28 A NATURAL HISTORY OF THE SEAS 



ashore and denuded of its limey Polyp shells is often 

 mistaken for a shrub torn from the cliff or foreshore. 



Polyps which invest themselves with stony tenements 

 abound in most tropic seas but are by no means confined 

 to them. Several species come from deep water in northern 

 latitudes and one is tolerably common off our south- 

 western shores. The latter is known as the Devonshire Cup 

 Coral (Caryophyllia). Its white stony house stands about 

 half an inch high and the brilliant flower-like Polyp when 

 expanded towers above it, retreating with lightning speed, 

 however, at the slightest disturbance. 



Since the publication of Darwin's famous work much 

 literature has been devoted to the study of corals and coral 

 reefs, whilst the coral iself has been devoted to innumerable 

 uses from the earliest times. The famous Precious Coral 

 comes chiefly from the Mediterranean and from earliest 

 antiquity has been prized as an ornament, and an antidote 

 to poisons, as well as a general panacea. This coral 

 reproduces by eggs or buds, the male and female polyps 

 being segregated in separate colonies. The gathering of 

 the Precious Coral is effected by a crude drag made of 

 thick nets attached to two heavy beams joined in the form 

 of a cross. The coral being brought ashore is stripped 

 of its outer bark and subjected to an elaborate process of 

 polishing. 



Reef-building Coral forms the stable building material 

 in all the countries where it occurs. Reef Corals are 

 the result of the union of Polyps, each divided Polyp 

 raising around itself a wall of hard limey material. Since 

 the colonies grow from the bottom upwards, the pressure 

 exerted by later generations consolidates the vacated homes 



