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American Fisheries Society 



rainbow like fringe so that in this respect that part of 

 the fishes visual world differs from ours. The writer has 

 recently verified Von Aufsess' observations with the mir- 

 ror and has obtained views essentially like those shown 

 in figures 2 and 3. Objects within the angle 12° are visi- 

 ble at its upper limit, but become gradually less visible 

 as they are lowered, and disappear completely at about 

 the middle of this angle. All objects are fringed with 

 color, more red near the horizon, more blue higher up. 

 Objects within the angles IV and 96° are clearly seen 

 when the water is quite still, but are distorted and con- 

 fused upon the slightest movement of its surface. 



Fig. 3 



Figure 3 shows a view above and below water as it 

 appears to a fish, with the angles of figure I indicated 

 on the margin. In the views shown in figures 2 and 3 

 the fish would see all the branches and twigs of the trees 

 as well as all other objects bordered with a rainbow 

 fringe. 



Imagine then our dawn and twilight to be greatly 

 lengthened and our mid-day shortened. Imagine the 



