SHALLOW- WATER FAUNA OF THE TROPICS. 63 



is with difficulty kept to any particular point. 

 The feature which is perhaps the most striking 

 is, however, the wonderful variety in the 

 colours of the animals and of the character 

 of their markings. 



If we consider the Fishes alone, we find 

 some of them have broad yellow bands running 

 diagonally across their bodies, others have thin 

 longitudinal stripes of blue and yellow, some 

 have a uniform bright-red colour, and others 

 again have their red skins speckled with blue 

 spots. It would take more than a whole chapter 

 of this book to describe even the principal varie- 

 ties of pattern found on one such Coral-reef, but 

 the main fact that has to be related is that where 

 the reefs are built by brightly coloured Polyps, 

 there we find these curiously marked Fishes. 

 There can be little doubt that the marking and 

 colouring does give a certain amount of protec- 

 tion to them. Numerous individual cases have 

 been mentioned of Fishes which resemble some 

 particular Sea-weed or Coral; but this general 

 statement is the important one, that on a parti- 

 coloured background the striped and speckled 

 Fish are less conspicuous than those that are 

 modestly attired. 



The Fishes of the reefs, however, have other 

 means of protection than that afforded by their 

 colours. The Trigger-fish and Coffer-fish, for 

 instance, have a body encased in closely fitting 

 hard, thick scales, so that they might almost be 

 called "armour-plated fish"; and the Globe-fish 

 bristle all over with long and extremely sharp 

 spines. In the Trigger-fish there is a curious 



