Another remarkable feature in this carboniferous plant is that it appears to have had no branches along its stem. Trunks have been found four and five feet in diameter, and have been traced to a distance of fifty, sixty, and even seventy feet, without any marks of branches being detected. Brongniart examined the portion of one stem, which, at its thicker end, had been broken across, but still measured a foot in breadth. It ran for forty feet along the gallery of a mine, narrowing to a width of not more than six inches, when it divided into two, each branch measuring about four inches across. The sigillaria stems, accordingly, must have shot up, slim and straight, to a height of sometimes seventy feet before they threw out a single branch. We know nothing of the coronal of these strangely-formed trees. From Brongniart's observations, it would seem that the upper part of the stem, like that of the lepidodendron, was dichotomous, that is, it branched out into two minor stems; but how these were disposed is unknown. We are wholly ignorant, too, of the foliage of these branches, though, from the general structure of the plant, as well as from the number of fern-fronds often found around the base of the stems, it has been conjectured that the sigillaria was cryptogamous, and, like the tree-ferns, supported a group of sweeping fronds. If so, it differed in many respects from every known member of the cryptogamic tribes. Putting together, then, all that we know of the exterior of the sigillaria, we find that it was a tall slender tree, with, palm-like, a clump of foliaged branches above, its stem bristling thickly, in at least its upper part, with spiky leaves, and its roots equally hirsute, shooting out to a distance of sometimes forty feet through the soft muddy soil. Future researches may bring us better acquainted with this ancient organism. In the meanwhile, enough of it is known to mark it out as one of the most ornate forms of vegetation that the world has ever seen. In addition to the above, the coal strata have yielded many other fragmentary remains, to which names have been given, but of which very little is known. It is pleasant, amid such a wide sea of doubt and uncertainty, to alight upon some well-known form of whose affinities there can be no question, since it still finds its representatives in living nature. Of such a kind are the coniferous stems occasionally met with in the sandstones of the coal-measures. .