248 THE ASCOMYCETES 



210, Lachnea with 180, Peziza with 160, Pezizella with 140, Pyre- 

 nopeziza with 100, Sclerotinia with 80, Ascobolus, Ascophanus, 

 Geopyxis, and Lachnella with 60 each, and iVlorchella, Elvella, 

 Sarcoscypha, and Geoglossum, \\'ith about 40 each. 



Apothecial development. The development of apothecia is 

 tv^pified by that in Pyronema confliiejis, which is among the 

 better-known representatives of cup fungi that may be found in 

 the greenhouse at the surface of pots of sterilized soil or at sites 

 of campfires or of burned brush piles. It may be recognized by 

 the groups of fiesh-colored apothecia 1 to 3 mm broad. The 

 apothecial initials are first recognizable as small hyphal tufts. 

 Within each of these tufts are thickened, erect branches, one of 

 which will become the antheridium and the other the ascogonium. 

 The ascogonial branch is slightly more precocious in develop- 

 ment, and the antheridium arises from a stipe cell beneath it. 

 While differentiating, each becomes multinucleate. 



At the apex of the antheridium a multinucleate papilla, the 

 trichogyne, is delimited; its tip curves to come in contact with 

 the tip of the ascogonium, and its nuclei gradually degenerate. 

 Then the antheridial nuclei migrate into the trichooryne. The 

 partition between the trichogyne and the ascogonium next dis- 

 solves, and the antheridial and ascogonial nuclei pair. Shortly 

 thereafter a score or more of ascogenous hyphae grow out from 

 the ascogonium, and the penultimate cell at each recurved tip 

 (crosier) becomes the ascus. Meanwhile paraphyses arise from 

 cells that are adjacent to the ascogonium. 



Among Discomycetes there are t\vo types of apothecial de- 

 velopment, gymnocarpic and angiocarpic. Differences in cor- 

 tical or marginal gro^^'th of the primordia during early develop- 

 ment account for the two types, as Corner (1929) has shown 

 that both kinds may occur \\ithin the Genus Ascobolus. Inter- 

 mediate between these t\^pes is one which Corner designates as 

 hemiangiocarpic. In these genera the marginal hyphae arch over 

 the ascogonium, but their growth is limited, in consequence of 

 which a closed sheath is not produced. Corner lists Cheiy?nenia 

 stercorea, Anthracobia melaloiiia, Ascophanus granidifonnis, and 

 Peziza aiiraiitia as hemiangiocarpic, and Ciliaria sciitellata, Ascoph- 

 miiis carneiis, Ascobolus st ere or arms , A. citrinus, A. magiiif- 

 icus, Pyronerna confluens, and Saccobohis violascens as angio- 

 carpic. 



