As a means of protection against the Smut-Fungi which make their appearance on the different cereals, a submersion of the grains in a solution of blue vitriol (½%) for twelve hours, or better still, submerging for five minutes in water heated to 53–55° C (Jensen’s method) is employed.
Fig. 102.—Thecaphora. 1, T. convolvuli, a ball of spores, one of the brand-spores has emitted a septate branched conidiophore (× 520). 2, T. affinis, a ball of spores (× 520).
Class 3. Mycomycetes, Higher Fungi.
The Mycomycetes are not entirely aquatic in habit; they have hyphæ with transverse walls, but no sexual reproductive organs. The asexual reproduction takes place in very different ways; by endospores (in asci), conidia, basidiospores, chlamydospores, and oidia. Swarmspores are never found.
Two chief methods of reproduction may be distinguished, and hence the class may be divided into two large sub-classes:—the Ascomycetes (with asci), and the Basidiomycetes (with basidia).
Sub-Class 1. Ascomycetes.
The main characteristic which distinguishes the Ascomycetes is the ascus; a name given to a sporangium of a definite shape and size, and containing a definite number of spores. The shape is generally club-like or spherical, the number of spores 8 (in some 2, 4, 16 or more), see Figs. [103], [105], [108], [110], [113], [116], [120], [121], [123], [129].
In the lowest forms, the Exoasci, the ascus springs directly from the mycelium without the formation of a fruit-body (i.e. ascocarp). In the higher forms, which contain many species, the Carpoasci, the asci are united and form ascocarps which may be more or less enclosed (angiocarpic, hemiangiocarpic, and probably gymnocarpic).
