Immunofluorescent techniques have demonstrated a difference in surface components of hyphae and rhizoids of Allomyces macrogynus. An antigenic component detected on the rhizoidal surface may be present, but masked, in the hyphal-wall matrix material. The system also allows visualization of the hyphal wall during aging, when changes from a smooth to a fissured surface are noted, and differences in adsorptive properties occur.

Of 10 geographic strains of Flammulina velutipes, 4 were found capable of fruiting at 22°C (FrH) rather than at the typical 15°C (FrL). Crosses made between FrH and FrL monokaryons were never observed to fruit at 22°C. However, some hybrids did fruit at the intermediate temperature of 18°C when grown on appropriate substrates, indicating incomplete dominance of the low-temperature requirement. Analysis of progeny of five FrH x FrL crosses indicated that a minimum of two genes appears to control the requirement for fruiting at

SUMMARY The ultrastructure of the Conchocelis or filamentous stage of Porphyra leucosticta was investigated. Each cell contains 1 or 2 parietal, stellate chloroplasts with a single pyrenoid in each chloroplast. The centrally located nucleus is irregularly shaped and contains 1–2 nucleoli. The cytoplasm has typical floridean starch grains and nonmernbrane‐bound lipid bodies. The cell wall is divided into an outer and an inner wall. Many lomasomes are associated with the cell membrane. Pit connections are found between cells, and their taxonomic significance is discussed.

The endosymbiotic marine protist Nephromyces was first classified as a chytridiomycete by Giard in 1888, yet its taxonomic affinities with chytridiomycetes, as well as with other groups traditionally considered fungi, remain in doubt. To supplement the morphological data on which taxonomic inferences have been based, we assayed Nephromyces for chitin, using three methods: chromatographic assays of acid hydrolysates of alkali-resistant cell residues; infrared spectral analysis; and observations of N-acetylglucosamine-specific lectin-binding properties of the surfaces of living cells. All three assays indicate the presence of chitin in Nephromyces. The possible phylogenetic implications of this finding are discussed.

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