l^ART II. CHAPTER XXI. 



259 



Erect Position of Trees in the Coal Strata. 



(see p. 2Q5.) all the roots would have been in the same stratum, 

 or would have been confined to certain levels, and not scattered 

 irregularly through the mass. Besides, when the stems have 

 any roots attached to them, which happens but rarely, they are 

 imbedded in sandstone precisely similar to that in which the 

 trunks are inclosed, there being no soil of different composition 

 like the Portland dirt-bed, — no line of demarcation, however 

 slight, between the supposed ancient surface of dry land and the 

 sediment now enveloping the trees. 



Some may, perhaps, think it superfluous to advance such 

 objections to M. Brongniart's theory, since Dr. Buckland has 

 informed us that, when he visited these same quarries of Treuil 

 in 1826, he saw so many trunks in an inclined posture, that the 

 occasional verticality of others might be accidental.* Neverthe- 

 less, the possibility of so many of them having remained in an 

 upright posture demands explanation ; and there are analogous 

 cases on record respecting similar fossils in Great Britain of a 

 still more extraordinary nature. 



In a colliery near Newcastle, say the authors of the Fossil 

 Flora, a great number of Sigillarias were placed in the rock as 

 if they had retained the position in which they grew. Not less 

 than 30, some of them 4 or 5 feet in diameter, were visible, 

 within an area of 50 yards square, the interior being sandstone, 

 and the bark having been converted into coal. The roots of one 

 individual were found imbedded in shale ; and the trunk, after 

 maintaining a perpendicular course and circular form, for the 

 height of about 10 feet, was then bent over so as to become 

 horizontal. Here it was distended laterally, and flattened so as 

 to be only one inch thick, the flutings being comparatively dis- 

 tinct. f Such vertical stems are familiar to our miners, under 

 the name of coal-pipes. One of them, 72 feet in length, was 

 discovered, in 1829, near Gosforth, about five miles from New- 

 castle, in coal-grit, the strata of which it penetrated. The exte- 

 rior of the trunk was marked at intervals with knots, indicating 

 the points at which branches had shot off. The wood of the 

 interior had been converted into carbonate of lime ; and its 

 structure was beautifully shown by cutting transverse slices, so 

 thin as to be transparent. (See p. 56.) 



In 1830, a slanting trunk was exposed in Craigleith quarry, 

 near Edinburgh, the total length of which exceeded 60 feet. Its 

 diameter at the top was about 7 inches, and near the base it 

 measured 5 feet in its greater, and 2 feet in its lesser width. The 

 bark was converted into a thin coating of the purest and finest 



* Bridge w. Treat., p. 471. t Lindley and Hutton, Foss. Flo., part 6. p. 150. 



