50 THE LIFE OF THE SALMON 
half years later off an island on the coast more 
than 90 miles distant from the river where it was 
marked. It then weighed 18 lb. The unusual 
size it had attained, coupled with the fact that it was 
taken much nearer to rivers frequented by large fish 
than the Figgen river, is at least suggestive of 
the idea that the explanation of some rivers holding 
fish of a much smaller average size than others may 
be due to the fish seeking new rivers after they have 
attained a certain size.” 
In a chart showing migrations of salmon along the 
coast of Scotland * are five lines indicating move- 
ments of marked fish from the river Deveron, 
which debouches on the southern shores of the 
Moray Firth, to the east coast nets near Aberdeen. 
Three of the five fish referred to were grilse, and in 
each case this rather marked migration had been 
made in four months or less. We have of course no 
proof that those fish would not have travelled back 
again, but I certainly consider such a return unlikely. 
The great majority of marked fish, grilse as well 
as salmon, are found again in the rivers in which 
they were marked, but such cases are suggestive of 
the possibility referred to above. Yet after the con- 
siderable amount of salmon marking which has now 
been carried out in Scotland, it is natural to sup- 
pose that if such a transference occurred frequently 
in our rivers, more direct evidence of it would by 
this time have been obtained. 
I have made reference to the large proportion of 
* Twenty-fourth Annual Report, Fishery Board for Scotland, 
Part IT. p. 69. 
