. Comparative morphology of Fungi. Fungi. POLYTORALES 431 according to the end forms of the different series toward which they develop. In this sense, the following ten families, whose characters will be given in the course of the discussion are different. Their probable relationships are given in the scheme on page 430. Tulasnellaceae.—Perhaps in Tulasnella we have an example of the transition from the endogenous spore formation of typical Ascomycetes to the exogenous formation in the Basidiomycetes. The family presents a series with gradual adaptation to parasitism, accompanied by the develo
. Comparative morphology of Fungi. Fungi. POLYTORALES 431 according to the end forms of the different series toward which they develop. In this sense, the following ten families, whose characters will be given in the course of the discussion are different. Their probable relationships are given in the scheme on page 430. Tulasnellaceae.—Perhaps in Tulasnella we have an example of the transition from the endogenous spore formation of typical Ascomycetes to the exogenous formation in the Basidiomycetes. The family presents a series with gradual adaptation to parasitism, accompanied by the develop- ment of the zeugite to a special storage organ. This development is analogous to that we shall find in the Auriculariales and Uredinales. The highest stage attained seems to be that reached by Cystobasidium. Tulasnella iPrototremella, Pachysterigma, Muciporus) is mostly saprophytic on bark or dead wood, occasionally parasitic on leaves. £ Q Fig. 273.— Tulasnella deliqucscens. 1, 2. Basidia with basidiospores. 3, 4. Basidia developing uninucleate conidia (X 355; after Juel, 1897.) Tulasnella helicospora. 5, 6. Young basidia. 7. Basidium with basidiospores. 8, 9. Development of basidiospores to conidia. 10. Development of conidium to secondary conidium. (After Raunkiaer, 1917.) {, T. grisea on Eichhornia speciosa in Java and T. anceps on Pteris aquilina in Europe). On the substrate they form a bloom which may thicken to a smooth corticiaceous crust. In T. deliquescens its consistency is slimy; in others, as T. thelephorea, the gelatinization of the hyphae is not marked and the consistency is waxy. T. cystidiophora, T. hyalina and T. traumatica have gloeocystidia in their hymenia and are often segregated as Gloeotulasnella. In about half the species the spores are nearly spherical while in the other half the spores are long fusiform, and sometimes curved. The hyphae are binucleate and much branched; in T. deliquescens, there are no clamps and the basidia, which are ter
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