GREA T BRITAIN. 3 1 



certain kinds of baits, but how they did so is difficult to 

 determine. 



Voluntary and involuntary sounds, due to emotions, are 

 emitted in different manners by many fishes, and in some 

 rare instances solely at certain seasons. Very dissimilar 

 organs may originate somewhat similar sounds, while 

 apparently identical ones may not always be expressive 

 of the same feeling. Some sounds are perceived on fish 

 being removed from hooks and thrown into a basket. 

 These may be temporary, mostly involuntary, and often 

 convulsive : or their production may be due to unusual 

 movements of the jaws, opercles, or other bony elements ; 

 or else induced in thick-lipped forms when compelled to 

 suddenly open their mouths. There are likewise voluntary 

 sounds, such as constant ones, always produced by the 

 same organ, and which are evidently intentional, some- 

 times even being characteristic of a species ; as a harsh 

 grating sound as of stridulation, caused by the friction of 

 the dental organs, or some bones, as the pharyngeals, which 

 guard the entrance into the gullet. Then there are blowing 

 sounds, as noticed in the carp tribe and among the siluroids, 

 which have been attributed to the expulsion of gas from 

 the air-bladder ; musical sounds caused by the contraction 

 of muscles, which are contiguous to the air-bladder, so that 

 the latter acts as a kind of sounding-board ; and purring 

 sounds as made by the maigre. 



Many instances are on record of fishes showing affection 

 one to another, and pining away when separated, but 

 recovering on being again brought together. So also they 

 show unmistakeable proofs of anger, as may be seen in 

 sticklebacks (G aster ostens), which fight for the possession 

 of some denied corner of an aquarium, when one being 

 defeated the conqueror becomes more gorgeous in his hues. 



