CH. III.] HOW THEY ARE PRODUCED. 49 



Carp's habit, while "priming" along the edges of 

 ponds at night, of sucking in from the interstices 

 amongst the bricks, &c., any insects which may be 

 lurking there, and which he could not otherwise 

 get within reach of his mouth, and afterwards 

 rejecting any substances which may not suit him, 

 all "between wind and water," as a sailor would 

 say. The fact that these noises are louder, more 

 prolonged, and more frequent in a pond faced with 

 brickwork, than in one the sides of which slope off 

 gradually and present a comparatively even sur- 

 face, seems to lead to this conclusion. When 

 feeding Carp with bread, you may often see this 

 power of suction exercised by one as he rises 

 almost perpendicularly under a piece floating on 

 the surface, and draws it down in a little vortex 

 to his scarcely visible mouth, which, by the way, 

 is thus enabled to take in much larger morsels 

 than it otherwise could. A few minutes' close 

 inspection of gold fish in an aquarium will shew 

 the same process of indraught and expulsion con- 

 tinually in operation. 



I have no doubt that, owing to this habit of the 

 Carp in thus priming along the sides of ponds at 

 night, a night-line set with the bait hung on the 

 surface of the water, close to the edge, would be a 



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