ACCLIMATISATION. 77 



rctiict This was generally a fine fat grub taken 

 from a caddis case. The caddis is large and white, 

 and so can be seen to a considerable distance. 



As this sank in the water, there would be a general 

 rush at it, and the ensuing contention was amusing 

 in the extreme. First, one would catch it in his 

 mouth and shoot off; half-a-dozen others would 

 unite in chase, overtake the too fortunate one, seize 

 the grub from all sides, and tug desperately, their . 

 tails flying, their fins at work, and the whole mass 

 revolving like a wheel, the centre of which was the 

 caddis worm. 



It would be swallowed almost immediately, but 

 the mouth of the stickleback is much too small to 

 admit an entire caddis, and the skin of the grub is 

 too tough to be easily pierced or torn. Half-an-hour 

 often elapses before the great question is settled, and 

 the caddis eaten. 



The rapidity of the evolutions and the fierceness 

 of the struggle must be seen to be appreciated — and 

 it is a spectacle easily to be witnessed; wherever 

 there are sticklebacks, caddis worms are nearly cer- 

 tainly found, and it only needs to extract one of 

 these from its case and deposit it judiciously in the 

 water. 



The stickleback is a hardy little fish, and can 

 easily be kept in the aquarium, if plenty of room be 

 given to it. It has even been trained to five in sea- 

 water, by adding bay-salt to the water in which it 



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