REVIEWS AND BOOK NOTICES. 679 
further, no barrier of land extended across from South America 
to the Canaries and Africa, dividing the South from the North 
Atlantic, but all was one great ocean. Such a barrier would not 
annul entirely the flow of the Gulf Stream ; yet the North Atlantic 
n ocean, that if left to itself its system of currents 
would be very feeble.” 
We would have liked if space allowed to reprint the whole of 
the section entitled ‘‘ The Oceanic Coral Island Subsidence.” We 
reproduce portions, however, for the most part in the author’s 
= own words. While he has shown that coral islands are records of 
_ slow changes of level in the ocean’s bottom, they are also records 
of the contour of the ocean bed, as they indicate submarine linear 
ranges of mountains ‘‘the whole over five thousand miles in 
length,” the whole area of subsidence being over six thousand 
miles in length, with a width equalling that of North America, thus 
forming an example of one of the “great secular movements of 
the earth’s crust.” The subsidence was in progress during the 
Glacial era, while the more northern continental lands, ‘* at least 
those of North America,” were being elevated, preparatory to, or 
during that era of ice: and this elevation of land northward “ may 
have been a balance to the downward oceanic movements that 
resulted in the formation of the Pacific atolls.” 
There was a similar subsidence in the West Indies. “The penin- 
sula of Florida, Cuba, and the Bahamas look, as they lie together, 
as if all were once part of a greater Florida, or southeastern pro- 
longation of the continent.” Professor Dana believes that a very 
large number of islands, more than has been supposed, lie buried 
in the ocean, and he cites the interesting example of the “lonely 
Bermuda atoll.” “Its solitary state is reason for suspecting that 
great changes have taken place about it; for it is not natural for 
islands to be alone.” r 
We quote the following paragraph, believing, that it is the key 
to many of the laws of geographical distribution of plants and 
Animals, as it opposes many crude theories of the existence of 
former continents and continental bridges which naturalists assume 
to account for the present distribution of life on opposite shores 
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‘While thus seeming to prove that all the great oceans have 
‘her buried lands, we are far from establishing that these lands 
Were oceanic continents. For as the author has elsewhere shown, 
