4 THE LIFE OF THE SALMON 



has been made in England, and the results deduced 

 from them have been to show that the grilse had 

 been a whole year away from fresh water. I refer 

 to the experiments conducted in the Tavy in 

 Devonshire by the direction of the Duke of Bedford. 

 Here the method of marking was the same, but the 

 deduction different. I am not aware what the 

 appearance of the mutilated fin was in those 

 Devonshire grilse, but in Ireland, where some adult 

 fish marked with a label on the dorsal fin were also 

 marked " by a wide notch cut far into the adipose 

 or dead fin,"* it was ascertained that when one of 

 those fish was recaptured *' the fin had recovered its 

 usual form, the outline of the notch being just 

 visible as a faint scar." With smolts kept in con- 

 finement, after mutilating the fins it has also been 

 found that the mark healed up, so that there was 

 considerable ground for the belief held by not a few 

 that this method of marking without the attachment 

 of some foreiofn substance was not reliable. 



A good deal of additional information as to the 

 growth and migration of smolts has been obtained 

 by the numerous hatching and rearing operations 

 which have been carried on all over the country. It 

 is undoubtedly the case that the artificial conditions 

 materially afiect the issue, and that in many respects 

 artificially reared smolts behave difierently from those 

 in the wild state. The steady and abundant food 

 supply increases the rate of growth, and apparently 

 exaggerates the variation which may exist. For 



*■' Holt, "Report of Sea and Inland Fisheries of Ireland for 1901," 

 part ii. p. 181 



