NATURAL FOOD. 39 



utmost celerity on the approach of an enemy. These 

 muscles, then, or other shell fish taken from their shells, 

 form excellent bait, both for salt and fresh water fishes, 

 though nothing of this kind is in common use with 

 fresh water anglers, besides a paste made from shrimps. 



It has been supposed, that by feeding on three or 

 four sorts of shell fish, the common trout has its 

 stomach altered from a soft and membranous, to a 

 hard and fibrous texture, inaccurately said to be similar 

 to a fowl's gizzard. These trouts, which are called 

 gillaroo, are found in Loch Melvin, near Ballyshannon, 

 and Loch Con, near Ballina, in Ireland, and differ little 

 from the common trout, except in being of a bright 

 golden yellow on the belly and fins, with more red spots 

 on the sides, and somewhat broader and thicker in form. 



The following remarks of Sir H. Davy show that 

 the common opinion respecting the origin of this 

 difference, is at least very doubtful. Speaking of Loch 

 Melvin, he says, " the common trouts of this lake have 

 stomachs like other trouts, which never, as far as my 

 experience has gone, contain shell-fish; but of the 

 gillaroo trout, I have caught with a fly some not longer 

 than my finger, which have had as perfect a hard 

 stomach as the larger ones, with the coats as thick in 

 proportion, and the same shells within ; so that this 

 animal is at least now a distinct species, and is a sort 

 of link between the trout and char, which has a 

 stomach of the same kind with the gillaroo, but not 

 quite so thick, and which feeds at the bottom in the 

 same way. I have often looked in the lakes abroad for 

 gillaroo trout, and never found one." 



