THE OLD RED SANDSTONE. 213 
shores — those red-blooded, many-legged worms, resembling 
elongated centipedes, that wriggle with such activity among 
the mingled mud and water, as we turn over the stones under 
which they had shelterzd. Were creatures such as these the 
lords of this lower ocean? Did they enter first oa the stage, 
in that great drama of being in which poets and philosophers, 
monarchs and mighty conquerors, were afterwards to mingle 
as actors? Does the reader remember that story in the Ara- 
bian Nights, in which the battle of the magicians is described ? 
At an early stage of the combat a little worm creeps over the 
pavement; at its close two terrible dragons contend in an 
atmosphere of fire. But even the worms of the Cambrian 
System can scarce be regarded as established. The evidence 
respecting their place and their nature must still be held as 
involved in some such degree of doubt as attaches to the 
researches of the antiquary, when engaged in tracing what 
their remains much resemble —the involved sculpturings of 
some Runic obelisk, weathered by the storms of a thousand 
winters. There is less of doubt, however, regarding the 
existences of the upper group of rocks—the Silurian. 
The depth of this group, as estimated by Mr. Murchison, is 
equal to double the height of our highest Scottish mountains ; 
and four distinct platforms of being range in it, the one over 
the other, like stories in a building. Life abounded on all 
these platforms, and in shapes the most wonderful. The pe- 
culiar encrinites of the group rose in miniature forests, and 
spread forth their sentient petals by millions and tens of 
millions amid the waters; vast ridges of corals peopled 
by their innumerable builders, — numbers without number, 
—rose high amid the shallows; the chambered shells had 
become abundant — the simpler testacea still more so; ex- 
tinct forms of the graptolite, or sea-pen, existed by myriads ; 
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