On the other hand the statement that annual rings occur in Palaeozoic wood is often incorrect, partial rings having been confused with regular concentric cylinders of summer elements. Dawson and Matthew[668] described rings in _D. ouangondianum_, and Goeppert and Stenzel[669], who examined the Canadian material, refer to circles like annual rings; but Penhallow[670] states that there is no evidence of true growth-rings. The medullary rays are uniseriate and consist of thin parenchymatous cells with unpitted walls; they vary considerably in depth, usually comparatively shallow but in some cases 40 or 50 cells deep. In recent Araucarineae the rays are generally shallower. The absence of special receptacles, other than occasional resiniferous tracheids, for products of secretion is a feature common to _Dadoxylon_ and the Araucarineae. The phloem presents no features of special interest, but our knowledge of this tissue is comparatively meagre. Among other examples of large _Dadoxylon_ stems some of which no doubt bore Cordaitean foliage—though as a rule we have insufficient information as regards anatomical characters to enable a decision to be made between _Cordaites_ and _Mesoxylon_—reference should be made to the imposing array of silicified trunks in the grounds of the Chemnitz Museum[671]. These were obtained from Lower Permian strata at Hilbersdorf near Chemnitz from beds overlain by porphyry tuff and resting on quartz porphyry, the volcanic material which furnished the siliceous solutions. Several large pieces of wood were found in association with stems of _Medullosa_ and _Psaronius_, leaves of _Cordaites_, _Artisia_ pith-casts, and _Cardiocarpus_ seeds with specimens of _Walchia_, _Gomphostrobus_ and other plants. Sterzel describes a stem 16·5 met. long and 1·5 met. in diameter; on the main trunk the branch-scars are scattered but on some branches there is a tendency to a whorled arrangement. This and many other stems are referred to _Araucarioxylon_ (or _Dadoxylon_) _saxonicum_, a species first described by Reichenbach as _Megadendron saxonicum_. In one specimen Sterzel states that the bordered pits are generally in 1–2 rows, though rarely in 3–4 rows, on the radial walls of the tracheids which they do not completely cover: the medullary rays reach a depth of between 20 and 30 cells. It is noteworthy that the stem 16·5 met. long has a pith-cast of the _Tylodendron_ type. _Dadoxylon_ (_Cordaites_) _Brandlingii_ (Lindley and Hutton). 1831. _Pinites Brandlingii_ Lindley and Hutton, Foss. Flor. Vol. +i.+ Pl. +i.+ 1850. _Araucarites Brandlingii_ Goeppert, Foss. Conif. p. 232, Pls. +xxxix.–xli.+ 1890. _Cordaioxylon Brandlingii_ Schenk, in Schimper and Schenk, p. 853, fig. 408.