§37. 



STIGMARIA. 



721 



Sigillaria, except that the ring of medullary tissue possessed 

 by the latter, is wanting ; a difference, as M. Brongniart 

 remarks, precisely similar to that existing between the 

 stems or branches of a dicotyledonous tree, in which the 

 woody cylinder is associated internally with bundles of 



Lign. 162. — Stem and roots of a Sigillaria ; in a Coal mine, near 

 Liverpool. 



a, The trunk traversing a bed of coal. 



&, The roots (Stigmarice) spreading out in the underclay. 



medullary tissue, but the roots of the same tree are desti- 

 tute of them. This opinion, long since advanced by the 

 eminent French savant, was confirmed about four years ago, 

 by Mr. Binney's discovery in the coal strata at St. Helen's 

 near Liverpool, of an upright stem of a Sigillaria, nine feet 

 high, with ten roots several feet long attached, and extend- 

 ing in the underclay in their natural position (as shown in 

 Lign. 162) ; and these roots proved to be undoubted Stig- 

 marice. 



In the floor of the Victoria mine, at Dunkinfold near 

 Manchester, at the depth of 1100 feet from the surface, 



