. Comparative morphology and biology of the fungi, mycetozoa and bacteria . Plant morphology; Fungi; Myxomycetes; Bacteriology. CHAPTER III.—SPORES OF FUNGI.—GERMINATION. "3 becomes invested with a very delicate membrane of its own and appears as a small vesicle which elongates in the outward direction as the germ-tube and grows through the episporium. In the thick-walled spores of Pertusaria the tubes often ramify inside the episporium and the ramifications spread in it parallel with the surface of the spore. The canals in the membrane are, as far as can be ascertained, new formations at
. Comparative morphology and biology of the fungi, mycetozoa and bacteria . Plant morphology; Fungi; Myxomycetes; Bacteriology. CHAPTER III.—SPORES OF FUNGI.—GERMINATION. "3 becomes invested with a very delicate membrane of its own and appears as a small vesicle which elongates in the outward direction as the germ-tube and grows through the episporium. In the thick-walled spores of Pertusaria the tubes often ramify inside the episporium and the ramifications spread in it parallel with the surface of the spore. The canals in the membrane are, as far as can be ascertained, new formations at the time of germination, and are not enlargements of primordial forma- tions. They continue usually so narrow that vesicles and germ-tubes appear at first sight to be completely surrounded. On account of the slight thickness of the epi- sporium in Ochrolechia these project at an early period above the surface of the spore, and, as Tulasne observes, may often be separated with the episporium from the apparently iminjiu-ed endosporium. The use of reagents, especially Schulze's solution, shows the state of the case to be everywhere as it has been described, and this is apparent in the large spores of Pertusaria even without their use (see the explanation of Figs. 57 and 59 A, B). In all cases the spore absorbs water before the commencement of germination, and as a consequence of this it swells and forms vacuoles (Fig. 58). If it contains a reserve of food in the form of drops of oil, these are seen to decompose and disappear; the nucleus also becomes indistinguishable. As soon as the germ-tube begins to develope pro- toplasm moves into it from the spore. In many cases the germ-tube grows exclusively at the expense of the protoplasm and the reserve of food in the spore. Germination of this kind takes place when water only is present, and succeeds best in water; examples of it are to be seen especially in Fungi which lead a purely parasitic life, such as the Peronosporeae and U
Size: 1740px × 1437px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, bookpublisheroxfor, bookyear1887
