is in communication through t with carpogone, c, which is swollen and emitting ascogenous 

 hypha; (x about 300). (From de Barj', after Kihlman.) 



the same main type in this respect. On the mycele of Pyronema con- 

 fluens there arise clusters or rosettes of more or less club-shaped cells 

 by forked branching at the summits of erect hyphse, occurring generally 

 in pairs ; these pairs in turn having their origin in densely branched 

 groups of hyphse. The rosettes consist each of three kinds of cell : 

 the broad club-shaped, slightly curved cells are carpogones, and are 

 usually borne on two pedicel- cells : the antherids are also club-shaped, of 

 the same height, but of about half the breadth ; and the third kind are 

 sterile cells of cylindrical form. Two or three pairs of carpogones and 

 antherids are included in each rosette. From the top of the carpogone 

 there grows forth a slender curved trichog}-ne, with plentiful supply of 



E B 



