In 1842 Hawkshaw[577] described certain fossil trees, the largest of which had a circumference at the base of 15 ft., discovered, in the course of excavations for a railway in Lancashire, in soft shale at right angles to the bedding. The surface features were not sufficiently clear to enable him to decide with certainty between _Sigillaria_ and _Lepidodendron_, but while inclining to the former, it is interesting to note that the occurrence of numerous Lepidostrobi near the root led him to recognise the possibility of a connexion between the Stigmarian roots and Lepidodendron stems. In 1846 Binney gave an account of similar trees found at Dukinfield near Manchester: he spoke of one stem as unquestionably a _Sigillaria_ with vertical ribs, furrows, and scars, about 15 inches high and 4 ft. 10 inches in circumference. He expressed his conviction that “_Sigillaria_ was a plant of an aquatic nature[578].” Similar descriptions of rooted stems in the Coal-Measures of Nova Scotia were published by Brown in 1845, 1846 and 1849; in the last paper he figured a specimen, which has become famous, showing a Syringodendron stem terminating in branching Stigmarian (or possibly Stigmariopsis) roots bearing on the lower surface a series of what he called conical tap roots[579]. A similar specimen discovered in Central France nearly fifty years later demonstrated the accuracy of Brown’s description. Despite these discoveries the root-like nature of _Stigmaria_ was not universally accepted. It was, however, generally agreed that _Stigmaria_ formed the roots of _Sigillaria_; it was, moreover, held by some that _Lepidodendron_ stems also possessed this type of root, an opinion based on Brown’s record and on the occurrence of _Stigmaria_ in beds containing _Lepidodendron_ but no _Sigillaria_ stems, as in the volcanic beds of Arran and elsewhere, and on observations of Geinitz and others[580]. There is now general agreement that _Lepidodendron_ and _Sigillaria_ had the same type of “root,” though the connexion of _Stigmaria_ with the former was not so readily admitted, and indeed the evidence in support of it is still very meagre. Goeppert and other authors were unable to believe that the numerous species of _Sigillaria_ possessed roots of so uniform a type, but Goeppert, by his recognition of several varieties of _Stigmaria_, supplied a partial answer to this objection.