270 BRITISH FRESH-WATER FISHES 
Artificial propagation, of the results whereof upon the stock 
of salmon in any river one has to speak with the reserve proper 
to imperfect experience, has been applied to trout with perfect 
success and certainty. A large number of commercial hatcheries 
have been established in various part of the United Kingdom, 
and there is now no difficulty in obtaining eyed ova, fry, year- 
lings, or mature trout for the purpose of stocking or replenishing 
lakes and streams. 
