52 BROOK AND RIVER TROUTING 



of the day justified the surmise, that the fish under 

 the willows were feeding on such insects as hovered 

 above them, every now and then to touch the water, 

 while those out in mid-stream had no Silverhorns 

 available and so confined their attention to the spent 

 spinners, smuts and other flies, which were brought to 

 them by the current. 



If the solution of the problem that presented itself 

 on that first evening be correct, then the killing power 

 of a fly is often dependent on its being fished with 

 due regard to the haunts of the natural insect it is 

 supposed to imitate. WTiat a field is here for investi- 

 gation, and yet the matter is one upon which no hard 

 and fast rules can be made. Prevailing conditions 

 must be studied carefully. A cross-wind might obviously 

 entirely alter the local conditions, and one would not 

 look in such circumstances for flies in their usual haunts. 

 On windy days the observant angler would probably 

 find that the menu of the fish on the side from which 

 the wind was blowing would include many Diptera or 

 other land-bred insects, while the fish on the lee shore, 

 would most likely be feeding principally on such 

 insects of aquatic origin as happened to be hatching 

 out at the time. 



The foregoing merely serves to illustrate a few of the 

 many considerations involved in this absorbing sport ; 

 and in following up these problems many side issues 

 of equal importance will be opened up. 



