. Botany of the living plant. Botany; Plants. CHAPTER XXVII, BASIDIOMYCETES. The Basidiomycetes form the second sub-class of the septate Eu- mycetes. They include most of the large Fungi, such as the Mush- rooms, Toad-stools, Shelf-Fungi, and Puff-Bails. These are almost all saprophytes. But the Basidiomycetes also include the Rusts and Smuts, which are parasitic forms causing disease. Some of these are the most injurious pests to cereal crops, such as the Rust of Wheat or the Smut of Oats. Some Basidiomycetes also take part in the formation of certain types of Lichens. They are thus very vari
. Botany of the living plant. Botany; Plants. CHAPTER XXVII, BASIDIOMYCETES. The Basidiomycetes form the second sub-class of the septate Eu- mycetes. They include most of the large Fungi, such as the Mush- rooms, Toad-stools, Shelf-Fungi, and Puff-Bails. These are almost all saprophytes. But the Basidiomycetes also include the Rusts and Smuts, which are parasitic forms causing disease. Some of these are the most injurious pests to cereal crops, such as the Rust of Wheat or the Smut of Oats. Some Basidiomycetes also take part in the formation of certain types of Lichens. They are thus very varied in their habit, and include many familiar objects. The characteristic feature is the Basidium, which takes a place in the life- cycle corresponding to the ascus in the Ascomycetes ; for in both of them there is nuclear reduction, and both produce post-sexual spores equivalent to Tetra- spores. But while in the ascus they are formed internally (Fig. 316, p. 417), in the the basidium have pass J \ t> ° ' r tx//j ""* four basidiospores. Z)=passage of a basidium they are borne externally, as RuhS^ Basidiospores (Fig. 328). In the Basidiomycetes normal sexuality has not been shown to exiit, while it is only in the Uredinales or Rusts that organs are found which, though not always functional as such, are held to be of the nature of sexual organs. This would indicate that the Uredinales are relatively primitive types of the Basidiomycetes. It may be held as probable that all these Fum;i were derived from a sexually reproducing ancestry ; but that the sexuality is in abeyance in the more advanced parasites and saprophytes, while evidence of it remains in the more primitive Rusts. 431 2E. Fig. 328. Honey Agaric (Armillaria mellea). A, young basidium with two primary nuclei. B, after fusion of the two nuclei. C =a basidium of Hypholoma appcndiculatum before the four nuclei derived from the secondary nucleus. Please note that these images are extracted from scanned p
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