46 BRITISH FRESHWATER FISHES 



This leads us to the consideration of the so-called 

 land-locked Salmon, such as those of Lake Wenern 

 in Sweden, which are now cut off from the sea by 

 inaccessible falls, but which grow to a large size. 

 In Eastern North America some of the large lakes 

 in the New England States and in Quebec are 

 inhabited by non-migratory Salmon, including the 

 famous Ouananiche, which rarely grows larger than 

 7j Ibs., but is a very game and active fish. We 

 can readily understand that in large lakes with an 

 abundant food-supply some of the Salmon might 

 be induced to give up their journey to the sea, 

 and if in the course of ages such lakes became 

 inaccessible from the sea they would be inhabited 

 by a race of land-locked Salmon. 



There are no natural land-locked Salmon in the 

 British Isles, but a smolt was sent to me from 

 Lough Mask in June 1907 by Mr. Alick Duncan, 

 who wrote me that the only outlets for the lake were 

 crevices by which the water flows through under- 

 ground channels to Lough Corrib, three miles distant, 

 so that it is pretty certain Salmon do not run up 

 to Lough Mask at the present day, and they have 

 probably been introduced and seem to breed there. 

 In 1 88 1 Mr. Douglas Ogilby turned some smolts 

 into Lough Ash in Tyrone, which has no access to 

 the sea ; two years later he captured one of them 

 as a ripe female only 14 \ inches long, and it is 

 possible that this lake also now possesses a stock 

 of non-migratory Salmon. 



Enough has been said to show that sea-feeding 

 is not essential for the ripening of the sexual products, 

 since male Salmon may become mature in the parr 

 stage, and female Salmon, prevented from going 



