26 The Study of Animal Life parti 



filial debts to mother earth. We see life rising like a mist 

 in the sea, lowly creatures living in shells that are like 

 mosques of lime and flint, dying in due season, and sinking 

 gently to find a grave in the ooze. We see the submarine 

 volcano top, which did not reach the surface of the ocean, 

 slowly raised by the rainfall of countless small shells. Inch 

 by inch for myriads of years, the snow-drift of dead shells 

 fonns a patient preparation for the coral island. The 

 tiniest, hardly bigger than the wind-blown dust, form when 

 added together the strongest foundation in the world. The 

 vast whale skeleton falls, but melts away till only the ear- 

 bones are left. Of the ruthless gristly shark nothing stays 

 but teeth. The sea-butterflies (Pteropods), with their frail 

 shells, are mightier than these, and perhaps the microscopic 

 atomies are strongest of all. The pile slowly rises, and the 

 exquisite fragments are cemented into a stable foundation 

 for the future city of corals. 



At length, when the height at which they can live is 

 reached, coral germs moor themselves to the sides of the 

 raised mound, and begin a new life on the shoulders of death. 

 They spread in brightly coloured festoons, and have often 

 been likened to flowers. The waste salts of their living 

 perhaps unite with the gypsum of the sea-water, at any rate 

 in some way the originally soft young corals acquire strong 

 shells of carbonate of lime. Sluggish creatures they, living 

 in calcareous castles of indolence ! In silence they spread, 

 and crowd and smother one another in a struggle for stand- 

 ing-room. The dead forms, partly dissolved and cemented, 

 become a broad and solid base for higher and higher growth. 

 At a certain height the action of the breakers begins, great 

 severed masses are piled up or roll down the sloping sides. 

 Clear daylight at last is reached, the mound rises above the 

 water. The foundations are ever broadened, as vigorously 

 out-growing masses succumb to the brunt of the waves and 

 tumble downwards. Within the surface -circle weathering 

 makes a soil, and birds resting there with weary wings, or 

 perhaps dying, leave many seeds of plants — the begin- 

 nings of another life. The waves cast up forms of 

 dormant life which have floated from afar, and a ter- 



