NATURAL SELECTION, AND THE ANTIQUITY OF LIFE 231 



is most astounding, and it testifies most vividly and forcibly to 

 the wealth of life on the old sea-floor. 



No description can convey any adequate conception of the 

 boundless luxuriance of a coral island, but nothing else gives such 

 a vivid picture of the capacity of the sea-floor for supporting life. 

 Marine plants are not abundant on coral islands, and the animals 

 depend either directly or indirectly upon the pelagic food supply, 

 so that their life is the same in this respect as that of animals in 

 the deep sea far from land. 



The abundant life is not restricted to the growing edge of the 

 reef, and the inner lagoons are often like crowded aquaria. At 

 Nassau my party of eight persons found so much to study on a 

 little reef in a lagoon close to our laboratory, that we discovered 

 novelties every day for four months, and our explorations seldom 

 carried us beyond this little tract of bottom. Every inch of the 

 bottom was carpeted with living animals, while others were darting 

 about among the corals and gorgonias in all directions ; but this 

 was not all, for the solid rock was honeycombed everywhere by 

 tubes and burrows, and when broken to pieces with a hammer 

 each mass of coral gave us specimens of nearly every great group 

 in the animal kingdom. Fishes, Crustacea, annelids, mollusca, 

 echinoderms, hydroids, and sponges could be picked out of the 

 fragments, and the abundance of life inside the solid rock was 

 most wonderful. 



The absence of pelagic life in the landlocked water of coral 

 islands is as impressive and noteworthy as the luxuriance of life 

 upon and near the bottom. 



On my first visit to the Bahama Islands I was sadly disap- 

 pointed by the absence of pelagic animals where all the condi- 

 tions seemed to be peculiarly favorable. 



The deep ocean is so near that, as one cruises through the 

 inner sounds past the openings between the islets which form 

 the outer barrier, the deep blue water of mid-ocean is seen to 

 meet the white sand of the beach, and soundings show that tne 

 outer edge is a precipice as high as the side of Chimborazo and 

 much steeper. 



Nowhere else in the world is the pure water of the deep sea 

 found nearer land or more free from sediment, and on the days 



