. The fungi which cause plant disease . Plant diseases; Fungi. 422 THE FUNGI WHICH CAUSE PLANT DISEASE zonate, shining, 3-10 mm. thick; tubes slender, concolorous with the context, about 1 cm. long, mouths regular, angular, 2-3 to a mm., glistening, whitish-isabelline to dark-fulvous, edges thin,. Fig. 302.— Decomposition of spruce-timber by Polyporus borealis. a, a tracheid containing a strong mycelial growth and a brownish yellow fluid which has originated in a medullary ray; at b and c the mycelium is still brownish. At d and e the walls have become attenuated and perforated, the filaments
. The fungi which cause plant disease . Plant diseases; Fungi. 422 THE FUNGI WHICH CAUSE PLANT DISEASE zonate, shining, 3-10 mm. thick; tubes slender, concolorous with the context, about 1 cm. long, mouths regular, angular, 2-3 to a mm., glistening, whitish-isabelline to dark-fulvous, edges thin,. Fig. 302.— Decomposition of spruce-timber by Polyporus borealis. a, a tracheid containing a strong mycelial growth and a brownish yellow fluid which has originated in a medullary ray; at b and c the mycelium is still brownish. At d and e the walls have become attenuated and perforated, the filaments delicate; at / the pits are almost destroyed; at g and h only fragments of the walls ; The various stages in the destruction of the bordered pits are to be followed from i to r; at i the bordered pit is still intact; at k the walls of the lenticular space have been largely dis- solved, their inner boundary being marked by a circle; at I one side of the bordered pit has been entirely dissolved; at m and n one sees a series of pits which have retained a much-attenuated wall on one side only— namely, on that which is provided with the closing membrane. In mak- ing the section a crack has been formed in this wall. Between o and r both walls of the pits are found to be wholly or partially dissolved, only at p and q has the thickened portion of the closing membrane been pre- served; at d the spiral structure of both cell-walls is distinctly recogniz- able. These walls when united form the common wall of the tracheid; at t hyphffi are seen traversing the tracheids horizontally. After Hartig. entire to toothed; spores subglobose, smooth, deep-ferruginous, 6-7 m; cystidia scanty and short; hyphse deep-ferruginous. It causes a disease of oaks. P. fruticum B. & C. occurs on living twigs of the orange and oleander in Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearan
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfungi, bookyear1913
