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In many places distinct proof is seen that the enveloping strata took years to accumulate, for some of the sandstones surrounding erect sigillarian trunks support at different levels roots and stems of Calamites; the Calamites having begun to grow after the older Sigillariae had been partially buried.
Even in the lower Permian the Lepidodendron and Sigillaria were very rare, and before the end of the epoch they and the Calamites also had become extinct.
The plants consist chiefly of zamites, calamites, equiseta, and ferns, and, upon the whole, are considered by Professor Heer to have the nearest affinity to those of the European Keuper. The equiseta are very commonly met with in a vertical position more or less compressed perpendicularly. It is clear that they grew in the places where they are now buried in strata of hardened sand and mud.
These Calamites probably rose in dense thickets from the borders of the lakes, their stumpy leaves spreading in whorls at every joint in their hollow stems. Another extinct tree, the Cordaites, rivalled the Horsetails and Club-mosses in height, and its showers of long and extraordinary leaves, six feet long and six inches in width, pointed to the higher plant world that was to come.
At the distance of 30 miles from the plumbago, there occurs, on the borders of Rhode Island, an impure anthracite in slates containing impressions of coal-plants of the genera Pecopteris, Neuropteris, Calamites, etc.
Then a new forest would spring up, the ferns, Calamites, Lepidodendrons, and Sigillarias would gradually form another jungle, and many hundred of feet above the buried coal-bed b, a second bed of peat and vegetable matter would begin to accumulate to form the coal-bed a.
In the last mentioned case, only the impression remained, but the carbonaceous matter had gone to stain the surrounding clay black, thus indicating that the dark colour of the coal-shales is due to the carbon derived from the plants which they included. Another very prominent member of the vegetation of the coal period, was that order of plants known as the Calamites.
The climate of the period, in the northern temperate zone, was of such a character that the true conifers show rings of growth, not larger, nor much less distinct, than those of many of their modern congeners. The Sigillarioe and Calamites were not, as often supposed, composed wholly, or even principally, of lax and soft tissues, or necessarily short-lived.
But the great point which is noticeable in the fossil calamites and equisetites is that they grew to a far greater height than any similar plant now living, sometimes being as much as eight feet high.
Was there ever a better type of the French nation than this old soldier? As long as fortune smiles on them, it is "Marchons au diable!" and "Vive la gloire!" Directly they get beaten, it is "Ma pauvre patrie!" and "Les calamites affreuses de la guerre!"
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