THE THREE-SPINED STICKLEBACK. 285 



Description Enemies to other fish. 



in many of our rivers, particularly in those of 

 Lincolnshire. They have three sharp spines on 

 their back, according to their name, which are 

 their instruments both of offence and defence, 

 and are always erected on the least appearance 

 of danger, or whenever they are about to attack 

 other fish, The body near the tail is somewhat 

 square, and the sides are covered with transverse 

 bony plates. Their usual colors are olive green 

 above, and white on the under parts; but in 

 some individuals the lower jaw and the belly are 

 of a bright crimson. These fish likewise abound 

 on the Prussian coast near Dantzick, where they 

 are used for making oil, but more especially for 

 feeding ducks and fattening swine. 



Notwithstanding the smallness of their size, 

 they are, by feeding with great voracity on the 

 fry and spawn of other fish, greatly detrimental 

 to the increase of almost all the specie? imiong 

 which they inhabit. Mr. Arderon, of Norwich, 

 informs us in the Phil. Trans, that one uaicli he 

 had in a glass devoured in five hours no fewer 

 than seventy-four young dace, each about an 

 inch and a half long, and of the thick JK-SS of a 

 horse-hair, and would have done the same every 

 day, had they been given to it. Tiie fi^h was 

 put by Mr. Arderon into a glass jar of water, 

 with some sand at the bottom, for the purpose 

 of trying some experiments on it, as weli as fbr 

 the sake of ascertaining its manners, as far as 

 possible, in a confine^ state. For a few days it 



