ASCOMYCETES 



36' 



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

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

 continues till the hymenial surface becomes convex. 



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

 germinating ascospore gives rise to a thallus which bears the sporocarj 

 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 tc 



Fig. 306. — Pyronema., con/iuens Tul, A :c, carpogones ; a, antherids ; i, trxchogynes. The tri 

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

 ing from carpogone c, and cut oflF 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 ascogenou! 

 hyphx ( X about 300). (From de Bary, after Kihlman.) 



tbe 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 hyphae, occurring generallj 

 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, oi 

 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 trichogyne, with plentiful supply oi 



B B 



