38 
the appearance of a country where the vegetation approached in its 
conifers, gigantic lycopods and ferns (especially the tree-like) to the 
vegetation of the cosl measures. Hence we might infer a temperature 
not generally higher than the present one. 
In addition to the occasional evidence of the vegetable origin in 
sections of coal and in the coal shales, the researches of Professors 
Morris and Huxley, Mr. Carruthers, and Dr. Dawson, of Canada, 
pointed to the fact that the great bulk of the bituminous coal consisted 
of sporangia and spores of plants allied to our existing club-mosses ; in 
fact, Huxley went further, and said, “ The great mass of coal we burn 
is the result of the accumulation of the spores and spore cases of 
plants, other portions of which have furnished the carbonized stems 
and the mineral charcoal, or have left their impressions on the surface 
of the layer.” 
It appeared that thin sections of English coals from different 
localities revealed the fact that the chief elements in their composition 
were the said spores and spore cases ; the latter about 1-23rd of an inch 
in diameter, looking like little bags or sacs, more or less flattened, and 
containing the former irregularly rounded bodies, about 1-700th of an 
inch in diameter. At the next microscopical meeting he would exhibit 
slices of coal showing vegetable structure and spores. 
Looking to the spores of existing club mosses, they were found to 
contain in their coats a quantity of resinous matter, which not only 
rendered them unalterable by air and water, but caused them to be 
used for the apparently opposite purposes of artificial lightning and the 
coating of pills! Tn each case the resinous matter played the con- 
spicuous part: in the former, giving the instantaneous flash when 
blown through a flame ; in the latter, the resinous matter prevented 
the pill being wetted by the saliva, and shut out the flavour of the 
drug from the sensitive papillze of the tongue. 
The thickness of the beds of coal varied from the 10th of an inch 
to 100 feet. The thickest beds in England were no where more than 
40 feet thick. In east Germany and Styria lignite was met with over a 
hundred feet thick ; and true coal had been found in the department 
of Aveyron, Central France, over 150 feet thick. These beds generally 
rested on fine clay, penetrated in every direction by the roots of plants, 
while the beds above the coal exhibited broken leaves, twigs, and tree 
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