IMITATION OF THE NATURAL INSECT 135 



cessity for close imitation, especially in relation to 

 colour. In 1740 John Williamson stated the prin- 

 ciple in the following words: ". . . as the great 

 Difficulty is to obtain the Colour of the Fly which 

 the Fish take at the Instant of your Angling, it is 

 impossible to give any certain Directions on that 

 Head; because several Rivers and Soils are 

 haunted by peculiar Sorts of Flies, and the Flies 

 that come usually in such a Month of the Year, 

 may the succeeding Year come almost a Month 

 sooner or later as the Season proves colder or hot- 

 ter. Tho' some Fish change their Fly once or 

 twice in one Day, yet usually they seek not for an- 

 other Sort, till they have for some Days glutted 

 themselves with a former, which is commonly 

 when those Flies are near Death, or ready to go 

 out." Then, giving some simple instructions 

 in regard to tying flies, he quotes Walton: 

 " But to see a Fly made by an Artist is the best 

 Instruction; after which the Angler may walk 

 by the River, and mark what Flies fall on the 

 Water that Day, and catch one of them, if he 

 see the Trouts leap at a Fly of that Kind. ..." 

 Williamson's book was practically a compila- 

 tion, containing the best of what had been writ- 

 ten by anglers before him, together with his own 

 observations. 



