THE TUFT CORAL 131 



PLATE XLIV 



THE TUFT CORAL (i) 



Nearly all the coral-building animals are found 

 in the tropical seas, for they can only live in water 

 which is quite warm all the year round. But 

 there are just a very few which are sometimes 

 found off our own shores, and one of these is 

 the Tuft Coral. It looks rather like a tree which 

 has just been " pollarded " by having all the small 

 branches taken away and all the big ones cut 

 quite short; and sometimes it weighs as much 

 as six or even seven pounds. 



People sometimes say that the curious sub- 

 stance which we call "coral" is made by "coral 

 insects." But the little animals which make it 

 are not related in any way to the true insects. 

 They are really tiny polyps, very much like those 

 of the sea finger ; and they suck up lime out of 

 the water, and build it up underneath and round 

 their own bodies, just as the madrepores do. 



If you were to place one of these tuft corals 

 in a vessel of clear sea- water, and to watch it care- 

 fully, you would soon see the little polyps poking 

 themselves out, and spreading their tiny fleshy 

 feelers, or "tentacles." The coral which they 

 make is pearly white in colour, with just a faint 

 tinge of rosy red, and the polyps themselves are 



