56 THE WAY OF A TROUT WITH A FLY 



force of the current, he tends to drop back down- stream, as 

 his mouth comes up to meet the fly, with the body at times 

 almost perpendicular to the surface. Then, opening his 

 mouth, our fish by means of an expansion of his gills 

 induces a small current of water, carrying the fly in with 

 it. It is at this stage that he makes the only real effort, 

 beyond the initial alteration of the plane of his fins, in the 

 whole process. He has to turn down to regain his station, 

 and this requires a vigorous turn of the whole body in order 

 to overcome the upward thrust of the current, and to 

 convert what was an upward movement into a downward 

 one. It is this turn downwards, with its brisk curving 

 of the body and sharp thrust of the tail, that produces 

 that surface effect which, in the case of a fish feeding under 

 these conditions, is commonly known as " the rise." And 

 it follows that the faster the water the more vigorous that 

 turn must be, though a swirling water will disguise and 

 carry away its effect much more than will a smooth stream. 

 The structure of the vertebral column of the trout 

 does not permit of much movement in any direction, 

 except the lateral. Therefore the downward turn, where 

 it cannot by reason of the force of the stream be effected 

 by means of the fin planes alone, has to be effected by a 

 sideways twist, the flash of which (as "the little brown wink 

 under water") has so often afforded to the wet-fly angler 

 the one hint that it is time for him to tighten on his fish. 

 Chalk and limestone streams generally present numerous 

 points of vantage where the stream, with or without the 

 aid of the wind, concentrates a steady sequence of surface 

 food, and it is at such points that trout will be poised, either 

 in shelter, ready to ascend, if the stream be strong, or near 

 the surface, if the stream be gentle. These points are gener- 

 ally under banks or at the tails of weeds from which the 

 ascending nymphs are shed, and these are accordingly the 



