SIZES OF FLY. 113 



tion of flies in point of size to the season of the year 

 and the state of the water, because this subject is so 

 intimately connected with the habits of the trout 

 during the different fly-fishing months, that it is 

 impossible to separate them, and we shall therefore 

 discuss them together ; but before commencing, we 

 may remark, that a knowledge of the habits of the 

 trout is the most necessary of all information to the 

 angler. He may have the best tackle and the best 

 flies, and be skilled in the art of throwing them 

 lightly ; but unless he knows where feeding trout 

 are to be found, he will never achieve great success. 

 The two great causes which should regulate 

 the angler in selecting the size of fly to be used are 

 the colour and size of the water, and the wariness of 

 the trout ; the fly, in fact, must be large enough to 

 ensure its being seen, but not so large as to enable the 

 trout to detect its artificial nature. When a river 

 is large and dark-coloured, flies may be used a size 

 or two larger than when it is clear ; as in such cir- 

 cumstances it requires larger flies in order to be 

 seen, and the thickness of the water prevents trout 

 from detecting their artificial nature, as they would 

 if the water was clear. In a dark windy day, a size 

 or two larger may be used than in a calm sunny one, 

 as the roughness of the water and the darkness of 

 the sky prevent trout from seeing the flies so dis- 

 tinctly ; therefore, the clearer the water and brighter 

 the day, the smaller should the fly be, and the 

 thicker the water and darker the day, the larger 



