62 REPORT—1863. 
of the western district, some 5 feet thick, including a clay band of 11 inches, is thus 
divided, in a distance of two or three miles, by the increase of the parting to 18 feet, 
into the Stone Coal and the Five Quarter at Garesfield Colliery. A still more re- 
markable instance is the Tow Law seam, at the works so called, 6 feet 3 inches 
thick, which, by the increase of a parting as it goes eastward, exhibits at Bowden 
Close Colliery, only three miles away, two seams divided by no less than 16 fathoms 
of ground, in which beds of sandstone or “post” and even thin seams of coal haye 
been intercalated *. 
Such partings, when composed of shale, are often one mass of Stigmaria-impres- 
sions, and thus form no exception to the generally important part which that fossil 
plays as the root of the chief plant of the coal. But when the partings consist of 
fine-grained clean sandstone showing no trace of rootlets, I confess that the ap- 
pearance of bright solid coal resting upon them seems to me to demand some other 
explanation. Instances of this kind observed in South Staffordshire and in the 
Whitehaven Collieries induce me to think that the material must in some cases 
have been introduced between the laminze, and sometimes even diagonally athwart 
them, subsequently to the solidification of the coaly matter. 
But there are several curious phenomena as to which a doubt frequently arises, 
whether they are due to action during or after the formation of the coal; and 
deductions of no small practical importance sometimes depend on the ques- 
tion, Thus Mr, Hurstt has given a very exact account of irregularities, 
especially swellies, or narrow depressions in the Low Main coal, which appear to 
have been formed prior to the deposition of the upper seams. On the other hand, 
Mr. Marcus Scott has excellently described {| a broad valley of denudation which 
was eroded in the coals of the Shropshire field, and filled in with higher unpro- 
ductive measures. 
Again, with some of the slips and faults, or “ troubles,” we may occasionally ob- 
serve both coal and ironstone beds so to change in approaching them, or to vary 
so much on opposite sides of them, that whilst in some few cases we may be led to 
suspect their contemporaneity with the beds themselves, there are many more 
which we cannot paired without supposing that the coal must at the time of the 
disruption haye been moulded and squeezed in an almost plastic condition. 
In the determination of the plants of the coal much has been done; and the 
Newcastle names of Hutton and Witham have gained deserved honours in the 
cause. But a great deal remains to be accomplished by microscopic inquiry, and 
by the observation in the pits themselves of the pie which soon Dany particu- 
lar seams. Gdoppert tells us, of certain coals of Rhine-Prussia and Silesia, that 
different seams are distinctly formed of different plants,—sometimes Sigilaria and 
Lepidodendron, at others Coniferze, and in many Stigmaria being chiefly promi- 
nent. May we not by degrees connect the peculiar and perhaps varying character 
of seams with the special plants of which they are formed? and may we not thus 
advance to a much clearer perception of the true character of those wondrous 
primeyal forests ? 
And here I would remind you, that whilst some of our guides in coal geology 
incline to the opinion of a marine origin for their plants, thus bringing them into 
natural contact with the fishes and the probably marine shells often found in the 
shales, others insist on a terrestrial vegetation, and a third party on that of lagoons 
or sea-swamps and bogs, The last few years have given some weighty arguments 
to those who insist on a land-forest, however near to the water-level it may have 
been. We but recently know that among those giant stems of Sigil/aria the busy 
hum of flying insects and the merry chirp of the cricket were heard, that scorpions 
curled their ominous tails, that land-shells crept slimily along, and that several 
genera and many species of reptiles either pursued their prey along the ground or 
climbed the trees whose hollow trunks haye formed the casket to contain their 
remains. Here then is a goodly population to vivify the scene which only a few 
years ago was held to be almost wanting in all but vegetable life; and when we 
* This remarkable instance has been described to me by the veteran and accomplished 
iron-master, Mr. OC. Attwood. 
+ Transactions of the Institute of Mining Engineers, 1860. 
t Quart, Journ. Geol. Soc, of London. 
