. Comparative morphology and biology of the fungi, mycetozoa and bacteria . Plant morphology; Fungi; Myxomycetes; Bacteriology. CHAPTER III.—SPORES OF FVNGI. 95 common in the Pyrenomycetes, but further investigation of individual cases is desirable. The last remark specially applies to a considerable number of Pyrenomycetes, in which the asci have the same structure as in Sphaeria Scirpi and S. Lemaneae and elongate in the same way if they are placed singly in water when they are mature ; among these are Sphaeria inquinans and S. obducens, Schm., Cucurbitaria Labumi, and some species of Pleosp
. Comparative morphology and biology of the fungi, mycetozoa and bacteria . Plant morphology; Fungi; Myxomycetes; Bacteriology. CHAPTER III.—SPORES OF FVNGI. 95 common in the Pyrenomycetes, but further investigation of individual cases is desirable. The last remark specially applies to a considerable number of Pyrenomycetes, in which the asci have the same structure as in Sphaeria Scirpi and S. Lemaneae and elongate in the same way if they are placed singly in water when they are mature ; among these are Sphaeria inquinans and S. obducens, Schm., Cucurbitaria Labumi, and some species of Pleospora'. See Fig. 47. In all these species the membrane of the ascus consists of a thin outer layer with little power of swelling, and an inner soft gelatinous layer which swells to an unusual extent in water. If a ripe ascus is placed in water, the inner layer swells and breaks through the outer layer and protrudes in the manner described in the case of Sphaeria Scirpi. When the ascus is intact the inner layer is thin as compared with the cavity of the cell and appears to be tightly pressed between the unyielding outer layer and the protoplasmic utricle, which is tensely filled with fluid contents. As soon as the pressure upon it is relieved by the bursting of the ascus, it swells to such an extent in the direction of the longitudinal axis that the lumen is contracted into a narrow canal and the contents, whether spores or protoplasm, are driven out through the fissure. This happens in fuUy developed asci which are nearly mature, and in young half-grown asci; in both the membrane in the uninjured state is thin as compared with the wide lumen. In these species the ejection of the spores is rare, though it has been observed ; the asci when placed in water swell up at once, even after elongation, into a clouded gelatinous mass. This may be chiefly due to the fact that the asci of these land species which swell so readily have always been examined under very injurious conditions, i
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