The xylem is therefore centripetal in origin as in _Sphenophyllum_ and in nearly all recent and fossil members of the Lycopodiales. In the type-specimen of _Cheirostrobus_ the vascular cylinder of the cone consists entirely of primary xylem, but secondary xylem has been found in a more recently discovered specimen[17]. Secondary xylem occurs also in the peduncle of the cone. No appreciable remains of phloem have been found. The cortex consists of slightly elongated rather thick-walled tissue containing secretory sacs. Crowded superposed whorls of bracts (or sporophylls), usually twelve in each whorl, are borne on the axis and each sporophyll receives a single vascular bundle from one of the vertical ridges of the xylem column (fig. 117, A, _lt_). The members of each whorl are connate at the base: from this narrow collar each sporophyll branches into an upper or dorsal and a lower or ventral limb (fig. 117, A, _f_ and _s_). Each limb divides palmately at a short distance from its origin into three slender segments, which extend in a horizontal direction and terminate in large laminar expansions (fig. 117, B, _s_) to afford a protective covering to the surface of the cone. The upper set of three segments, constituting sporangiophores (fig. 117, A, B, _f_) or fertile divisions of the sporophyll, expand distally into comparatively bulky laminae; each of these bears on its adaxial face four diagonally placed outgrowths which form the short pedicels of very long and narrow sporangia. The three lower segments—the sterile divisions of the sporophylls—(fig. 117, A, B, _s_) are similar to the upper set except in their greater length and in the kite-shaped form of their distal laminae which are provided with lateral lobes. The single vascular strand which supplies each sporophyll is represented at _lt_ in fig. 117, B; at _lt′_ the strand has divided into four, the three upper bundles in the figure supply the sterile segments and the single lower bundle ultimately divides into three which supply the fertile segments. A pair of blunt processes (fig. A, _s_) extend downwards over the ends of the underlying fertile lamina and two slender prolongations extend upwards through several internodes. [Illustration: FIG. 117. A, B. _Cheirostrobus pettycurensis_ Scott. (After Scott.) C, D. _Pseudobornia ursina_ Nath. (After Nathorst.) A. Diagrammatic radial longitudinal section of part of the cone-axis and two sporophylls. _lt_, bundle passing out to sporophyll; _f_, fertile segment of sporophyll showing two sporangia; _s_, sterile (lower) segment. B. Part of transverse section. _x_, stele; _lt_, _lt′_, bundles on their way to sporophylls; _a_, tips of sterile segments of lower sporophylls. C. Palmately branched leaf (½ natural size). D. Node of stem showing leaf-bases.]