THE FOBMAHOU OF COAL-SEA MS. 



673 



are the JStigmarice, it is almost proof positive that these trees grew 

 on the spot, because we find the same kind of fossils in the underclays. 

 When erect fossil stems or stools of trees are met with, they are 

 generally either resting npon or at no great distance above the tojps 

 of coal-beds, though the largest and most perfect examples of such 

 fossils have occurred in beds far removed from coal *. The absence 

 of them in the underclays is conclusive evidence that they very 

 seldom if ever grew there ; and the fact of their very rare occurrence 

 in the coal itself further strengthens the argument against a groivtJi- 

 in-situ formation of coal, at all events from trees. And when we 

 find, as we do, impressions of the bark of large trees upon the base 

 of a coal-seam next to the underclay, it is clear that the vegetable 

 matter was transported from a distance. 



d. Does a vertical section of a coal-seam afford any clue to the 

 way in which it was accumulated ? It seems to me that when we 

 find that the structure, from top to bottom, is strictly a laminated one, 

 that every layer, division, "bench," or what not, and every line or 

 film observable in the " grain " of coal lies parallel to the plane of 

 the seam, there is not a tittle of evidence that the coal-forming plants 

 grew on the spot. Take a sample of coal from whatever locality you 

 will, and from any part of any coal-seam, and its characteristic 

 grain or laminae will be seen if carefully looked for. I have never 

 yet in all my experience detected or heard of more than one or 

 two upright forms of fossil stems (?) in coal : and I maintain that 

 if trees grew in large quantities where the coal-beds now are, their 

 erect remains would have materially interfered with the parallelism 

 of the coal as existing. That pre-existing interruptions in this 

 universal lamination can have since been obliterated by pressure or 

 by metamorphism seems highly improbable. The groivtli-in-situ, 

 difficulty would also seem to be increased when we bear in mind that, 

 spreading over very large areas of some of our coal-fields (measured by 

 square miles in extent), there are conspicuous and comparatively thick 

 layers of spore-coal, consisting almost wholly of macrospores, every 

 one of which lies horizontally. Where, it must be asked, are the 

 remains of the stumps of the trees from whose branches these myriads 

 of seeds or seed-cases were shed ? A satisfactory explanation of the 

 cause or origin of the perfect lamination of coal, and of the phe- 

 nomena of "partings" or distinct bedding-planes by which so many 

 seams of coal are divided and subdivided, and of the insinuation of 

 thin layers of clay into the seams, has yet to be given. 



e. Occurring occasionally in some of the underclays in Leicestershire 

 and South Derbyshire are well-vrorn boulders and pebbles of quartzite 

 and quartz which have been transported from a distance f. 



But besides boulders and the fossil Stigmarice, the fireclays some- 

 times contain fragments of the stems of tree-ferns, leaves, and other 

 plants of a peculiar nature : Anthracosice also have been noticed 



* I refer particularly to the "'fossil trees" recentlv found at Clayton and at 

 Bradford, Yorks.— W. S. G-. 



t In the underbed of the Coalburg seam in West Virginia, U.S.A.. rounded 

 quartz-boulders have been found. 



