Introduction to the study of fungi : their organography, classification, and distribution for the use of collectors . orless compactly side by side. Theapex of the upper cell has gener-ally a more or less conspicuoushyaline nipple in the centre. Inthis species the coat of the sporeis smooth, but in some others itis warted or spmulose (Fig. 45).The mature teleutospore maygerminate almost immediately, orin some species only after a con-siderable period of rest, in which latter case they are practicallyresting spores. The germ tube from either cell, projecting throughthe germ-pore, is at first a
Introduction to the study of fungi : their organography, classification, and distribution for the use of collectors . orless compactly side by side. Theapex of the upper cell has gener-ally a more or less conspicuoushyaline nipple in the centre. Inthis species the coat of the sporeis smooth, but in some others itis warted or spmulose (Fig. 45).The mature teleutospore maygerminate almost immediately, orin some species only after a con-siderable period of rest, in which latter case they are practicallyresting spores. The germ tube from either cell, projecting throughthe germ-pore, is at first a simple tube into which the contentsof the cell pass, and retreat to the upper end, which continuesto grow and become a promycelium. The extremity becomesdivided off from above downw^ards by one or more septa, andthen each compartment sends off a short pointed branch, whichis soon dilated at the point. This expanded end then assumesan oval or kidney shape, and receives the contents of the com-partment to which it belongs. In the course of a few hoursthese new bodies are abstricted, and become promycelial Fig. 45.—Germinating teleutosporeof Puccinia. After Tiilasne. SAPROPHYTES AND PARASITES which soon fall away. The germination of teleutosporesresults therefore in a promycelium, which develops smallsecondary or promycelial spores, and these latter are ready togerminate at once. When these promycelial spores are placedon the damp surface of the leaves of the host-plant theygerminate, and the growing point enters one of the stomata,where it forms a mycelium, the contents of the promycelialspore passing down the tube, whilst the empty spore-case soonfalls away. This new mycelium may produce spermogoniaand aecidiospores, thus reverting to the original point ofdeparture; or it may give rise to a crop of uredospores,without the intervention of aecidiospores; or it may pro-duce teleutospores, which are functionally alike or unlikethe parental teleutospores from which the pro
Size: 1486px × 1681px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcookemcm, bookcentury1800, bookdecade1890, bookyear1895
