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- 
finerhent, 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 foreign 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 affect the issue, and that in many respects 
artificially reared smolts behave differently 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 
