MR. F. DAY ON BRITISH SALMOKES. 413 



largest Gillaroo is 12| lb. ; the smallest 2 lb. Tbere is a red 

 Gillaroo and a white ; the last is the smallest and the better eat- 

 ing. It is white with black spots on it ; the red Gillaroo is red 

 with black spots on it." 



Trout, as already remarked, are exceedingly liable to variation, 

 whether such is due to local or constitutional causes. Some of 

 these abnormal productions would seetn to be hereditary ; in 

 others the same exciting cause continuing in action occasions the 

 same results as in previous generations. Giraldus Carabrensis, 

 lib. iii. c. X., the traveller and Archdeacon of Brecon, who attended 

 Baldwin, Archbishop of Canterbury, in a progress through Wales 

 in 1188, tells us of trout existing in the lakes of Snowdon which 

 possessed only one eye. The Fischau, near Mandorf in Germany, 

 was reputed to contain blind trout (Fr. Ern. Bruckmanni Epist. 

 Itin. xxxvi, "Wolfenb. 1734, p. 10). A deformed race of trout is 

 asserted to exist in a small loch in Inverness-shire near Pitmain : 

 among them there appears to be an arrest of development in the 

 upper jaw, giving their heads a slight resemblance to those of 

 bulldogs, due to the projection of the lower jaw (Encyc. Brit. 7tli 

 ed., art. Aug.). In Loch Islay is a race of tailless trout. At 

 Malham Tarn, in Yorkshire, the trout are distinguished by a 

 deficiency or malformation of the gill-covers. On Plinlimmon, 

 and in adjacent parts of "Wales, are "hunch -backed" trout, having 

 deformed vertebral columns, as already alluded to. There are 

 likewise races in which some local cause has set up local action, 

 as of the stomach alone. This variety, due to the food it indulges 

 in, has the muscular coat of its stomach thickened, which ab- 

 normal structure has been reproduced in succeeding generations. 

 For it must not be assumed, because in certain examples we are 

 unable to find Limncsa and other shells, that the fish has never 

 consumed any ; they may have been digested, or it may have 

 varied its food, or the shells may have been temporarily unobtain- 

 able. But prior to considering this modification as of a specific 

 character, it may be worth while to ask whether such is solely 

 restricted to the Gillaroo, which, in the British-Museum Cata- 

 logue, vi. 1865, is termed Salmo sfomacJiicus, Giinther. 



Thompson (' Natural History of Ireland,' iv. 1856) justly ob- 

 serves that " the coats of other species of Salmones than S.fario 

 (of which only the Gillaroo is set doTVTi as a variety) become 

 muscular from the same cause. I have seen S. ferox, from dif- 

 ferent localities, with a muscular stomach ; and these examples 



