Diseases of plants induced by Diseases of plants induced by cryptogamic parasites; introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae diseasesofplant00tube Year: 1897 446 BASIDIOMYCETES. and forming crusts on the bark of birch. Spathulate cysti(Ua occur between the basidia. Spores colourless, and acutely ovate in shape. This is parasitic on birch. The mycelium kills and permeates the wood-parenchyma which forms the greater mass of the later-formed parts of each year-ring, with the result that the various year-rings of the wood separate from each other as concentric
Diseases of plants induced by Diseases of plants induced by cryptogamic parasites; introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae diseasesofplant00tube Year: 1897 446 BASIDIOMYCETES. and forming crusts on the bark of birch. Spathulate cysti(Ua occur between the basidia. Spores colourless, and acutely ovate in shape. This is parasitic on birch. The mycelium kills and permeates the wood-parenchyma which forms the greater mass of the later-formed parts of each year-ring, with the result that the various year-rings of the wood separate from each other as concentric hollow cylinders. The mycelium varies according as its pabulum consists of cells just killed, or of wood, or of elements in the last stages of decomposition; in this latter case it suffers from want of food. In woody elements in contact with air, or those destroyed by Polyporvs hctulinvs, the mycelium is brown and forms vesicular tyloses similar to Afiaricvji mrllcns. Polyporus betulinus Yi: (Britain and America). The sporophores are annual, and emerge as spherical structures from the unin- jured bark, or from bore- holes of Beetles, or other wounds. When mature they are hoof-like or semi- circular and short-stalked ; when dead they become soft and break off. The upper side is light-brown in colour, the pore-layer is white. A section through the sporophore shows it to be white and homogeneous without zones. Lanceolate cystidia occur between the basidia. The spores are rod-like. The pore- layer and the upper brown layer are easily detached, and strips of the remaining tissue are sometimes iitilized as razor-strops. This parasite frequents living birches, ultimately causing death. It is known to occur on both Bdula verrucosa and B. puhcsccns in Britain, America, and Europe. Its parasitism and injurious results were first demonstrated by Kostrup. ]\Iayr- investigated Rostrup, •'Snyltesvamper Aiigreb paa .Skovtraeerne,' Tidssh'i/t pa Skov- huru, 1883. -Mayi-, Botan. Central
Size: 1519px × 1317px
Photo credit: © Bookend / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
