2 STIGMARIA FICOIDES. 



would otherwise appear presumptuously dogmatic. My reasons for rejecting the 

 views of my French fellow-workers will be given in the following pages. But in 

 order to avoid needless interruptions to the continuity of my descriptions of what 

 appear to me to be facts, and of the conclusions which I think legitimately dedu- 

 cible from those facts, all controversial treatment of the subject will be limited to 

 the footnotes. 



I have not thought it necessary to re-figure the common aspects of Stigmaria 

 ficoides with its attached rootlets. Every geologist is familiar with these forms ; 

 such figures have been well supplied by Martin, 1 under the name of Phytolitkus 

 verrucosus ; by Artis 2 as Ficoidites furcatus, verrucosus, and major ; by Lindley and 

 Hutton 3 and by Corda 4 as Stigmaria ficoides. 



The first acquisition of some really scientific notions respecting Stigmaria date 

 from the publication of a memoir by Mr. (now Sir John) Hawkshaw, the distin- 

 guished engineer. When constructing the railway between Manchester and Bolton, 

 in 1837, under Sir John Hawkshaw's direction, some excavators, cutting through the 

 Carboniferous strata at Dixon Fold, near the present Clifton Station, discovered a huge 

 fossil tree with large out-spreading roots, standing vertically upon a seam of coal, 

 and soon afterwards they exposed several others in similar positions. Excellent 

 figures and descriptions of five of these trees were published by Sir John 

 Hawkshaw in 1839. 5 The largest of them was eleven feet high, seven and a half 

 feet in circumference round its top, and fifteen feet round its base. A second less 

 lofty tree exhibited four large roots radiating from its base ; each of these roots 

 soon divided, producing eight secondary roots which extended six feet from their 

 parent stem. All these fossils were coated externally with a layer of coal from a 

 quarter to three quarters of an inch in thickness. Within this coal each stem and 

 root was merely a structureless mass of clay or shale. The outer surface of the 

 coal, as well as the corresponding one of the subjacent clay, exhibited irregular 

 longitudinal flutings, but these surfaces afforded no definite evidence respecting 

 the character of the trees. This discovery established several very important facts, 

 first, that some of the largest stems of trees found in the Coal-Measures were 

 furnished with gigantic roots, which brauched dichotomously ; and second, that 

 these roots must have extended downwards through a bed of undisturbed coal ten 

 inches thick, by which the roots were abruptly cut off. It became obvious that the 

 trees must have grown where the fossils stood, and that the materials converted into 

 the bed of coal must have accumulated above their wide-spreading roots whilst those 

 trees were growing, and that subsequent changes obliterated parts of the roots. 



1 ' Petrificata Derbiensia.' 



2 ' Antediluvian Phytology.' 



3 ' Fossil Flora of Great Britain,' vol. i. 

 i ' Flora der Vorwelt.' 



5 ' Trans. G-eol. Soc. London,' 2nd ser., vol. vi, p. 173, plate xvii. 



