82 BRITISH FRESH-WATER FISHES 



put on for nothing. The courtship of fishes — of those at least 

 with which we are most familiar in this country — is usually 

 a cold-blooded unromantic affair. Not so the stickleback's. 

 Early in the year he prepares a suitable place for his 

 establishment by clearing the neighbourhood of all 

 possible rivals. The weaker go to the wall ; at least, they are 

 compelled to decamp, and passengers have to prepare for battle 

 at short notice. The challenge is devoid of formality ; the lord 

 in possession dashes upon the stranger without any warning 

 and attacks him tooth and nail — that is, with nimble mouth and 

 trenchant spine. Peradventure the first owner of the coveted 

 nook is not able to hold his own, for a chance thrust of the 

 errant knight's spear may find a joint in the harness even of 

 a larger and more powerful fish. Which ever wins, the meed 

 of victory is soon apparent. The vanquished combatant fades 

 into ashen grey, and slinks away, perhaps to die of his wounds ; 

 but the victor, beginning to glow with brighter hues and to 

 shine with clearer lustre, seeks the legitimate reward of valour 

 in the favours of the fair sex. Many naturalists have described 

 the strange and fascinating little drama which ensues, and which 

 may be witnessed, it is said, by anybody who will be at the 

 pains to keep sticklebacks in a suitable aquarium. The 

 victorious male sets about constructing a nest. First he forms 

 a depression in the sand by rolling his prickly body about 

 therein ; then he collects delicate vegetable fibres, such as 

 stems of water-weeds or grass, rootlets, and so on, lays them 

 longitudinally in the hollow, and secures them in position by 

 the secretion of mucus from his skin. Next he begins to build 

 walls of similar materials, leaving an open space as a front 

 door, and finally adds a roof. The whole structure is described 

 as about one inch in diameter. 



By this time the stickleback has attained his utmost degree of 

 brilliancy, and swims abroad to seek a bride. There are plenty 

 of more or less eligible and attractive maidens in the neighbour- 

 hood, for these little fish, notwithstanding the inveterate pugnacity 



