I9II-] STEVENSON— FORMATION OF COAL BEDS. 55 



Grand' Eury,"^ in the first section of his notable memoir, gives 

 the grounds on which his theory of transport is based. 



When one makes minute examination of coal, he discovers that 

 the plants have been broken up and the parts scattered ; fruits and 

 leaves are apart from the stems ; the layers of the bark are sepa- 

 rated and dispersed ; the interior parts of the stems have disap- 

 peared and the flattened cortex alone remains. The woody portions 

 of the stems have been dispersed as fusain [mineral charcoal]. 

 Stems are split and torn, Cordaitcs leaves are imperfect, everything, 

 bark or leaf, is broken up. He thinks that a great part of the tissues 

 was transformed into a kind of vegetable pulp, which makes up most 

 of certain coal beds. That this was not wholly fluid or homogeneous 

 is evident, for one may distinguish some traces of organization with 

 the microscope or even with a magnifying glass. 



The disintegration cf the plant organs occurred after death and 

 its character puts aside all suggestion of violent action. All the 

 evidence contradicts the supposition that the forests were ravaged 

 by inundations ; everything points to quiet, peaceable flow of water. 

 Most of the material was decomposed in place and carried away 

 piecemeal. The vegetable matter was not deposited in deltas within 

 either the north or the center of France. 



The preservation of stems reduced to their bark is not surprising, 

 for there was little wood in trees of the Carboniferous; but the min- 

 eral charcoal is not so easily accounted for. It seems to be fossilized 

 buried wood, dried in the air and not changed into coal. It did not 

 originate through maceration, though after formation it may have 

 been subjected to moisture, as is indicated by lack of sharpness in 

 outline. 



The vegetable disaggregation was rapid, mostly in air, and was 

 completed in swamps before removal. The conversion into detritus 

 and the quasi-dissolution were sometimes pushed very far at the 

 base of damp forests and at the bottom of swamps. The Car- 

 boniferous forests were marshy and aquatic. The plants grew 

 quickly, reached maturity and soon died. Growth had to be ener- 

 getic in order to carbonize the bark so as to make the contraction 



''■'G. Grand' Eury, " Memoire sur la formation de la houille," Ann. dcs 

 Mines., Ser. 8, T. i., Paris, 1882, pp. 101-122. 



55 



