494 Mr. Logan on the Underday 



ning into indistinct rimae, like the bark of an ancient willow ; sometimes, as in the shale impressions, ex- 

 hibiting little more than a neat sketch of the concentric circles." 



In speaking of the fibres connected with these centre cylinders, Mr. Steinhauer remarks, " We were 

 soon able to detect their remains, forming considerable masses of stone, particularly coal-bind, on Web- 

 sey Slack, and at Lower Wyke, where their contorted figures imitate those of Serpulae ; but it excited 

 much surprise, on examining the projecting ends of some trunks which lay horizontally in a bed of clay 

 extending along the southern bank of the rivulet which separates the townships of Pudsey and Tong, 

 and which is exposed in several places, to find traces of these fibres proceeding from the centre cylin- 

 der in rays through the stratum in every direction to the distance of twenty feet. Repeated observa- 

 tions, and the conviction of unprejudiced persons made attentive to the phaenomena, compelled the be- 

 lief that they originally belonged to the trunks in question, and consequently that the vegetable grew 

 in its present horizontal position at a time that the stratum was in a state capable of supporting its 

 vegetation, and shot out its fibres in every direction through the then yielding mud. For if it grew 

 erect, even admitting the fibres to have been as rigid as the firmest spines with which we are ac- 

 quainted, it would be difficult to devise means gentle enough to bring it into a recumbent posture 

 without deranging their position. This supposition gains strength from the circumstance that they 

 are found lying in all directions across one another, and not directed towards any particular point of 

 the compass." 



Excepting that I never saw a mass of fibres extend to a vertical distance of more 

 than seven or eight feet from the centre cyhnder, although I believe it may range 

 to twenty and more horizontally, the latter part of this quotation describes very 

 fairly the general attitude in which every specimen is discovered in the underclays 

 of South Wales ; and when it is considered, that in so wide a district of country 

 abounding in coal, there is not a seam which is not immediately underlaid by a 

 bed wholly monopolized by these peculiar vegetable organic remains, it is impos- 

 sible to avoid the inference, that some essential and necessary connection exists 

 between the production of the one and the existence of the other. To account 

 for the unfailing combination by drift, seems an unsatisfactory hypothesis ; but 

 whatever may be the mutual dependence of the phaenomena, they give us reason- 

 able grounds to suppose that in the Stigmaria Ficoides we have the plant to 

 which the earth is mainly indebted for those vast stores of fossil fuel which are 

 now so indispensable to the comfort and prosperity of its inhabitants*. 



* It was in the summer of 1 837, when Mr. De la Beche was about to commence his survey of the district, 

 that I first pointed out to him the constant presence of the Stigmaria beds beneath the coal-seams of 

 South Wales, and his subsequent and more extended examinations have, I believe, fully confirmed my 

 own observations. Since then and since this paper was read, I have visited several other coal districts, 

 but have found no decided contradiction to any of the facts which South Wales presents. In a tour 

 through Pennsylvania in the United States of America, in August and September 1841, I detected these 

 beds under the coal-seams of the anthracite regions at Pottsville, Mauch Chunk, and particularly in the 

 coal-field of Wyoming, also at Wilkesbarre on the Susquehanna, where I remained long enough to make 

 a detailed section across the northern anthracite basin. These beds were, with one doubtful excep- 

 tion, very strongly marked, and I saw and touched them beneath upwards of thirty coal-seams, great 

 and small, and in several parts of the district widely asunder. From what I learnt in personal com- 



