SECOND DAY.] GILL AROO. TROUT. 55 



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 charr, 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. In a small 

 lake at the foot of the Crest of the Brenner, above 

 4000 feet above the level of the sea, I once caught 

 some trout, which, from their thickness and red 

 spots, I suspected were gillaroo, but on opening the 

 stomach I found I was mistaken ; it had no particular 

 thickness, and was filled with grasshoppers : but there 

 were charr, which fed on shell-fish, in the same lake. 



POIET. Are water-flies found on all rivers ? 



HAL. This is a question which I find it impossible 

 to answer ; yet from my own experience I should 

 suppose, that in all the habitable parts of the globe 

 certain water-flies exist wherever there is running 

 water. Even in the most ardent temperature, gnats 

 and musquitoes are found, which lay their congeries 

 of eggs on the water, which, when hatched, become 

 first worms, afterwards small slirimp-like aurelise, and 

 lastly flies. There are a great number of the largest 

 species of these flies on stagnant waters and lakes, 

 which form a part of the food of various fishes, 



