Studies in Coniophora. I. The Basidium

SUMMARY

1.	More than 100 specimens filed as Coniophora in the National Fungus Collections have been examined in order to determine the developmental morphology of the basidium. These specimens, according to the identifications accepted as reasonably satisfactory, were distributed among 30 species.
2.	In all instances the basidial development in species characteristic of Coniophora has been found to involve the production of an enlarged basal vesicle with subsequent protrusion of a more slender tube from the apex of the basal enlargement. Sterigmata are then formed at the apex of the tube.
3.	In the young basidiole two nuclei are observed. These fuse as the basidiole enlarges. The fusion nucleus remains in the basal vesicle until the apical tube has elongated nearly to its ultimate length. The nucleus then migrates into the tube and divides as it nears the apex of the basidium.
4.	C. alboflavescens departs from the typical aspect by the failure of the apical protrusion to elongate much, but in all other respects the development in this species is homologous with that in other species.
5.	C. olivascens, as represented by specimens in the National Fungus Collections, has smaller spores and basidia than typical species of Coniophora and the development of the basidium is variable between the Coniophora type and the clavate type. Two of the specimens examined are probably C. mustialaensis. The others appear to represent C. olivascens, but this species may be placed more properly in Corticium or Peniophora.
6.	C. olivaceo, differs from other species of Coniophora by having cystidia, but in all other respects is a typical Coniophora and should not be a basis for maintaining the genus Coniophorella.
7.	Although they have spores similar to those of Coniophora, specimens of three species of Serpula have been found to have clavate basidia and thus do not show a very close relationship to Coniophora in this respect.