168 THREE-SPINED STICKLEBACK. 



of Providence, whilst the elegance and complexity of their 

 form, only require examination to excite admiration, and their 

 habits and instincts are so full of curiosity as to secure 

 attention when it has been directed towards them. 



Our Common Sticklebacks are inhabitants of both salt-water 

 and fresh, but they do not in preference frequent the open 

 sea, and a quiet union of the sea-water with the fresh appears 

 the most congenial with their nature, — as we may judge by 

 the abundance to be met with in such situations. In large 

 ponds of this description they increase to an enormous extent, 

 and may be seen traversing their daily range again and again, 

 in numerous companies, and hunting eagerly for food, which 

 appears to be formed of any of the smaller inhabitants of the 

 water they are able to swallow. Myriads of the half-developed 

 young of flying insects — the smaller creatures whose office it 

 is to keep down superfluous increase of vegetable life, but 

 which themselves might otherwise multiply in numbers too 

 great, so as to be among the evils themselves were destined 

 to abate, — and, we must add, the young of such fishes as are 

 then bursting into life: all of these contribute to the suste- 

 nance of these tribes of wandering plunderers, until at last 

 their numbers also have grown to be excessive. Birds feed 

 on them; but their formidable enemy is man, and Avith his 

 net they are swept to the bank in helpless heaps, to become 

 of some service to the people who have been at the trouble 

 to catch them. In some places they are employed for the 

 purpose of feeding ducks or pigs; and sometimes they are 

 drawn on shore in such heaps as to serve for manure, for 

 which purpose they are said to be of considerable value, a 

 fact not improbable, when, according to Lacepede, they are 

 known to aflbrd by pressure a good supply of oil, which we 

 suppose can only come from the liver. 



^In the Baltic, Professor Nilsson says that about the beginning 

 of November, before they retire to their winter quarters, they 

 assemble on the coasts of that sea in incredible shoals, and 

 are caught in boat-loads by fishermen. The only use made of 

 them is to boil them for the purpose of skimming the fluid for 

 the oil. A bushel of these fish yields about two gallons of oil. 

 The refuse is employed for manure. 



They breed generally in summer, and then it is that the most 



i 



