GENERAL INFEKENCES, 83 



muds, sands, and gravels of which the different beds consist ; 

 and the same agency that washed in the rocky matter would 

 likewise convey the trees and plants so abundantly diffused 

 through the mass. Fossihzed trees, stems, and branches are 

 very numerous in every coal-field. They are often traced 

 through several layers of strata, in an upright position, or but 

 little inclined to the plane of stratification. The quarries on 

 Blebo hill, at a height of six hundred feet, and directly super- 

 incumbent on the yellow sandstone of Dura Den, are full of 

 these interesting relics, — large masses of stigmaria, sigillaria, 

 coniferse, and other species of trees, and lying in every position 

 in the sandstone, from the horizontal to the vertical. Many of 

 the imbedded trees in the coal-measures of the district, from 

 the Castle-rock of St. Andrews to the highest slopes of the 

 Lomonds, are of great length, and carried into the depths or 

 shallows, might often stand hundreds of feet above the w^aters. 

 A fossilized tree was exposed in the carboniferous sandstones 

 of Blair-Adam in the summer of 1857, in an upright position, 

 the roots entire, and spreading in all directions around, about 

 fifteen feet of stem in length by four to five feet in diameter, 

 and the carbonized bark adhering over the exposed section. 

 This tree originally might measure from two to three hundred 

 feet in height ; and whether, in or out of the waters, in part or 

 in whole, the woody mass could not long resist the destroying 

 action of the elements — the currents, waves, winds, and other 

 atmospheric agencies of the period. 



Fossil trees of gigantic dimensions were, a few years ago, 

 dug out of the quarries of Craigleith and Granton, the roots 

 and some of the branches attached to the stem, and lying at 

 an angle of about twenty degrees to the horizon, as well as 

 the strata in which they were imbedded. The Purbeck " dirt- 

 beds," or old terrestrial surfaces and soils, contain at different 

 levels erect trunks, and stumps of coniferce and cycads, with 

 their roots all attached and in situ. At Beadnell, Northumber- 

 land, large areas in the coal-measures are covered with roots 



