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Thus the mixed heap of spores, leaves, and stems in the coal- forest would be persistently searched by the long-continued action of air and rain; the leaves and stems would gradually be reduced to little but their carbon, or, in other words, to the condition of mineral charcoal in which we find them; while the spores and sporangia remained as a comparatively unaltered and compact residuum.
A, Goblet inverted over a saucer; B, filled with water; C, D, specimen of earth with ague plants. Observation 6. Some Gemiasma verdaus; good specimens, but scanty. Innumerable mobile spores. Dried. Observation 7. Red dust on gray soil. Innumerable mobile spores. Dried red sporangia of G. rubra. Observation 8. White incrustation. Innumerable mobile spores. No plants. Observation 9.
The decomposition of the spores has made the shales highly bituminous, and the oil and gas have accumulated in the reservoirs of overlying porous sandstones. INVERTEBRATES. We must pass over the ever-changing groups of the invertebrates with the briefest notice. Chain corals became extinct at the close of the Silurian, but other corals were extremely common in the Devonian seas.
I well remember the first of these great storms that produced any distinct impression on my islands. The plants that followed in its wake were a few small ferns, whose light spores were more readily carried on the breeze than any regular seeds of flowering plants.
It is an inflammable material, burning with a bright flame and having much the consistence and appearance of oat-cake, which, I am informed covers a considerable area. It consists, almost entirely, of a compacted mass of spores and spore-cases.
Vaucheria has, however, a second and far higher mode of reproduction, viz., by means of fertilized cells, the true oospores, which, lying dormant as resting spores during the winter, are endowed with new life by the rejuvenating influences of spring.
The mystery of the remedial effect of quinine was also solved, as it was found that, if administered at the time which centuries of experience has shown us to be the most effective, between or shortly before the paroxysms, it either prevented sporulation or killed the spores. So that at one triumphant stroke the mystery of centuries was cleared up.
The tetanus bacillus, which is a perfect anaërobe, is widely distributed in nature and can be isolated from garden earth, dung-heaps, and stable refuse. The spores, which are the active agents in producing tetanus, are highly resistant to chemical agents, retain their vitality in a dry condition, and even survive boiling for five minutes.
Sometimes biciliated minute cells are found; without any doubt they are zoospores derived from any algoid or fungoid species. I cannot say whether there exists any genetic connection between these various sorts of spores. It seems to me that probably numbers 1-4 represent resting states of the hyphomycetes.
But we are also able to examine the texture itself of the various coals by submitting extremely thin slices to a strong light under the microscope, and are thus enabled to decide whether the particular coal we are examining is formed of conifers, horse-tails, club-mosses, or ferns, or whether it consists simply of the accumulated sheddings of all, or perhaps, as in some instances, of innumerable spores.
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