PYRONEMA 



367 



tered by the wind. No sexual reproduction has been discovered 

 in Peziza, but in Pyronema, a form similar to Peziza, sexual 

 reproduction has been 

 discovered and carefully 

 followed. 



Pyronema. In this 

 form there are sex organs 

 and the apothecium de- 

 velops as a result of 

 fertilization (Fig. 318). 

 The female sex organ 

 resembles that of the 

 simpler Red Algae, such 



as Nemalion. It consists of a globular cell (oogonium) and an 

 elongated tube-like cell (trichogyne or conjugating tube). The 



FIG. 318. Sexual reproduction in Pyronema confluans. A, the sex organs 

 at the time of fertilization, showing the antheridia (a) in contact and fusing 

 with the trichogynes through which the sperms pass to the oogonia (o) ; B, de- 

 velopment of apothecium, showing the oogonia developing ascogenous hyphae 

 which are beginning to form asci at the ends of their branches, and the sterile 

 hyphae (6) which grow up among the ascogenous hyphae and form a large 

 part of the wall of the apothecium. Highly magnified. After Harper. 



antheridium is a somewhat club-shaped terminal cell which 

 comes in contact with the tip of the trichogyne and fuses with 

 it. Both oogonium and antheridium are multinucleate. The 



