184 
ORIGIN OF LIFE IN AMERICA 
existing coast line of the Atlantic States south of Massachu¬ 
setts was submerged (Fig. 14). I look upon the indigenous 
animals and plants of Bermuda as relicts of an ancient fauna 
and flora. I hold, moreover, that Bermuda furnishes us with 
one of the most instructive facts of the exceedingly slow 
Change that many species of animals and plants undergo 
through successive geological ages, and that it does not sup¬ 
port the theory advocated by Dr. Wallace that many organisms 
possess the power of crossing seven hundred miles of open 
sea. 
The geology of Bermuda, so far as the visible structure is 
concerned, is identical with that of the Bahamas, except that 
the coral reefs are of greater importance in the latter. The 
rocks in both are limestone, and red clays resulting from its 
decomposition. Nearly all the rooks of Bermuda above 
sea-level, and to a considerable depth below it, are made up of 
wind-drifted shell sand with very little material derived from 
corals and other organisms. These materials, according to 
Professor Verrill, when consolidated, form a trueaeolian lime¬ 
stone. The island is surrounded by coral reefs in such a 
manner as to give it the appearance of an atoll of the Pacific 
Ocean. It was actually regarded as such by Professor Rice.* 
The greater Bermuda or “ Pliocene Bermuda ” as it has 
been called, which was once dry land, had an area of about two 
hundred and thirty square miles. That this greater Bermuda 
represents an older land surface was revealed during the exca¬ 
vations made in 1870 for harbour works. These extended to 
over fifty feet below sea-water level. At a depth of forty- 
six feet, as Mr. Jones y tells u r s, a stratum of peat and red 
earth two feet thick was found, containing the vertical stumps 
of cedar trees. This again rested on hard aeolian limestone, 
containing fossil land shells of the genus Poecilozonites. 
There is clear evidence, therefore, of a subsidence of the 
land to the extent of at least fifty feet. A re-elevation to 
that extent would nearly restore the island of greater 
Bermuda. Beyond this, in a south-westward direction, several 
shallows have been detected, all being surrounded by great 
* Bice, W. N., “ Geology of Bermuda,” p. 9. 
t Jones, J. M., “Becent Observations in Bermudas,” p. 262. 
