. Introduction to the study of fungi; their organography, classification, and distribution, for the use of collectors. Fungi. RUST FUNGI—UREDINEAE 245 - , c latter. In the one remaining genus of the section, that of Cronartium, the teleutospores surround a vertical columella, but in external appearance the species resemble Uredines as little as possible, and are not unlike persistent tendrils of some member of the Melanconieae. The Didymosporae are well typified by the large and important genus Pioccinia, with its transversely septate teleuto- spores. The grades are like those of Uromyces, viz
. Introduction to the study of fungi; their organography, classification, and distribution, for the use of collectors. Fungi. RUST FUNGI—UREDINEAE 245 - , c latter. In the one remaining genus of the section, that of Cronartium, the teleutospores surround a vertical columella, but in external appearance the species resemble Uredines as little as possible, and are not unlike persistent tendrils of some member of the Melanconieae. The Didymosporae are well typified by the large and important genus Pioccinia, with its transversely septate teleuto- spores. The grades are like those of Uromyces, viz. spermo- gonia, aecidia, uredospores, and teleutospores; but a different element comes into the subsidiary grouping, since it is con- tended that in some cases these grades are not all passed upon the same host. It is perfectly true that in one typical group,. Fig. 116.—Section of aecidia and spermogonia. that of the Auto-jpucciniae, all the grades are developed on the same species of plant; but in the Hetero-pucciniae, although all the same grades are affirmed to be present, yet the spermo- gonia and aecidia appear on one species of plant, generally a Dicotyledon; whilst the uredospores and teleutospores make their appearance on a plant belonging to quite a distinct genera of plants, mostly a Monocotyledon. Now the doctrine which associates these forms is that designated Heteroecism, and although some writers contend that the facts are not effectually proved, and therefore dispute the conclusions, others accept the inferences derived from artificial cultures as conclusive, and bow down to Heteroecism. Whichever may ultimately succeed in persuading the rest, it is manifest that Heteroecism for the present is the favourite, and consequently the faithful are happy in finding the four grades separated, two on one kind of matrix and two on another. To quote a very familiar example, the spermogonia and aecidia of the berberry are found. Please note that these images ar
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