212 LECTURE XII. 



in long arms, which at last unite in a circle, 

 within which they include a portion of calm, un- 

 troubled sea. On the opposite or windward side, 

 .the waves continually throw up fragments of 

 corals, which, accumulating by degrees, form a 

 mound against the billows; and on that part 

 the sea is rendered gradually shallower; while, 

 on the other side, immediately under the arms 

 raised by the Zoophytes, the sea is of an astonish- 

 ing depth; and not unfrequently, a part of the 

 work remains open far the. ingress and egress of 

 the tide. In the coral banks themselves, sand is 

 collected by the waves, affording soil and ali- 

 ment for the seeds of shore plants brought thither 

 by the sea; and these plants at length perish- 

 ing, gradually create and accumulate a vegetable 

 mould. If by chance a Cosoa-Nut be carried by 

 the sea to these spots, it germinates, and grows 

 into a tall tree, bearing, and disseminating many 

 nuts, some of which again germinating, soon form 

 a palm-grove, affording shade to birds and other 

 animals, and supplying navigators, driven to the 

 place by stress of weather, with a grateful food 

 and liquor. The bay included within the arms of 

 the Zoophytes is a receptacle for those fishes 



