The transverse section of the leaf diagrammatically represented in fig. 142, A, A′, shows the two stomatal grooves, _g_, and a prominent keel; the single vein consists of a small group of primary tracheae, _x_, some delicate parenchyma, and a brown patch of imperfectly preserved tissues, _a_, resembling the secretory zone tissue of a _Lepidodendron_. The whole is surrounded by a sheath of rather wide and short thinner-walled spiral or reticulate tracheids, which may be spoken of as transfusion tracheae, _t_, and compared with similar elements in the leaves of many recent Conifers. To this tissue Renault applies the epithet “water-bearing” and it is very likely that this may have been its function. The shaded portions of the lamina, in fig. 142, A, represent the distribution of thicker-walled hypodermal tissue. The section of a leaf 3 mm. wide shown in fig. 142, C, shows an almost identical structure; the transfusion tracheae are richly developed especially on the sides and lower surface of the vascular strand. This leaf occurs in association with a petrified stem of _Sigillaria scutellata_[503]. [Illustration: FIG. 200. A. _Sigillaria Brardi_ [= _S. elegans_ Brongn. (39)]. Transverse section of stem. B. _Sigillaria Brardi_ [= _S. spinulosa_, Renault and Grand’Eury (75)]: _c_³, outer cortex; _x_, _x_², xylem. (After Renault and Grand’Eury.) C. _S. Brardi_, primary xylem element. (A and C after Brongniart.) D. Leaf of _Sigillaria Brardi_: _g_, _g_, stomatal grooves; _ep_, piece of epidermis of stem. (After Renault.) E. _Sigillaria Brardi._ Tangential section of leaf-bases: _p_, parichnos. (After Renault.) F, G, H. Sigillaria leaf-scars and cushions. (After Weiss.)] Renault[504] has shown that the leaf-traces of _Sigillaria spinulosa_ (= _S. Brardi_) are accompanied in the outer cortical region of the stem by a fairly large amount of secondary xylem; in sections of the free lamina which he figures the secondary elements are much less obvious and represented by a few tracheae only. Similarly, in the leaf-base of _S. Brardi_ (fig. 200, E) the xylem consists of both primary and secondary elements (_x_, _x_²), but in the lamina the latter is poorly if at all represented. In the lamina of the leaves of _S. Brardi_ the primary xylem forms a narrow slightly curved band with two lateral groups of narrower, presumably protoxylem elements; this is surrounded by delicate parenchyma styled by Renault, on very slender evidence, phloem (“liber”). Some dark cells below the xylem are described as sclerous tissue, and surrounding the bundle is a sheath of transfusion tracheae (dotted area in fig. 200, E). It is possible that the elements spoken of with hesitation by Renault as secondary xylem are transfusion tracheae.