. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 176 PYRENOMYCETES [CH. All the cells are uninucleate. The female cell is called by Thaxter a carpogonium or carpogonic cell in conformity with the term used for the Red Algae, but it obviously corresponds to the cell in which fertilization is now known to occur in other Ascomycetes and will therefore here be termed the oogonium. In Stigmatomyccs Baeri the trichogyne is simple (fig. 136^, e) but in many other members of the group it undergoes frequent septation and branches freely. The apices of the branches are alone receptive and may str
. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. 176 PYRENOMYCETES [CH. All the cells are uninucleate. The female cell is called by Thaxter a carpogonium or carpogonic cell in conformity with the term used for the Red Algae, but it obviously corresponds to the cell in which fertilization is now known to occur in other Ascomycetes and will therefore here be termed the oogonium. In Stigmatomyccs Baeri the trichogyne is simple (fig. 136^, e) but in many other members of the group it undergoes frequent septation and branches freely. The apices of the branches are alone receptive and may straight or spirally coiled (fig. 137). However elaborate, the trichogyne quickly disappears, collapsing and breaking off as soon as its function is fulfilled. In endogenous species the sperms are shot direct on to the trichogyne or carried to it by the water which ordinarily surrounds these filaments when the hosts are hiding in moist places. In Zodiomyces on the other hand, where the spermatia are formed externally, they fall off the parent branches on to the cup-shaped receptacle, and there appear to be sought by the trichogyne which is at first bent over (fig. 138 a) and later lifts itself after a spermatium has become attached (fig. 138^).. Fig. 137. Ci?'«/jowy<r« zi^r/zVzV/a/zw Thaxter; after Thaxter. Fig. 138. Zodiomyces vortieellarius Thaxter; trichogyne a. before and b. after attachment of spermatium; after Thaxter. In any case numerous male cells reach the trichogyne and, though the actual process of fertilization has not yet been seen, it appears likely that it is accomplished. Afterwards the oogonium divides into three superposed cells, the sterile inferior cell, the sterile superior cell and a fertile cell lying between the two (fig. 136^, Ji). This middle cell cuts off a secondary sterile cell below (fig. 136/) which like the other sterile cells is eventually destroyed. It then divides longitudinally into four "ascogenic'' cells, two of which are shown in.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectfungi, bookyear1922
