FOUND IN COAL FROM FOKDEL. 191 



kinds of plants, some of them cellular, have entered into the composition of coal. 

 Believing Sigillarias and Stigmarias to have had a large amount of cellular tissue 

 in their structure, we can understand that in coal formed from them this tissue 

 may, in certain instances, remain more or less entire, while in other instances it 

 may have been compressed in such a way as to obliterate or rupture the cell- 

 cavities. Dotted vessels, moreover, are not so dense, nor so much thickened in 

 their walls, as woody tissue, and hence, in many cases, pressure may have in like 

 manner destroyed their characteristic appearance, and by the approximation of 

 their Avails have given rise to some of the so-called fibrous appearances in coal. 



Besides Sigillarias and Stigmarias, we also detect in the Fordel coal peculiar 

 rounded organisms, which have the appearance of seeds (Plate II., figs. 12, 13). 

 Dr Fleming informs me, that similar bodies have been observed by him in coal, 

 and that he exhibited them to Mr Witham about twenty years ago. They have 

 also been seen by Dr Fleming in Lochgelly and Arniston parrot, and in the coal 

 at Boghead ; and from having observed them in cherry, splint, and cannel coals, 

 he is disposed to consider them as a somewhat common feature. I have seen 

 them in coal from Miller-hill, near Dalkeith, as well as in the coal from Fife. 

 They do not appear to have been fully described. The nearest approach to them is 

 the Lycopodites, figured by Mr Morris in the Appendix to Mr Prestwich's paper 

 on the Geology of Coal-Brook Dale.* They appear to be certainly allied to the 

 fructification of the Lycopodiacese of the present day, more particularly to that 

 form of it which consists of two valves placed in apposition, and containing what 

 is called Lycopode-powder, or minute cells having a yellow glistening aspect, in- 

 terspersed sometimes with matter of a dark wine-colour. 



These seed-like bodies in Fordel coal (Plate II., figs. 13, 14, 15), I therefore con- 

 sider to be the sporangia or spore-cases of some plant allied to Lycopodium, per- 

 haps Sigillaria. They are remarkably preserved in the coal, and occur in many 

 instances in vast quantity. They have a rounded form, — their colour is dark 

 brown, and they seem to be formed by two valves inclosing a cavity which is often 

 filled with black carbonaceous matter (Plate II., figs. 16, 18). In some specimens 

 we remark one valve separated so as to expose a dark mass in the hollow of the 

 other valve (Plate II., fig. 16), which is imbedded in the coal. At other times, 

 when a section is made of the coal, these sporangia are cut across, and exhibit an 

 evident cavity (Plate II., figs. 17, 18). When thin sections of the coal are viewed 

 by transmittted light, the walls of the sporangia appear of a brownish or orange- 

 yellow colour (Plate II., fig. 14). 



Under the microscope, the valves often present a reticulated appearance, and 

 minute granular matter seems to be attached to the inner surface. These granules 

 I suppose to be some of the minute powdery spores slightly altered. It may be 



* Geological Transactions, v., p. 485. Plate 38, fig. 9. 

 VOL. XXI. PART I. 3 F 



