NATURAL HISTORY OF BRITISH SALMONID^. 171 



same time. From the experiments of Dr. Davy, elsewhere 

 commented upon, it appears probable that at least a propor- 

 tion of trout, like some salmon, spawn only in alternate years. 

 The situation chosen for, and the mode of conducting the 

 spawning process are very similar to those noticed in the 

 salmon— the eye. however, of the young fish becoming visible 

 in about three weeks, and the egg being usually hatched in 

 from forty to fifty days. 



The yolk bag is absorbed in from three to five weeks ; and 

 in six. weeks or two months the young fly are about an inch 

 long and able to shift for themselves. From this time their 

 growth is rapid or slow according to the nature and quantity of 

 their food and other local circumstances. 



THE GREAT LAKE TROUT. {Sa!mo ferox.) 



This fisn is the * Ullswater trout ' and ' grey trout ' of the 

 English lake district, and the ' Buddagh ' of Lough Neagh, 

 where the smaller fish bear the local name of ' dolachans.' 

 Though probably distributed throughout almost all the larger 

 and deeper lakes of Scotland, it is, perhaps, best known amongst 

 fishermen as the species for w^hich Loch Awe is celebrated. 

 It is found, to my own knowledge in Lochs Ericht, Lochy, 

 Garry, and Laggan, and has also been recognised in Loch 

 Shin, Loch Rannock, in Lochs Loyal and Assynt, and amongst 

 some of the Orkney and Shetland Islands. 



Besides Lough Neagh, the Great Lake trout is an inhabitant of 

 all the largest Irish lakes — Loughs Mask, Melvin, Earn, Corrib, 

 &c. — and is, in fact, almost wholly confined to similar great 

 lakes and deep extensive tracts of water, where it reigns in 

 more or less solitary grandeur, never leaving the lake except 

 for the purpose of spawning — a process which commences 

 about September or October-^and then seldom venturing far 

 up or down the tributary lake streams. In the river Awe, for 

 example, the outlet from the lake best known in connection with 



