The internal tissue of the body of the solid higher Fungi, particularly the elongated stalks (stipes) of the fructifications of the Agarics, consists of hyphae running in a longitudinal direction, which no doubt serve for the conduction of organic food substances, just as do the trumpet-hyphae, similar in appearance, though not in origin, of the higher Brown Seaweeds.
The pustules on the surface are due to fructifications, pycnidia and spermagonia.
The various sclerotia, if kept moist, give rise to the fructifications of the fungi concerned, much as a potato tuber does to a potato plant, and in the same way the reserve materials are consumed.
Gemmae, chlamydospores, resting-cells, cysts, &c.; (3) carpospores, produced by a more or less complex formative process, often in special fructifications, and subserving either or both multiplication and persistence, e.g.
Similarly with the various types of conidial or oidial "fructifications," termed pycnidia, spermogonia, aecidia, &c. In the simplest of these cases - e.g.
In other cases (Diplodia, Aecidium, &c.) conidial or oidial "fructifications" arise by a number of hyphae interweaving themselves into a knot, as if they were forming a sclerotium.
Much more complicated are the processes in a large series of "fructifications," where the mycelium first develops a densely packed mass of hyphae, all alike, in which labyrinths of cavities subsequently form by separation of hyphae in the previously homogeneous mass, and the hymenium covers the walls of these cavities and passages as with a lining layer.
Thus the roots of Sigillaria are called Stigmaria, detached leaves Sigillariophyllum, and the fructifications Sigillariostrobus; the name Sigillaria applies to the stem, which, however, when old and partly decorticated has been called Syringodendron, while its woody cylinder has often been described under the name Diploxylon.
(I) carbonaceous impressions of the leafy branches, the fructifications and other parts; (2) casts of the stem; these are usually internal, or medullary casts, as described above.
More usually, however, the carbonaceous film is thin, and merely shows the impress of the medullary cast within; (3) petrified specimens of all parts - stem, roots, leaves and fructifications - showing the internal structure, more or less perfectly preserved.
Fructifications have often been found in connexion with leafy shoots, and the anatomical structure of the axis in sterile and fertile specimens has proved a valuable means of identification.
A considerable number of Calamarian fructifications are known, preserved, some as carbonaceous impressions, others as petrified specimens, exhibiting the internal structure.
It is remarkable that fructifications apparently of this kind have been found by Renault in close association with the most ancient of the Calamarieae- Archaeocalamites.
The fructifications by themselves are not necessarily decisive, for in certain cases the supposed sporangia of Marattiaceous Ferns have turned out to be in reality the microsporangia or pollen-sacs of seed-bearing plants (Pteridosperms).
We will now describe some of the fructifications, which are grouped under generic names of their own; these genera, as having a more natural basis, tend to supersede the artificial groups founded on vegetative characters.
On the whole there is thus good evidence for the frequency of Marattiaceae in the Palaeozoic period, though the possibility that the fructifications may really represent the microsporangia of fern-like spermophytes must always be borne in mind.
- Group of Palaeozoic fructifications of Ferns or Pteridosperms.
Certain fructifications have been referred to Gleicheniaceae (Oligocarpia, fig.
Although doubts have lately been cast on the authenticity of Palaeozoic Marattiaceae owing to the difficulty in distinguishing between their fructifications and the pollenbearing organs of Pteridosperms, the anatomical evidence (stem of Psaronius) strongly confirms the opinion that a considerable group of these Ferns existed.
A longitudinal section of a male Cordaianthus (the name applied to isolated fructifications) is shown in fig.
Much further investigation will be needed before the homologies between Cordaitean cones and the fructifications of the higher Cryptogams can be established.
The class Cordaitales extends back to the Devonian, and it must be borne in mind that our knowledge of their fructifications is practically limited to representatives from the latest Palaeozoic horizons.
In the case of Walchia there is some evidence as to the fructifications, which in one species (W.