Flies and Fly-fishing. 313 



a buck-shot, and of a consistency so indurated as appar- 

 ently to preclude the possibility of any change of form. 

 Therefore, it seems to me trout must necessarily be quite 

 near-sighted, and consequently lack the power to distin- 

 guish details of form except within very narrow limits. 

 And it is believed that this defect in vision extends more 

 or less to all fishes; for though I have myself dissected the 

 eye of the trout v and one other variety of fish only, still 

 the treatises on comparative anatomy lead me to believe 

 that the eyes of all are constructed in substantially the 

 same manner. 



Is not the action of trout towards the artificial fly just 

 what this would lead us to expect? Place the natural 

 insect and its artificial copy side by side, and is the re- 

 semblance sufficiently close to deceive the human eye for 

 a single moment? Though in color they may be ap- 

 proximately similar as to form, only the eye of charity 

 can detect a resemblance. Color trout can undoubtedly 

 distinguish at some distance, as well as that there is an 

 object apparently edible trespassing on their domain, but 

 it would seem that details of form are only perceptible 

 at close quarters. 



Motion of any body large enough to do them an in- 

 jury they are prompt to perceive. In no element is the 

 struggle for life so bitter. To eat others and to avoid 

 being eaten are the sole occupations of the greater part 

 of a fish's life. Constant vigilance against the approach 

 of their many enemies is with them the price of life ; 

 therefore, nothing terrifies them so much as motion, and 

 all the more since their imperfect vision fails accurately 

 to apprise them whether the moving body is friend or foe. 



The foregoing applies to leaders as well as to any 

 other moving object ; and since at some point between 



