38 THE DEPTHS OF THE SEA 



hunger. Many of the fishes have enormous jaws, the 

 angle of the mouth being situated at least one-third of 

 the body-length from the anterior end. The gape is 

 prodigious, and as the edge of the mouth ^is armed 

 with recurved teeth, food once entering has little 

 chance of escape. So large is the mouth that these 

 creatures can swallow other fish bulkier than them- 

 selves ; and certain eels have been brought to the 

 surface which have performed this feat, the prey 

 hanging from beneath them in a sac formed of the dis- 

 tended stomach and body-wall. It has been said of 

 the desert fauna that ' perhaps there never was a life 

 so nurtured in violence, so tutored in attack and de- 

 fence as this. The warfare is continuous from the 

 birth to the death.' The same words apply equally 

 to the depths of the ocean. There, perhaps, more 

 than anywhere else, is true the Frenchman's descrip- 

 tion of life as the conjugation of the verb ' I eat,' with 

 its terrible correlative, ' I am eaten.' 



Connected with the alimentary tract, though in 

 some fishes shut off from it, is the air-bladder, an 

 organ which contains air secreted from the blood, and 

 which, amongst other functions, serves to keep the 

 fish the right side up. The air can be reabsorbed, 

 and is no doubt, to some extent, controlled by mus- 

 cular effort ; but there are times when this air-bladder 

 is a source of danger to deep-sea fishes. When they 

 leave the depths for shallower water, where the 

 pressure is diminished, the air-bladder begins to ex- 

 pand ; and, should this expansion pass beyond the 

 control of the animal, the air-bladder will act as a 

 balloon, and the fish will continue to rise with a rate 

 of ascension which increases as the pressure lessens. 

 Eventually the fish reaches the surface in a state of 

 terrible distortion, with half its interior hanging out of 

 its mouth. Many such victims of levitation have been 

 picked up at sea, and from them we learnt something 



