CHOICE OF PATTERN iii 



vessel of water. The stomach is then cut longi- 

 tudinally down to the sphincter muscle, the contents 

 being turned out into a vessel of water, separated and 

 examined. If it is desired to keep and preserve 

 the contents of the trout's stomach, a small quantity 

 of washing soda should be added to the water so as 

 to neutralize the acid of the digestive fluid. If this 

 is neglected the process of digestion will continue 

 for a considerable time after death. 



The conglomeration of food in the water if gently 

 stirred will separate by gravity into two portions. 

 The portion that sinks to the bottom is food taken 

 by the trout on the bed of the river, and the portion 

 which floats consists of winged insects and nymphs 

 or pupae just on the point of emerging in the winged 

 state. The floating portion of the contents of the 

 trout's stomach is the only part which will interest 

 the fisherman when trying to decide on the pattern 

 of floating fly he should next try. 



The angler must not be surprised at the small quan- 

 tity of these floating insects, nor at the great variety 

 of genera and species represented. He may find quite 

 a number of ing le specimens of small beetles. Aphis 

 or green fly, Corixcs, a genus of water-bug, and many 

 others. He may also find some number of examples 

 of the duns, spinners, caddis-flies or smuts on which 

 the fish has been feeding, some winged and some, as 

 said before, just emerging from the nymphal or pupal 

 envelope. 



An examination of the large mass of food, which is 



