i8o MARVELS OF FISH LIFE 



weighing just under half a pound. Water ran through 

 this tank night and day, and the glass was shaded 

 from the sun except when it was removed two or 

 three times a day, so as to get the fish accustomed to 

 being suddenly surrounded by bright light. 



At the end of a week I put some minnows in the 

 tank ; but the perch would not take these and so they 

 were removed. The minnows were offered to the 

 perch every day during the next week with the same 

 result. At the end of a fortnight the perch took a 

 minnow, and after that he fed fairly freely. He then 

 became comparatively tame, and I obtained several 

 photographs, three of which are shown. 



My reason for removing the food unless the fish 

 took it was that the perch would have become accus- 

 tomed to wait until he was left alone before he fed, 

 and I should never have had an opportunity of obtain- 

 ing photographs illustrating many interesting attitudes 

 which are connected with the feeding of a fish. 



When a fish refuses to feed for a considerable time 

 I turn him free and start again with a fresh one, for fish 

 vary very much in temperament. One will be per- 

 fectly tame in a tank in a month or six weeks, whereas 

 another will never get accustomed to such surroundings, 

 and in consequence he does not feed, and will die of 

 starvation unless released. 



The photographs illustrating the nesting of the 

 sticklebacks were only obtained after three years' 

 work, for the fish, though they nested, would never 



