24 ANIMAL LIFE UNDER WATER 



come up and look at it or some other pattern as 

 long as you like to continue this form of exer- 

 cise. But drop your fly to one side ; the trout 

 does a half-turn and swims towards it. You are 

 now no longer immediately behind the trout, 

 and you come into that portion of the arc of 

 the " window " which is visible to the trout ; he 

 sees your distorted features above him, and is 

 off like a dart. 



