. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. CH. Vlll] UREDINALES 197 of the spore forms other than the teleutospore, such as Aecidium, Caeoma and Uredo, still survive in our nomenclature. The teleutospores (figs. 164, 165, 166) may be unicellular or they may be made up of two or more cells forming a compound structure, each cell of. Fig 165- Cronnrtimit asdepiadetim Fr.; te- leutospore mass with and spores; af- ter Tulasne. Fig. 166. Mdainpsora betulina Desmaz.; germinating teleutospores; after Tulasne. which germinates independently. The teleutospore is simple in Uromyces
. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. CH. Vlll] UREDINALES 197 of the spore forms other than the teleutospore, such as Aecidium, Caeoma and Uredo, still survive in our nomenclature. The teleutospores (figs. 164, 165, 166) may be unicellular or they may be made up of two or more cells forming a compound structure, each cell of. Fig 165- Cronnrtimit asdepiadetim Fr.; te- leutospore mass with and spores; af- ter Tulasne. Fig. 166. Mdainpsora betulina Desmaz.; germinating teleutospores; after Tulasne. which germinates independently. The teleutospore is simple in Uromyces, Coleosporium, and Melampsora, it is two-celled in Gymnosporangium and Piiccinia, it is built up of three to ten superposed cells in Phraginidmm, and of a larger number in Xenodochiis. In Triphragmidium it consists of three cells laterally placed and in Chrysomyxa and Cronartium the simple teleuto- spores are so massed together as to simulate compound forms; their real nature is revealed by their early separation one from another. One-celled teleutospores occur exceptionally in the two-celled species and are known as mesospores. The teleutospores may be massed together and incrusted in the tissues of the host, or they may be detached readily from their stalks and carried by the wind or by other agencies. Further development may take place as soon as conditions are favourable, or may be delayed till after a resting period, usually till the spring following development. In either case the nucleus in each cell ultimately undergoes two successive divisions, which constitute a meiotic phase, and the daughter nuclei are separated by transverse walls, so that four uninucleate cells are produced. The teleutospore-cell thus functions as a tetrasporangium and divides into four portions, constituting the transversely septate basidium. From each cell a short, pointed branch or sterigma arises, its end dilates, a basidiospore. Please note that these images are extracted from scanned page i
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectfungi, bookyear1922
