372 THE ORIGIN OF THE OLDEST FOSSILS. 



The deep ocean is so near that, as oBeciuises 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 the outer edge is a precipice as high 

 as the side of Chimborazo aiul 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 when the 

 weather was favorable for ontside collecting we found siphonoi^hores 

 and pteropods, pelagic mollusks and Crustacea and tunicates and all 

 sorts of pelagic larv;e in great abundance in the open water just outside 

 the inlets. 



Inside the barrier the water was always calm, and day after day it 

 was as smooth as the surface of an inland lake. When I first entered 

 one of these beautiful sounds, where the calm, transparent water 

 stretches as far the eye can reach, while new beauties of islets and 

 winding channels open before one as those which are passed fade away 

 on the horizon, I felt sure that I liad at last ibund a place where the 

 pelagic fauna of mid-ocean could be gatliered at our door and studied on 

 shore. The water proved to be not only as pure as air but almost as 

 empty. At high water we sometimes captured a few pelagic animals 

 near the inlets, but Me dragged our surface nets through the sounds day 

 after day only to find them as clean as if they had been hung in the 

 Avind to dry. The water in which Ave washed them usually remained as 

 l^ure and empty as if it had been filtered, and we often returned from 

 our touring expeditions without even a copepod or a zoea or a pluteus. 



The absence of the floating larvie is most remarkable, for the sounds 

 swarm with bottom animals which give birth every day to millions of 

 swimming larva'. The mangrove swamps and the rocky shoies are 

 fairly alive with crabs carrying eggs at all stages of development, and 

 the boat passes over great black i)atches of sea-urchins crowded 

 together by thousands. The number of animals engaged in laying 

 their eggs or hatching their young is infinite, yet we rarely captured 

 any larvae in the tow net, and most of these we did find were Avell 

 advanced and nearly through their larval life. 



It is often said that the water of coral sounds is too full of lime to 

 be inhabited by the animals of the open o(;ean, but this is a mistake, 

 for the Avater is perfectly fit for supporting the most delicate and sensi- 

 tive animals, and those Avhich we caught outside lived in the house in 

 water from the sounds better than in any other place Avhere I ever tried 

 to keep them, and instead of being injurnms the pure water of coral 

 sounds is peculiarly favorable for use in aquaria for surface animals. 



The scarcity of fioating organisms can have only one explanation. 

 They are eaten up, and comj)etition for food is so fierce that nearly 

 e\"ery organism which is swept in by the tide and nearly CA^ery larva 

 which is born in the sounds is snatched by the tentacles around some 

 hungry mouth. 



