CORAL ISLANDS I THEIR FORMATION. 223 



is carried thither; seeds are blown to it by the 

 wind; and gradually a few green blades arise. 

 From this little beginning it is easy to conceive 

 the process by which at last a nourishing island 

 springs up. At the same time, it is not easy to 

 see how such islands could ever be formed on the 

 supposition that the submarine rocks on which they 

 were founded were perpetually subsiding. 



But be that as it may, we have no difficulty in 

 understanding the fact that the coral insect does 

 build those islands. It possesses the power of 

 secreting the lime held in solution by sea water, 

 and depositing the same on the rocks below the 

 waves. The coral rock is the edifice of the coralline. 

 The insect itself is a soft and 

 very minute worm, which, 

 when washed by the waves, 

 thrusts its head out of its tiny 

 little door, and spreading I 

 abroad its numerous feelers, 

 so that it resembles a beauti- 

 ful little star, moves these 

 about as if enjoying itself 

 though, doubtless, it is actu- CORAL INSECT - 

 ally engaged in the process of manufacturing its 

 little atom of coral rock. 



It is extremely interesting to think of the im- 

 mense power of union thus exhibited. Singly, 

 those little creatures could not produce a sufficient 

 result to attract the attention of any creature save 



