British fungi : with a chapter on lichens / by George Massee.

  • George Edward Massee
Date:
[1911?]
Catalogue details

Licence: Public Domain Mark

Credit: British fungi : with a chapter on lichens / by George Massee. Source: Wellcome Collection.

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    from external dangers, but considerable evolution is evident in the way of producing a greater spore-bearing surface from an equal amount of material. In Clavaria pistillaris (Plate XXXIV, Fig. 6) we have a large, fleshy, club-shaped fungus, the even surface of which bears spores everywhere. Now if we examine Clavaria cinerea (Plate XXXIV, Fig. 5), we at once realize that it contains actually less material or weight of substance than C. pistillaris, but as the substance is broken up into numerous branches, each entirely spore-bearing throughout its surface, we grasp the fact that C. cinerea, by becoming broken up into numerous branches, can produce more spores than the heavier C. pistillaris. Clavaria aurea (Plate XXXIV, Fig. 8) illustrates to what extent branching, for the purpose of increasing the spore-bearing surface, is carried in the family. Notwithstanding the great advance made by the members of the Clavariaceae in the increase of the hymenium or spore- producing surface, by gradually breaking up a solid mass of tissue into a much-branched, tree-like structure, the idea was not per¬ petuated in succeeding families, due probably to the entire absence of protection to the hymenium, all the species growing upright, and having the hymenium exposed from first to last. In the Hydnaceae we observe a marked advance, both in securing a greater spore-bearing area, and in protecting the same. In the simpler genera, as Grandinia, the hymenial surface is densely covered with minute warts, which collectively expose a much greater area than the perfectly smooth surface in Corticium. The line of development followed is the gradual conversion of warts into densely crowded, elongated spines, as seen in Hydnum re- pandum (Plate XXVII, Fig. 7). From the protective standpoint, the fungi included in this family evolve by transitions from the crust-like expansions of Corticium, through the partly free portion as described in Stereum, to a symmetrical, umbrella-shaped structure with a central stem, and having the hymenium composed of spines arranged on the under surface of the cap, and thus protected against rain, dust, etc., as in Hydnum repandum. The conception of in¬ creasing the spore-bearing area, by covering the surface of densely crowded spines with the hymenium, dropped out with the Hyd¬ naceae ; and in the next family, the Polvporaceae, we meet with numerous pits of various degrees of depth crowded on the spore¬ bearing surface, the walls of the depressions being covered with the hymenium. In some genera, as Merulius and Polystictus (Plate XXXI, Fig. 4), the pits or pores are quite shallow, whereas in the higher species, as Boletus (Plate XXXVII, Figs, 1, 3, and 4), the pores are up to half an inch deep, or sometimes more, the wall of the entire inner surface of each pore bearing spores. The sequence of progression of the fungus ranges from a plate-like crust, as in Poria (Plate XXXI, Fig. 3), through horizontal forms, as in Polystictus (Plate XXXI, Fig. 4), to species with a convex cap,
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