CORAL REEFS OF TORRES STRAITS 217 



wins in this strife for place in the region 1,000 feet from shore. It is, 

 however, very sensitive to high temperature, and the warm shallows 

 close to shore are fatal to it so it can not survive within 550 feet of the 

 beach. Also, being very slender, it can not survive the rush of the 

 breakers and, thus it disappears about 1,670 feet out from shore where 

 the surges shatter its fragile stems. Delicate and sensitive to high tem- 

 perature, to silting, and to agitated water as it is, however, if condi- 

 tions be ideal for its existence, it thrives so well that all other corals, 

 even those that can live anywhere over the reef- flat, must give way to it. 

 The amount of food required to support the vast coral population of 

 this reef-flat must be very great, especially, as Dr. Vaughan discovered, 

 corals are strictly carnivorous and will not even attempt to capture 

 plants. The minute floating animal life of the ocean is therefore the 

 chief source of food for corals. Moreover, Dr. Vaughan showed that it 

 is possible at a glance to tell the difference between a fat-looking, well- 

 fed coral and the thin, drawn appearance of a starved one. The corals 

 of the southeast reef of Maer Island, however, all seem to be well fed, 

 and thus it appears that the question of food has little or nothing to 

 do with their struggle for existence. 



There are, however, no large heads upon this reef, only a vast array 

 of small ones. 



Now the Murray Islands are in a fortunate region which is never 

 visited by hurricanes, and thus the corals grow on for ages undisturbed 

 by severe storms. Along the entire southeast beach only two small coral 

 heads were found tossed ashore by the waves, a striking fact in contrast 

 with the great heaps of dead coral ten feet high, found strewn along 

 the shores of the Paumotos Islands where severe hurricanes occur. 



Pocillopora damicornis. The fragile specimen on the right grew in the calm 

 waters of the reef flat. The rigid one on the left grew in a tide pool among the 

 breakers. Murray Islands, Torres Straits. 



