Order 4. Pilacraceæ. The transversely divided basidia have no sterigmata, but sessile basidiospores, and fill up the cavity of a closed (angiocarpic) fruit-body as a gleba without a regular arrangement (hymenium wanting).
Pilacre fagi on the old stems of the Copper-Beech; P. petersii, on dried branches of the Hornbeam, has stalked, capitate fruit-bodies.
Fig. 161.—Tremella lutescens: I and II fruit-bodies (nat. size); III vertical section through a fruit-body; b basidia; c conidia; IV-VI basidia; VII basidiospore with a second spore; VIII a basidiospore with yeast-like budding (cultivated); IX a conidiophore. (III-IX about 400.)
Series 2. Autobasidiomycetes.
This second and larger part of the Basidiomycetes is characterised by its more highly differentiated, undivided, club-shaped, or cylindrical basidia, which generally bear 4 (seldom 2, 6, 8) apically-placed sterigmata and basidiospores (Fig. [145]). The fruit-bodies are partly gymnocarpic (in the first 3 orders and in some Agaricaceæ), partly hemiangiocarpic (in orders 3–6 of the Hymenomycetes and in the Phalloideæ, the fruit-bodies in these orders are in the young conditions more or less angiocarpic, but later on generally open below and bear the hymenium on the under surface of the fruit-body), partly also angiocarpic (in the Gasteromycetes).
Fig. 162.—Dacryomyces deliquescens: I fruit-body (nat. size); II vertical section through the hymenium; III germinating basidiospore; IV a portion of mycelium with conidia; V a germinating conidium; VI and VII chains of oidia more or less strongly magnified; VIII basidiospore of D. longisporus; IX germinating basidiospore of D. ovisporus; X and XI Calocera viscosa; X fruit-body (nat. size); XI basidia with basidiospores (highly magnified); XII Dacryomitra glossoides (nat. size).
Family 1. Dacryomycetes.
The long, club-shaped basidia bear two tapering sterigmata, which develope remarkably large basidiospores (Fig. [162] II, XI) and form gymnocarpic fruit-bodies with hymenium. 1 order: