172 JOHNS HOPKINS UNIVERSITY MOEPHOLOGICAL MONOGRAPHS. 



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

 as far as the eye can reach, and 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 had at last found a place where the pelagic 

 fauna of mid-ocean could be taken home alive and studied on shore. 



The water proved to be not only as pure as air, but also as empty. 

 At high water we sometimes captured a few pelagic animals near the 

 inlets, but we dragged our surface-nets through the sounds day after day 

 only to find them as clean as if they had been hung out in the wind to 

 dry. The water in which we washed them usually remained as pure 

 and empty as if it had been filtered, and we often returned from our 

 towing expeditions in the sounds without even a copepod or a zoea or a 

 pluteus. 



The absence of floating Iarva3 is most remarkable, for the sounds 

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

 swimming larvas. The mangrove swamps and the rocky shores are 

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

 the boat passes over great black patches of sea-urchins crowded together 

 by thousands, and the number of animals which are engaged in laying 

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

 any larvae in the tow-net, and most of those which we did find were old 

 and nearly through their larval life. 



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

 to be inhabited by the animals of the open ocean, but this is a mistake, 

 for the water is perfectly fitted for supporting the most delicate and 

 sensitive animals, and we had no difficulty in keeping alive, in water 

 taken from the sounds, the surface animals which we caught outside. 

 Even trachomedusas and doliolums, which are extremely sensitive to 

 impurities in the water, could be kept alive in the house very much 

 better than in any other place where I have ever tried to keep them, 

 and instead of being injurious, the pure water of the sounds is peculiarly 

 favorable for use in aquaria for surface animals. 



The scarcity of floating organisms can have only one explanation. 

 They are eaten up, and competition for food is so fierce that nearly every 

 organism which is swept in by the tide, and nearly every larva which is 

 born in the sounds, is snatched by the tentacles around some hungry 

 mouth. 



Nothing could illustrate the fierceness of the struggle for food 

 among the animals on a crowded sea-bottom more vividly than the 



