CORAL AND CORAL REEFS 401 



towards the outside ; and that cup is formed of carbonate 

 of lime, only not stained red, as in the case of the red coral. 

 And all these cups are joined together into a common 

 branch, the result of which is the formation of a beautiful 

 coral tree. This is a great mass of madrepore, and in the 

 living state every one of the ends of these branches was 

 terminated by a beautiful little polype, like a sea anemone, 

 and all the skeleton was covered by a soft body which 

 united the polypes together. You must understand that 

 all this skeleton has been formed in the interior of the 

 body, to suit the branched body of the polype mass, and 

 that it is as much its skeleton as our own bones are our 

 skeleton. In this next coral the creature which has formed 

 the skeleton has divided itself as it grew, and consequently 

 has formed a great expansion ; but scattered all over this 

 surface there were polype bodies like those I previously 

 described. Again, when this great cup was alive, the whole 

 surface was covered with a beautiful body upon which 

 were set innumerable small polype flowers, if we may so 

 call them, often brilliantly coloured ; and the whole cup 

 was built up in the same fashion by the deposit of carbonate 

 of lime in the interior of the combined polype body, formed 

 by budding and by fission in the way I described. You 

 will perceive that there is no necessary limit to this process. 

 There is no reason why we should not have coral three or 

 four times as big ; and there are certain creatures of this 

 kind that do fabricate very large masses, or half spheres 

 several feet in diameter. Thus the activity of these animals 

 in separating carbonate of lime from the sea and building 

 it up into definite shapes is very considerable indeed. 



Now I think I have said sufficient as much as I can 

 without taking you into technical details, of the general 

 nature of these creatures which form coral. The animals 

 which form coral are scattered over the seas of all countries 

 in the world. The red coral is comparatively limited, but 

 the polypes which form the white coral are widely scattered. 

 There are some of them which remain single, or which 

 give rise to only small accumulations ; and the skeletons 

 of these, as they die, accumulate upon the bottom of the 

 sea, but they do not come to much ; they are washed 

 about and do not adhere together, but become mixed up 

 with the mud of the sea. But there are certain parts of 

 the world in which the coral polypes which live and grow 

 are of a kind which remain, adhere together, and form 



