THE GREAT DEEPS 129 



large luminous plates just under its eyes. One 

 of these gives off red light and the other 

 green, and from the arrangement of the mus- 

 cles connected with them, it is thought that 

 the fish has control over them, and can turn 

 on its lamps at will, to warn off its enemies 

 or to aid it in the search for its prey! 



" Very strange indeed would be the appear- 

 ance of these animals if we could see them in 

 the deep! In the absolute darkness of the 

 abyss they would appear as ghostly, silver- 

 blue shapes, glimmering like an electric lamp 

 through dense fog on a dark, moonless night. 

 Of all the characters of deep-sea fishes this 

 almost universal phosphorescence is the 

 strangest." 



Another puzzle may be found in the fact 

 that many deep-sea animals are brightly col- 

 oured. Bright red is common, for instance, 

 in crustaceans, star-fishes, and sea-anemones. 

 There is very little in the way of pattern, but 

 there is not a little colour. What can be the 

 meaning of colour in a world of darkness? It 

 is highly probable that the colours as such 

 have no significance in the life of these deep- 

 sea animals, that they are simply the useless 

 by-products of some of the fundamental proc- 



