36 PETRIFACTIONS AND THEIR TEACHINGS. CHAP. I. 



broken transversely, a small cylindrical core or axis is found 

 extending longitudinally throughout the stem like a medullary 

 column, \a, Lign. 9.) and there is generally a depression or 

 furrow running parallel with it on the outer surface. 1 



The nature of these fossil vegetables was long a perplexing 

 question, for no specimens had been found in connexion with 

 any of the stems, branches, or foliage, that abound in the 

 coal deposits. At length, the discovery of a dome-shaped 

 mass, from which radiated numerous stigmariae, seemed to 

 afford a clue to the solution of this botanical problem, and it 

 was concluded by the eminent Authors of the " Fossil Flora of 

 Great Britain," that the original belonged to a tribe of plants 

 which inhabited swamps, or still and shallow lakes, and were 

 characterised by a low truncated stem, having long horizontal 

 branches beset with cylindrical, and, probably, succulent 

 leaves, that either trailed on the surface of the swamp, or 

 floated in the water. 2 , 



But within the last few years, the occurrence in various car- 

 boniferous deposits, of erect stems of Sigillarise, has shown that 

 the Stigmariae are nothing more than the roots of these and 

 other congenerous trees ; an opinion maintained by the Rev. 

 H. Steinhaur more than thirty years ago, and subsequently 

 affirmed by M. Adolphe Brongniart, who found, on examining 

 microscopically the internal structure of a silicified specimen 

 in which the vascular tissue was preserved, that the organiza- 

 tion bore as close an analogy to that of the Sigillarise, as 

 exists between the roots and trunks of certain dicotyledonous 

 trees. 3 



Upright stems of Sigillarice, with Stigmaria-roots. To the 

 sagacity and persevering researches of Mr. Binney of Man- 

 chester, science is indebted for the establishment of this highly 

 interesting fact. In 1844, Mr. Binney discovered at St. 

 Helen's, near Liverpool, an erect trunk of a Sigillaria nine 

 feet high, to which were attached ten roots that extended 

 several feet into the under clay, in their natural position, and 



1 Figured in " Medals of Creation/' p. 140, PI. III. fig. 1 ; " Pictorial 

 Atlas," PI. XXI. XXIII. 



2 It is to be regretted that this erroneous conjecture is reprinted from 

 Dr. Buckland's Essay, in the recent work of Messrs. Chambers on the 

 British Museum, p. 251. 



3 See " Medals of Creation," p. 143. 



