NATURAL FOOD. 89 



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 a gillaroo 

 trout, and never found one." 



