THE SENSE OF FORM 13 



even some beyond the range of colour visible to man at 

 either or both ends of the spectrum ? I do not know, but 

 Nature is so marvellously various and so fertile in expedient 

 that I should hesitate to call it impossible that it should be 

 so. The subject is one which will bear a good deal more 

 thinking over and investigation than it has hitherto received, 

 and I propose to examine it at more length at a later stage. 



II 



THE SENSE OF FORM AND DEFINITION 



The trout is credited on authority with being the keenest- 

 eyed of animals, and doubtless most of us have too frequently 

 found him keener of sight than we have cared about. Yet 

 the nature and limitations of that keenness are well worth 

 examining if we are to get a working grip of the principle 

 which should underlie the art of trout-fly dressing. In 

 examining the question of the possibility of successfully 

 using imitations of larvae or nymphs for trout fishing, 

 Mr. F. M. Half or d, after supposing that the angler has 

 turned out a fairly good imitation of the nymph, and tries 

 it at a time when the fish are bulging incessantly at natural 

 larvae, says: 



" Alas ! how woefully is he desillusione. The fish will 

 not look at this, although it is an admirable representation, 

 both in colour and shape, of the natural insect. . . . How 

 is it to be expected that a timid, shy fish like a trout, who 

 from painful daily, and even hourly, experience is warned to 

 use the keenest of all the senses with which he has been 

 endowed by nature — viz., his sight for his protection, should 

 mistake that motionless, supine compound of dubbing, silk, 

 quill, and hackle, drifting helplessly and lifelessly like a log 

 down the stream, for the active, ever-moving larva sparkling 



