160 CORALS AND CORAL ISLANDS. 



tion between the Friendly Islanders and the Feejees has long 

 been kept up by means of these large rudely-rigged sail-canoes. 



Instead of a rock-bound coast, harborless and thinly hab- 

 itable, like St. Helena, in Ihe tropics, and nearly all extra- 

 tropical islands, the shores of these reef-bound lands are bloom- 

 ing to the very edge, and wide plains are spread out with 

 bread fruit and other tropical productions. Harbors, safe for 

 scores of vessels, are also opened by the same means ; and 

 some islands number a dozen, when the unprotected shores 

 would hardly have afforded a single good anchorage. Jukes 

 remarks that the sea within the great Australian barrier is 

 "one great natural harbor : " and this harbor is as long as 

 from the extremity of Florida to Newfoundland. 



Coral-reefs are sometimes viewed as only traps to sur- 

 prise and wreck the unwary mariner ; but whoever has vis- 

 ited the dreary prison-house, St. Helena, will have some appre- 

 ciation of the benefits derived from the growing zoophytes. . 



But in addition to these general benefits, there are also 

 contributions from the larger reef regions to the commerce 

 of the world. Besides pearls, there is the biche de mar 

 (called also, beche de mer, sea-ginseng, and in China, tripang), 

 thousands of hundred- weight of which annually enter the 

 Chinese market from the reef-regions of the East Indies, Aus- 

 tralia, and the seas to the north, including the Feejee Archi- 

 pelago. This favorite material for Chinese dishes, either stews 

 or soups, etc., is dried holothuria — large slug-like animals, 

 called often sea slugs, and also sea cucumbers, from their form 

 in the contracted state. They are not slugs, but are most 

 nearly related to the echinus, though having a thick flexible 

 skin, while the echinus has for its exterior a firm shell, armed 

 about with spines. The largest are only nine or ten inches 

 long when contracted ; but they lengthen out sometimes to 



