254 CORDAITEAE [CH. 



Dadoxylon (Cordaites) Brandlingii (Lindley and Hutton). 



1831. Pinites Brandlingii Lindley and Hutton, Foss. Flor. Vol. I. PL I. 

 1850. Araiicarites Brandlingii Goeppert, Foss. Conif. p. 232, Pis. xxxix. XLI. 

 1890. Cordaioxylon Brandlingii Schenk, in Schimper and Schenk, p. 853, 

 fig. 408. 



This species was founded on 'a fossil giant of the vegetable 

 kingdom ' discovered at Wideopen near Newcastle in Carboniferous 

 strata on the estate of Mr Brandling. The stem, 72 ft long and 

 far from complete, showed an irregular and not a whorled distri- 

 bution of branch-scars. It is noteworthy that in D. medullaris 

 (Goepp.) 1 , a Permian species from Saxony, the branch-scars, 

 while for the most part irregularly scattered, in one case showed 

 an approach to a whorled disposition as in recent Araucarias. 

 Witham 2 gave a fuller account of the structure of the stem than 

 is included in the original description, and the species has been 

 described by many later authors from both Permian and Carboni- 

 ferous localities. The pith is discoid and the broad transitional 

 region at the inner edge of the wood is a characteristic feature 3 . 

 Thomson 4 points out that there is a tendency to a retention of 

 the scalariform type of pitting in the region of the medullary 

 rays. There are 1 5 rows of pits on the radial walls of the 

 tracheids. The rays may reach a depth of 40 cells; they are 

 usually one cell broad. It has recently been shown that as many 

 as six vascular strands 5 may form one leaf -trace instead of the 

 customary pair, a feature suggesting comparison with Meta- 

 cordaites Rigolloti Ren. with its five foliar bundles. Other species 

 agree very closely with D. Brandlingii and it is impossible to 

 determine with accuracy the precise specific limits of stems 

 agreeing generally with this type ; but for the sake of emphasising 

 the variation in anatomical structure it is worth while to draw 

 attention to a few more or less divergent forms from different 

 geographical areas. 



1 Goeppert and Stenzel (88) PI. n. fig. 14, 



2 Witham (33) A. 



3 Scott (09) B. p. 528, fig. 190. See also Penhallow (00) p. 62, with references 

 to literature. 



4 Thomson (13) p. 19 

 * Ibid. p. 16. 



