The Structure of Game Fishes 9 



The brain of the fish is very small, and the lat- 

 ter has limited intelligence. Its powers of smell 

 are fairly well developed, and the hearing is more 

 or less acute ; the organs of hearing being small 

 cavities on each side of the head, containing a 

 liquid in which float two ear-stones or otoliths. 

 In some fishes, as the California "groupers," the 

 stones are an inch in length, pearl tinted and 

 flinty, attractive objects in demand as " head- 

 stones " and " good luck stones." 



The fish is enveloped in scales, which in the 

 game fishes described overlap each other like 

 shingles. They grow out of the little pockets in 

 the skin and are moistened or lubricated by a 

 secretion or slime, always noticed in a fish, which 

 exudes beneath them, and particularly along the 

 median line, an undulating line extending from 

 the head to the base of the tail. The game fishes 

 mentioned in this volume all increase by deposit- 

 ing eggs or spawn, the eggs minute spherical 

 objects often forming enormous masses. The 

 caviare of commerce is the roe of the sturgeon. 

 The number of eggs is inconceivable. In the cod 

 it is estimated at five millions. This is a wise 

 provision of nature, as fishes feed upon their own 

 kind. Sardines, herrings, and many birds devour 



