OF FISHES. 43 



There are circumstances, in which fishes are 

 buoyed to the surface, in spite of their utmost exer- 

 tions, by the rarifaction of the air within the sound. 

 On George's Bank, the fishermen not unfre- 

 quently take a cod, that comes to the top of 

 the water with a heavy lead, before it is possible 

 to coil the line, owing to the protrusion and buoy- 

 ancy of the bladder, through the mouth. 



PROTRUSION OF THE AIR BLADDER THROUGH THE MO0TH. 



During exceedingly warm weather, fishes in 

 shoal water sometimes die from the bursting of the 

 sound, or by the air forcing it through the mouth. 

 If they were, on the approach of this trouble, to 

 plunge into colder water, the air would be sud- 

 denly condensed, and they would escape; but, 

 unfortunately, they are apt to loiter in shoal coves, 

 for the worms and insects which the heat of the 

 sun brings into activity. Thus, in turn, they be- 

 come food for the very animals for which they 

 were searching. 



