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162 EXPLOITATION OF PLANTS 
following year, and maintained his (Dawson’s) original 
thesis, that in the coals of Nova Scotia and New Bruns- 
wick, at least, spores were relatively unimportant, but 
that the barks of Sigillarias, and Calamites, and other 
great forest trees of the Coal Measures were the principal 
source of the bright layers. Since those days many 
researches on coal have been published in many coun- 
tries, yet it still remains woefully true, as Parkinson said 
in 1804, that ‘‘ Among the humiliating proofs of our 
limited powers of inquiry, there are few which are more 
striking than that which is manifested by the ineffi- 
ciency of our investigations relative to coal.”” Though 
to Huxley’s question, ‘‘ Why does not our English coal 
consist of stems and leaves to a much greater extent 
than it does ¢’’ we can answer to-day that it does con- 
sist of stems and leaves to a much greater extent than 
he knew. 
The vegetable origin of coal is indubitably true, and 
whether you accept Frémy’s theory that coal is a 
structureless plant jelly, Huxley’s view that it is chiefly 
made of spores, or White and Thiessen’s view that it 
“is chiefly composed of residue, consisting of the most 
resistant components of plants, of which resins, resin 
waxes, waxes, and higher fats, or the derivatives of the 
compounds composing these are the most important,” 
or my view that ordinary coal is preponderatingly com- 
posed of variously preserved plant mummies—you will 
all be agreed as to its vegetable origin. 
Hence, recalling the vast practical uses of coal, we 
see that for all these wonders we are indebted to plants. 
We use, or waste, every year the energy and the products 
which were stored in the plant bodies of long ago. So 
