THE STICKLEBACK 85 



pulls the home to pieces, and the family assembles on the 

 ruins. In the larval form the young fry are provided with 

 natatory membranes extending the whole length of the body. 

 At the age of twelve days or so these are absorbed as the 

 fins and spines begin to appear, and shortly afterwards a 

 colony of perfect little fishes swims forth to take the chances 

 of this unequal world. 



It is a strange history, which any one may verify for him- 

 self. So entirely are the cares of the family concentrated in 

 the male that, should he be captured or otherwise come to 

 grief during his period of guardianship, the nest is torn to 

 pieces by other sticklebacks and the contents devoured. It 

 is supposed that in the manner described the male stickleback 

 usually constructs three nests, and rears as many broods of 

 from sixty to one hundred and twenty fry in the course of 

 a single season. 



In spite of its diminutive form, and, proportionately, still 

 more diminutive mouth, this stickleback destroys a prodigious 

 number of the young of other fish. GUnther records that a 

 single stickleback confined in an aquarium devoured, in five 

 hours' time, " seventy-four young dace, which were about a 

 quarter of an inch long, and of the thickness of a horsehair. 

 Two days after it swallowed sixty-two, and would probably 

 have eaten as many every day could they have been procured. 

 Nor have these restless little creatures any respect for larger 

 fish. Mr. Houghton tells of a small pike which he kept in 

 the same tank with some sticklebacks. The little wretches 

 were perpetually nibbling at the pike's tail fin, which is as 

 though a pack of school-children should amuse themselves 

 by twisting the tail of a tiger. Often the larger fish 

 would dash among his tormentors, and, seizing one of them, 

 try to swallow It. He never succeeded ; the spines were 

 too much even for jaws so well armed, and the malefactor 

 was speedily ejected. Day by day the luckless pike's tail 

 fin diminished in size, till Mr. Houghton, commiserating 



