38 



FOOD OF FISHES. 



blood- worms are an excellent bait, and it is no doubt 

 on account of their general resemblance in colour to 

 these., that most fish will eat earth-worms, which can- 

 not possibly be their natural food, since they can only 

 come into the water by rare accident. The same may 

 be said of the beetle grubs of the cockchafer and of the 

 dung beetle. 



, Blood-worm ; 6, the gnat (Chirononms plum&sis} which springs from 

 it, magnified. 



Shell Fish. 



In most rivers, lakes, and canals, no less than in the 

 sea, there are several species of shell fish, more particu- 

 larly those usually termed muscles, of which every 

 species of fish seems to be fond ; probably on account 

 of the difficulty of procuring them, for though the shell 

 must be opened when they feed, it is closed with the 



