13.-THE ORIGIN OF THE FOOD OF MARINE ANIMALS. 



BY W. K. BROOKS, 



Professor of Zoology in the Johns Hopkins University . 



Iii a picture of the land, the mind calls up a vast expanse of verdure, broken only 

 by water, and stretching through forest and meadow from high up on the mountains, 

 over hills aud valleys and plains, down to the sea. 



Our picture of the ocean is an empty waste, stretching on and on, with no break 

 in the monotony except, at long intervals, a floating tuft of sargassum or a flying- 

 fish or a wandering sea bird, aud we never think of the ocean as the home of vegetable 

 life. It contains plant-like animals, " zoophytes," in abundance, but while they resemble 

 plants or flowers in form and color and in their mode of growth, they are true animals 

 and not plants. 



At Nassau, in the Bahama Islands, the visitor is taken in a small boat, with 

 windows of plate glass set in the bottom, to visit the " sea gardens" at the inner end 

 of a channel through which the pure water from the open sea flows between two 

 coral islands into the lagoon. Here the true reef corals grow in quiet water where 

 they may be visited and examined. 



The bottom of the boat is below the surface ripples and reflections. When illumi- 

 nated by the vertical suu of the tropics and by the light which is reflected back from 

 the white bottom the pure, transparent ocean water is as clear as air, and the smallest 

 object, 40 or 50 feet down, is seen distinctly. 



As the boat glides over the great mushroom- shaped coral domes which arch up 

 from the depths, the dark grottoes between them and the caves under their over- 

 hanging tops are lighted up by the suu far down among the flower animals or 

 anthozoa and the animal plants or zoophytes, which are seen through the waving 

 thickets of brown and purple sea fans and sea feathers as they toss before the swell 

 from the ocean. 



There are miles of these " sea gardens " in the lagoons of the Bahamas, and it has 

 been my good fortune to spend many months studying their wonders; but no descrip- 

 tion can couvey any conception of their beauty and luxuriance, and I never spent a 

 day among the reefs without longing, at every turn, for the skill to copy with a brush 

 the new beauties which never ceased to present themselves. 



The general effect is very garden-like, and the beautiful fishes of black and golden 

 yellow and iridescent cobalt bine hover like birds among the thickets of yellow and 

 lilac gorgonias. The parrot fishes (Diodon and Ballistes) seem to be cropping the 

 plants like rabbits, but more careful examination shows that they are biting off the 

 tips of the gorgonias aud branching madrepores or hunting for the small Crustacea 



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