186 ANIMAL COLOEATION". 



feet across the disc when fully expanded. In the interior — 

 in the gastral cavity, that is to say— of this gigantic polyp 

 there is often a small fish belonging to the species AmpJdprion. 

 percula. 



When this fact was first observed it was thought that the 

 occurrence of the fish in the interior of the polyp was simply 

 a preliminary to its being digested by the latter. Mr. Kent, 

 however, found that the fish when dislodged by a stick 

 invariably returned to its singular dwelling-place, apparently 

 oblivious of the danger likely to result from a contact with 

 the stinging arms of the anemone. The fish is very brightly 

 coloured, being " of a brilliant vermilion hue, with three broad 

 white crossbands." Mr. Kent suggests — and the idea is very 

 plausible — that benefits are mutually conferred by this habit. 

 The fish, being conspicuous, is liable to attacks, which it 

 escapes by a rapid retreat into the sea anemone ; its enemies 

 in hot pursuit blunder against the outspread tentacles of the' 

 anemone, and are at once narcotised by the " thread cells,"' 

 shot out in innumerable showers from the tentacles, and 

 afterwards drawn into the stomach of the anemone and 

 digested. 



The plausibility of this very interesting suggestion is in- 

 creased by the fact that there is a similar association between 

 an allied species of anemone and a prawn. Singularly 

 enough, the prawn has a plan of coloration similar to that 

 of the fish. The reason for this is not at all apparent, and 

 Mr. Kent is nnable to offer any explanation of the similarity 

 of the colours and coloration of the two animals. He 

 believes, however, that in both instances the active animals 

 play the part of a lure to attract prey within reach of the 

 motionless anemone, and in return get protection. 



This suggestion is of course quite at variance with any 



