28 MARVELS OF FISH LIFE 



appears to sparkle with glittering light. Next moment 

 nothing is visible, and in a minute or two similar flashes 

 of light are to be observed in quite a different part of 

 the water. These flashes are caused by the young fish 

 simultaneously wheeling round with the precision of a 

 crack regiment. 



The fact that objects seen from below appear as 

 silhouettes against the sky, explains why many fish 

 on the look-out for food lie near the bottom. The spin- 

 ning bait, or the fly, fished just under the surface, will 

 bring up the salmon, the trout or the pike from the 

 bottom of the deepest hole. 



I well remember watching from the bridge above 

 the fishing of a pool on the Dee. A sunk fly was fished 

 past and in front of a salmon lying on a ledge of rock 

 without response, but when fished right above him he 

 twice came up to inspect it. I do not suggest that the 

 salmon could not see the deep fished fly, but that when 

 fished right above him it was much more obvious 

 against the sky, and so attracted his attention. I would 

 mention in passing that the most gaudy fly seen against 

 the surface of the water merely appears as a grey, 

 iridescent silhouette, and for this reason I do not think 

 the colour of the fly matters if the size be right for the 

 condition of the water and the fly be fished so as to 

 suggest life. 



Having so fully considered both concealing colora- 

 tion and reflection in the silvery dace, let us turn oui 

 attention to fish in which colour plays the greater part 



