COMPLEX HISTORY OF COAL. 481 
of Structure, and by details of organization, which 
shew them all to be parts of One grand, and 
consistent, and Jiarmonious Design. 
We may end our account of the Plants to 
^hich we have traced the origin of Coal, with a 
summary view of the various Natural changes, 
^ud processes in Art and Industry, through which 
can follow the progress of this curious and 
^Uost important vegetable production. 
Few persons are aware of the remote and won- 
herfid Events in the economy of our Planet, and 
cf the complicated applications of human In- 
dustry and Science, M'hich are involved in the 
production of the Coal that supplies with fuel 
''alldate the certainty of our knowledge of the entire Flora of 
ach of the consecutive Periods of Geological History, it does 
”ot affect our information as to the number of the enduring 
•ants which have contributed to make up the Coal formation ; 
as to the varying proportions, and changes in the species of 
erns and other plants, in the successive systems of vegetation 
^hat have clothed our globe. 
h may be further noticed, that as both trunks and leaves of 
^"^giospermous dycotyledonous Plants have been preserved abun- 
antly in the Tertiary formations, there appears to be no reason 
^ 7, if Plants of this Tribe had existed during the Secondary and 
'■ansition Periods, they should not also occasionally have escaped 
®struction in the sedimentary deposits of these earlier epochs. 
Loudon’s Mag. Nat. Hist. Jan. 1834, p. 34, is an account 
some interesting experiments by Mr. Lukis, on successive 
in the form of the cortical and internal parts of the stems 
Succulent plants, (e. g. Sempervivura arboreum) during various 
&es of decay, which may illustrate analogous appearances in 
fossil plants of the coal formation, 
G. 
1 I 
