SUBAQUEOUS HAPPENINGS IN NATURE 9 



the water, giving the trout a chance while in 

 transit. Thus the trout may well be familiar 

 with winged insects under water. Even if he 

 were not, it may be doubted whether he is suffi- 

 ciently intelligent to reject a thing which he 

 fancies he has found good to eat on the surface 

 merely because it happens to be below. Indeed, 

 experience so conclusively proves that trout will 

 take the winged fly under water that those who 

 repudiate both these propositions are upon the 

 horns of a dilemma. Many hackled ffies are more 

 or less — and generally less — careful imitations of 

 nymphs or larvae. But of these more anon. 



OF THE STAGES IN A RISE OF DUNS. 



It has often been the subject of admiring com- 

 ment that, before ever the angler can see a single 

 fly in air or upon water, the trout will have lined 

 up under the banks, and settled at the tails of weed- 

 beds, and have begun to take toll of insect life ; 

 and many have commented on the startling una- 

 nimity with which trout begin to feed all at once 

 all over a river or length. Some seem to suppose 

 that, with a quick appreciation of values of tem- 

 perature, atmosphere, barometric pressure, and 

 what not, the trout discern when the ffies will rise, 

 and are there in readiness. Is it necessary to sup- 

 pose anything far-fetched ? It has often seemed 

 to me that the swallows and martins can and do 

 detect in advance the preparations for a rise in the 



2 



