2 86 Dwellers of the Sea and Shore 



dred and seventy-five feet, and never do they live in 

 water the temperature of which is less than 68° Fahr. 

 In the tropics their great reefs extend for miles and 

 assume countless curious shapes, sometimes spreading 

 out like a fan, or branching in every direction, forming 

 figures and heads and limbs. This is characteristic of 

 the Tortugas Keys off the coast of Florida, but among 

 the coral reefs of the Pacific they form great circles, or 

 rings, called atolls. Many reefs are exposed and flour- 

 ish with vegetation, and the charm, the beauty, the 

 loveliness of these verdant isles can be realized only by 

 those who have passed them at sea. 



It is a curious fact that although corals have been 

 familiar objects since very ancient times, their animal 

 nature was not known until the eighteenth century. 

 The discovery was made by an amateur naturalist who 

 had succeeded in keeping some specimens of red coral 

 alive in a tank. His discovery, however, was rejected 

 by the professional men of science, and it was not until 

 nearly twenty-five years later that they were compelled 

 to recognize the truth of his claims. 



The coral animal is a coelenterate, a polyp. It re- 

 sembles an anemone with the difference that it has the 

 faculty of taking lime, probably from the water or from 

 the food it eats, and secreting it in the chambers of its 

 body, where it, the lime, forms partitions or cells, as 

 the case may be. Although they live in colonies, unlike 

 hydroids, each coral polyp is a complete individual in 

 itself, having no physical connection with its neighbors 

 other than the dead skeletal remains on which thev 

 make their home. The home of each individual is 

 called the coralUte, and a group of these corallites, such 



