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Stigmaria ficoides, Brong. 1/4 natural size. Stigmaria ficoides, Brong. Surface of another individual of same species, showing form of tubercles. In the sea-cliffs of the South Joggins in Nova Scotia, I examined several erect Sigillariae, in company with Dr. Dawson, and we found that from the lower extremities of the trunk they sent out Stigmariae as roots.
In accordance with their outside markings, certain types are known as syringodendron, favularia, and clathraria. Diploxylon is a term applied to an interior stem referable to this family. Stigmaria ficoides. But the most interesting point about the sigillariae is the root.
At many other levels rootlets of this same plant have been shown by Principal Dawson to penetrate the clays, and to play the same part as do the rootlets of Stigmaria in the coal formation. We had already learnt from the works of Goppert, Unger, and Bronn that the European plants of the Devonian epoch resemble generically, with few exceptions, those already known as Carboniferous; and Dr.
The origin of such a vast thickness of vegetable remains, so unmixed, on the whole, with earthy ingredients, can be accounted for in no other way than by the growth, during thousands of years, of trees and ferns in the manner of peat a theory which the presence of the Stigmaria in situ under each of the seven layers of anthracite fully bears out.
They are said to form the FLOOR on which the coal rests; and some of them have a slight admixture of carbonaceous matter, while others are quite blackened by it. All of them, as Sir William Logan pointed out, are characterised by inclosing a peculiar species of fossil vegetable called Stigmaria, to the exclusion of other plants.
Some few only were based on clay and shale; none of them, except Calamites, on sandstone. The erect trees, therefore, appeared in general to have grown on beds of vegetable matter. In the underclays Stigmaria abounds.
This was for a long time regarded as an entirely distinct individual, and the older geologists explained it in their writings as a species of succulent aquatic plant, giving it the name of stigmaria.
Binney by the discovery of a tree embedded in the coal measures, and standing erect just as it grew, with its roots spread out into the stratum on which it stood. These roots were Stigmaria, and the stuff into which they penetrated was an underclay.
They differ totally from the shales and sandstones in this respect, and instead of splitting up readily into thin flakes, they break up into irregular lumpy masses. And they all contain a very peculiar vegetable fossil called Stigmaria. This strange fossil was for a long time a sore puzzle to fossil botanists, and after much discussion the question was fairly solved by Mr.
Sometimes, instead of being flat the bark is still in the shape of a trunk, and the interior is filled with sane; and then the trunk is very heavy, and if the miners do not prop the roof up well it falls down and kills those beneath it. Stigmaria is the root of the Sigillaria, and is found in the clays below the coal. Botanists are not yet quite certain about the seed-cases of this tree, but Mr.
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