y8 Fish Stories 



vegetation, and it is doubtless inhabited by a few ^nen who 

 dry the cocoanuts for copra, and gather in the lagoons, for 

 the Chinese trade, the black sea-cucumber, which sells as 

 beche de mer. These atolls, of which there are hundreds in 

 the South Pacific, are considered, rightly we think, to be a 

 product of the slow subsidence of this part of the sea. The 

 other islands of this region are all volcanic, high, sharp and 

 made of lava. Around each one, at a little distance from 

 the shore, is a barrier reef, built up of broken corals, a 

 shallow channel separating it from the island. On the out- 

 side of the reef are the living corals in great multitudes and 

 variety, each with its myriad small polyps, individually like 

 the sea anemones of farther north, but each one secreting 

 carbonate of lime in the cross partitions of its body. Most 

 of these are less than an inch across, some very much less. 

 But there are certain corals made by a single large polyp, 

 which may be a foot in diameter. 



The reef corals grow only in shallow and very salt water. 

 Wherever a river flows in, there is a break in the coral reef. 



If we imagine the volcanic island to sink slowly, the reef 

 would slowly rise to correspond. If this goes on long 

 enough, the island will vanish, leaving no trace, or only a 

 rock or prominence in the center of the lagoon. In this 

 fashion, as Darwin has pointed out, and in no other way of 

 which I can conceive, Mary Atoll was formed, and in the 

 same fashion as Mary are built all the rest of the Phoenix 

 group, and all the rest of the cosmic asteroids marked on 

 the map as Gilbert, Marshall, Ellice Islands and the rest. 



All these lagoons swarm with fishes little and big, colored 

 like a dozen rainbows, with suggestions from the Chinese, 

 Spanish and other gorgeous flags. Outside the reef they 

 are even more abundant, from the little green gobies less 

 than an inch long that creep about within the corals, or the 

 pearl fishes that hide in the stomachs of the heche de mer, 

 up to the biggest of sharks, and it is the sharks we have now 

 under discussion. 



