THE MOUTH OF A TROUT 49 



If the angler in his bath makes the experiment of trying 

 from below water to catch some small floating object on 

 the surface, he will find it evade him again and again, 

 pushed away by the current set up by his approaching 

 hand, and it looks a miracle that the same thing should 

 not occur with the trout, especially when his approach 

 is swift. But if the feeding trout be watched as he rises 

 to the fly, it will be noted that there is, as he opens his 

 mouth, an expansion of the gills which carries a stream 

 of water, and with it the insect, in with a rush. What is the 

 process by which, on the water being ejected through the 

 gill, the fly, natural or artificial, is retained is not known 

 to me. It may be an operation of the tongue, but I think 

 not. In any case, until the water is sufficiently expelled 

 to enable the fish to feel or taste the capture, there is 

 necessarily an interval, which constitutes the angler's 

 opportunity, when that fly is his artificial one, to pull the 

 hook home. When the fish is taking larvae, or nymphs, or 

 other subaqueous life carried by the current, the process 

 is just the same. It is probable that if, in either case, the 

 fish lipped the hook or the gut, there would be an instan- 

 taneous ejection of the dangerous morsel. Taste (which 

 is, after all, a phase or development of the sense of touch) 

 would warn him that at best the object was indigestible 

 and unprofitable; experience might hint that it was 

 dangerous. When trout are well on they take with a big 

 gulp, often accompanied by a distinct " gluck " or smack 

 of the lips; but there are days when the fly seems to be 

 sipped in with a minimum of water through scarcely opened 

 lips, and on such days the angler is apt to miss an abnormal 

 proportion of rises. 



This, then, being the method of the trout in feeding, 

 one can readily see that minute accuracy of observation of 

 the relative parts of a fly, as regards arrangement and 



7 



