80 



THE SCIENCE OF DRY FLY FISHING. 



60 degrees behind each shoulder. In other words, that 

 any object situated in the 300 degrees of the forward part 

 of the horizontal circle surrounding it may be visible, while 



DIAGRAM 7. 



A B C D, horizontal plane of trout's vision. 



E T, trout. 



D A C B, horizontal zone of trout's sight. 



any object situated in the remaining 60 degrees of that 

 circle must be invisible as a general rule. Mr. Sheringham 

 reminded me the other day that trout can apparently see at 

 times directly behind themselves. I admit that trout do become 

 aware of a man's presence at times, when in the supposed 



