In surface-view a specimen figured by Hick[339] shows a number of circular scars agreeing in shape and arrangement with the rootlet scars of _Stigmaria ficoides_. At _b_ in fig. 177, A, the basal portion of a rootlet is shown in organic connexion with the outer cortex. The rootlet-bundles are given off from the stele as in other examples of _Stigmaria_; each bundle consists of a triangular strand of xylem with an endarch protoxylem at the narrow end accompanied by a portion of the secretory tissue as in the leaf-traces. As in _Stigmaria ficoides_ the rootlets are attached to the outer cortex above a cushion of small cells. It is interesting to find that rootlet-bundles, as seen in tangential section of the main axis, are associated with a parichnos strand, but this is on the xylem side of the vascular strand, whereas in the case of leaf-traces the parichnos is on the other side of the bundle. Fig. 178, A, represents a transverse section of a rootlet (6 mm. in diameter) associated with _Stigmaria radiculosa_ and probably belonging to this species. The xylem strand _x_ is composed of a group of tracheae with a single protoxylem strand, _px_, at the pointed end and with small metaxylem elements at the broad end next the space originally occupied by the so-called phloem. A parenchymatous sheath, _c′_, surrounds the bundle, and beyond this is the broad middle cortex, a small portion of which is shown on a larger scale in fig. 178, B; as Weiss points out, some of the outermost cells of the lacunar cortex (_m_) are clearly in a state of meristematic activity. The preservation of the middle cortex and the small quantity of secondary xylem are characters which this _Stigmaria_ shares with _Lepidodendron fuliginosum_, and although decisive evidence is still to seek, we may express the opinion that Weiss’s surmise of a connexion between _Stigmaria radiculosa_ and _Lepidodendron fuliginosum_ is probably correct. 5. _Lepidodendron Harcourtii._ Fig. 179, A–D.