232 THE FOUNDATIONS OF ZOOLOGY 



when the weather was favorable for outside collecting we found 

 siphonophores and pteropods, pelagic mollusks and Crustacea and 

 tunicates and all sorts of pelagic larvae 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, trans- 

 parent water stretches as far as 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 had 

 at last found a place where the pelagic fauna of mid-ocean could 

 be gathered 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 

 we dragged our surface nets through the sounds day after day 

 only to find them as clean as if they had been hung 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 without even a copepod or a zoea or 

 a pluteus. 



The absence of the floating larvae is most remarkable, for 

 the sounds swarm with bottom animals which give birth every 

 day to millions of swimming larvae. The mangrove swamps and 

 the rocky shores are fairly alive with crabs carrying eggs in all 

 stages of development, and the boat passes over great black 

 patches of sea-urchins crowded together by thousands. The num- 

 ber 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 well 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 ocean, but this is 

 a mistake, for the water is perfectly fit for supporting the most 

 delicate and sensitive animals, and those which we caught out- 

 side lived in the house in water from the sounds better than in 

 any other place where I ever tried to keep them, for instead 

 of being injurious, the pure water of coral sounds is peculiarly 

 favorable for use in aquaria for surface animals. 



