Leo Lesquereux

“ A splendid specimen from the upper Devonian of Indiana, a stem half a foot in diameter, has its surface fluted exactly like that of a calamites, while its internal structure is related to that of araucaria.—The ferns have the most abundant species of the carboniferous period; already more than 600 have been described from this formation. Of these, about 200 species have been found in the coal fields of the United States, more than 50 of which appear to be indigenous or have not till now been observed in Europe. ”

“ They may have been floated by water from a distance, and may therefore, as has been supposed, represent species of plants not found in the true coal basins; but this is very doubtful. The composition of the coal flora, like the formation of the coal over immense surfaces, indicates a great degree of humidity in the atmosphere. The vapors covering the land, extending over the whole emerged surface, developed everywhere the same kind of vegetation, diversified only in its exuberance according to the composition, especially the solidity of the ground. ”

“ The calamites, which have left very abundant remains in the coal, are closely related by their hollow articulated stems with bark vertically and equally fluted, by their fructifications, and by their structure, to living species of equisetum (horsetail) . But they have the same enormous proportions in size as remarked for lepidodendron and sigillaria compared with club mosses. Their trunks vary from 1 to 6 in. in diameter, their length from 6 to 40 ft. They appear to have grown close together and in thickets, at least in some localities ”

“ The branches of calamites bear whorls of linear narrow leaves, which have been described as asterophyllites. Their fruits, Wolkmannia, are cones bearing seeds like those of species of equisetum, merely differing by the presence of scales and imbricated in rows. Two other genera, represented by branches bearing leaves also in whorls, appear referable to the same family of calamites, or perhaps to one intermediate between calamites and lepidodendron. ”

“ This seems still better evidenced by the identity of the essential vegetable types in the carboniferous formation of the whole world. On this subject, however, as on other questions concerning the distribution of the old floras, there is still a great deal of uncertainty, especially caused by insufficiency of materials for observation. ”