THE THREE-SPINED STICKLEBACK. I5I 



into the water to it. It would suffer no other fish 

 to live in the same jar, attacking whatever were 

 put in, though ten times its own size. One day, bv 

 way of diversion, a small fish was put to it. The 

 Prickleback immediately assaulted and put it to 

 flight, tearing off part of its tail in the conflict; and 

 had they not been then separated, he would un- 

 doubtedly have killed it*. 



Small as these animals are, they are sometimes so 

 numerous as to be obliged to colonize, and leave 

 their native places in search of new habitations. 

 Once in every seven or eight years they appear in 

 the river Welland, near Spalding in Lincolnshire, in 

 such amazing shoals, as, during their progress up 

 the stream, to appear in a vast body occupying the 

 whole width of the river. These are supposed to 

 be the overplus of multitudes collected in some or 

 the fens. When this happens they are taken as 

 manure for the land ; and an idea may be formed 

 of their numbers, from the circumstance that a man j 

 employed by a farmer to catch them, got, for some 

 time, four shillings a day by selling them at a half- 

 penny a bushel f , 



The great exertions they use, in getting from one 

 place to another, where obstacles intervene, are 

 very extraordinary ; for, though the largest among 

 them is seldom known to be more than two inches 

 in length, they have been seen to spring a foot and a 



* Phil. Trnn. vol. xliv. p. 124. 

 + Pen. Brit. Zool. iii. 261. 



L 4 



