THE PROGRESS OF GEOLOGY IN 1842. 
The result has been that two favorite theories have been adjudg- 
ed to be, each of them, perfectly consistent with facts : viz. that 
which founded the origin of Coal measures, on the destruction of 
plants in situ — and in other instances, especially where the testa- 
ceous remains are more abundant than under circumstances to 
which the foregoing origin is applicable — from the drifting of 
large quantities of vegetable matter into estuaries and shallows. 
Of the comparitive age of each, no further proof is wanting, 
when each of the above mentioned labourers in this interesting 
field of enquiry, reports, that the fi reclay with Stigmaria ficoides 
underlies every formation which they have examined. 
This question involved many points of perplexity — and the 
result could hardly have been otherwise. It was impossible 
that two formations, deposited by precisely the same agency, 
should — o^ie of them — present a most complete overthrow of all 
vegetation ; trees torn up and buried promiscuously with re- 
mains of myriads of the finny tribes — the other — covering- 
large trunks yet standing erect, although overwhelmed ; the 
reasoning is made yet more clear upon a comprehensive view of 
Mr. Binney's labours — the Cypris of which mention was made 
in his first essay on the subject of the Manchester Coal-field*, 
appears to be both a marine and fresh-water production : it is 
clear that the associated fish partake of both characters, that is 
to say, different individuals were of distinct habits — and these 
reasons, coupled with the manner of their occurence, indicate 
pretty distinctly the circumstances of the deposit also. 
An irruption of salt water into a fresh- water estuary would 
cause destruction to both fish alike, and hence the associated re- 
mains of these two distinct classes in the same formation. As 
connected with this subject, may be classed those researches 
which relate to modern vegetable deposits, as indicative of their 
mode of formation under different circumstances ; we forbear to 
* Geologist, vol. i, p. 59. 
