TUANSACTIONS OF SECTION C. 



741 



external evidence is advanced to support it. The latter is more conceivable from 

 the standpoint cf evolution, and is not contradicted Ly any evidence that lias yet 

 come under the aut jr's observation. 



7. On the Structure of English and American Garhoni/crous Coals. 

 Bi) P:dward Wethkrep, F.G.S., F.G.S. 



Tiie author had examined several seams of coal from England and America. He 

 pointed out that they were not always made up of one continuous bed of coal, but 

 ol'teu comprised several distinct beds. In the case of the well-luiown Welsh ' four 

 feet' seam there were four distinct strata of coals, separated by clay beds of a 

 few inches thick. In the case of the ' Splint Coal ' from Whitehill Collieiy, near 

 Edinburgh, the seam presented three clearly defined beds of coal, but these were 

 not separated by partings of any kind. 



With a view of testing tiie 'Spore Theory' of tlie origin of coal, as propounded 

 by Professor Huxley, the author had obtained a portion of the ' better bed ' seam 

 intact for a thickness of 10 inches from the top. lie had examined this inch by 

 inch, by preparing thirty-three microscopic sections. At the top was JJi inches of 

 dull lustrous coal, termed ' laminated coal.' This the author found to be 

 practically a mass of macrospores and microspores. Below this there was a change 

 in tlie character of the seam. Spores became less numerous; in places they were 

 scarce, the mass being made up of vegetable tissue and a substance to which the 

 author gives the term ' hydrocarbon.' He could not, therefore, support Professor 

 Huxley in saying that the * better-bed ' coal was ' simply the sporangia and spore 

 cases of plants.' The assertion would, however, apply to the first oi inches ot the 

 seam. Tiie ' splint coal ' from Whitehill Colliery was a better example of a spore 

 coal than the ' better-bed.' Tiie bottom stratum wsis 4 inches thick, and presented 

 a dull lustre with thin bright layers traversing at intervals. The dull portion was a 

 mass of spores and spore cases, but these did not enter the bright layers. A vertical 

 section cutting a bright layer, bounded on either side by dull lustrous coal, showed 

 plenty of spores in the dull coal, but in the bright not one was detected. The 

 second bed in this seam was 1 foot thick ; it was of a brighter lustre than the 

 4 inches below, but two layers could be distinctly made out, one more lustrous 

 tiian the other. In the dullest of the two spores were found, which, however, were 

 less numerous than in the bed below, and were, also, of a different variety. In the 

 bright layers the spores were absent. The top bed of the seam was also 1 foot 

 tliick, and might bo defined as a mass of spores, chietiy microspores, except in the 

 bright layers. The American coals examined were collected by the author from 

 the Warrior Coalfields of Alabama, and from near Pittsburg, Pennsylvania. The 

 same structural aflinities were noticed as in the English coals, and the author 

 therefore came to the conclusion that the Ihiglish and American Carboniferous 

 coals had a common origin. 



Tile spores in the coal from both coimtries were closely allied. Some micro- 

 spores from Alabama were identical with those which occur in the lower bed of the 

 Welsh ' four feet' seam. A feature in spores obtained I'rom all the coals was the 

 triradiate markings which they exhibited. Whether this was to be regarded as 

 superficial or not, it was very characteristic of them, and was, therefore, to be con- 

 sidered in attempting to ally them with modern vegetation. 



The author regarded peat in the light of post-tertiary coal ; lignite as peat in a 

 transition state to coal ; and coal as the remains of carboniferous bogs. 



The author referred to the practical application of a knowledge of the micro- 

 scopic structure of coal, as enabling an expert to judge of the nature of a coal from 

 nn examination of it with a pocket lens 



8. Second Report on the Fossil PhyUopoda of the Palaeozoic Roclcs. 



Sec Reports, p. 75. 





II 



