98 LIVING LIGHTS. 



swallower seems to possess a rubber-like character, stretching 

 to enormous dimensions, and often, when filled with gas, 

 carrying the glutinous light-bearer into the upper regions 

 of the ocean. 



Malacosteus niger, Ayres (Plate XXII.), is a rare fish, 

 from a depth of two-thirds of a mile ; though several speci- 

 mens have recently been taken by the United-States Fish- 

 Commission, and others by the " Talisman " off Morocco, in 

 forty-eight hundred feet of water. It is of small size, from 

 thirteen to fourteen centimeters in length, of a velvet-black 

 hue, and possesses two large luminous organs upon the head ; 

 one of which, according to M. Filhol, who observed the light 

 in the living fish, emits a golden, and the other a greenish 

 phosphorescence. We have here,' then, a fish that vies with 

 the Appendicularia, and other forms which we have seen 

 emitting light of more than one color. It is possible that 

 the rays of light from these spots project ahead of the fish, 

 in the manner shown in the accompanying figure, in which 

 the appearance of the light is of course conjectural ; but as 

 to the meaning of the different colors, are they a system of 

 signals cunningly devised by Nature to enable Malacosteus 

 to distinguish its kind in the profound depths of the ocean, 

 or are they merely lures of more than ordinary brilliancy ? 



In some fishes the luminous organs are extremely small, 

 almost invisible to the naked eye, and often spread over a 

 large extent of surface. Such an instance is seen in Uusto- 

 mias obscurus (Plate XIX.) and Neostoma. In the former, 

 an attenuated carnivorous fish of a jet-black color, we see 

 another example of remarkable feelers, or sense-organs. 



While these forms are probably free swimmers, there are 

 many others that are mud-dwellers, of most extraordinary 



