. Comparative morphology of Fungi. Fungi. HYPOCREALES 251 antheridium and ascogonium are formed on the same hypha; only in Claviceps there is no separation of a receptive organ, the trichogyne. The unusual degeneration of the tip of the ascogonium, however, may be connected with the fact that, like a trichogyne, it serves only for concep- tion. In this case the trichogyne, although not morphologically present, might be functionally so. Furthermore, the development of the fertilized ascogonium of Claviceps is no longer independent, a fact which can only be more definitely formulated by subseque
. Comparative morphology of Fungi. Fungi. HYPOCREALES 251 antheridium and ascogonium are formed on the same hypha; only in Claviceps there is no separation of a receptive organ, the trichogyne. The unusual degeneration of the tip of the ascogonium, however, may be connected with the fact that, like a trichogyne, it serves only for concep- tion. In this case the trichogyne, although not morphologically present, might be functionally so. Furthermore, the development of the fertilized ascogonium of Claviceps is no longer independent, a fact which can only be more definitely formulated by subsequent investigations. Our further knowledge of Claviceps is chiefly biological. In some of the biological strains peculiar changes of host occur because the main host is not in bloom when the sclerotia germinate (Stager, 1905, et seq.). Thus the sclerotia on Brachypodium silvaticum normally germinate in the spring. At this time, the panicles of this grass are still deeply ensheathed so that infection is impossible. The fungus, however, can support itself by infecting the earlier-blooming Milium effusum, which grows with B. silvaticum, and produces the Sphacelia form on the. Fig. 165.—Method of dissemination of two kinds of ergot sclerotia. 1. Sclerotia between glumes of Brachy podium sylvaticum. 2. Sclerotia on Calamagrostis epigeios. P, palea; Pi, palea inferior; Ps, Palea superior; G, awn functioning as organ of attachment; S, sclerotia; H, Tuft of hairs. (After Stager, 1922.) former as an intermediate host, although the fungus rarely reaches the development of the normal sclerotia. Meanwhile B. silvaticum has bloomed, so that the fungus may complete its development there with the sclerotial formation. Thus both hosts are necessary. We will later meet relationships of this sort in Sclerotinia and in the Uredinales. Interesting biological relationships have been found in connection with the dissemination of the sclerotia. While in the form Claviceps purpurea on rye, disseminati
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