q 
in the ocean of many granitic mountain chains, they do teach — 
410 CORALS AND CORAL ISLANDS. 
that there are long ranges, or lines, of volcanic ridges and 
peaks, and some of these may be among the discoveries of — 
future dredging expeditions. A range of deep-sea cones, or — 
sunken volcanic islands, would be as interesting a discovery — 
as a deep-sea sponge or coral, even if it should refuse, ex- 
cepting perhaps a mere fragment, to come to the surface in 
the dredge. 
We may also accept, with some confidence, the conclusion — 
that atolls and barrier reefs originated in the same great bal- 
ance-like movement of the earth’s crust that gave elevation — 
and cold, in the Glacial era, to high-latitude lands. If so, the — 
tropics and the colder latitudes were performing their several 
works simultaneously in preparation for the coming era; and 
it is a gain to us in our contemplations, that we hence may bal- 
ance the beauty and repose of the tropics, through all the pro- 
gressing changes, against the prolonged scenes of glacial deso- 
lation that prevailed over large portions of the continents. 

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