128 SALMON AND TROUT. 
9. In at least many cases, smolts thus migrating to the sea 
in May and June return as grilse, sometimes within five, 
generally within ten weeks, the increase in weight during that 
period varying from two to ten pounds, the average being from 
four to six pounds; and these grilse spawn about November or 
December—go back to the sea—and (in many cases) reascend 
the rivers the next spring as salmon, with a further increase of 
from four to twelve pounds. Thus, a fish hatched in April 
1854, and marked when migrating in May 1855, was caught 
as a salmon of twenty-two pounds weight in March 1856. 
10. It appears certain, however, that smolts do not always 
return during the same year as grilse, but frequently remain 
nine or ten months in the sea, returning in the following spring 
as small-sized salmon. 
[4oze.—It will thus be seen that the fry of salmon are called Jarzs until 
they put on their migratory dress, when they become smolts and 
go down to the salt water; g77dse if they return from the sea during 
the first year of their migration ; and at all other periods salon. ] 
11. It has also been clearly proved that, in general, salmon 
and grilse find their way back to spawn to the rivers in which 
they were bred—sometimes to the identical spots—spawn 
about November or December—and go down again to the sea 
as ‘spent fish,’ or ‘ kelts,’ in February or March—returning, in 
at least many cases, during the following four or five months as 
‘clean fish,’ and with an increase in weight of from seven to 
ten pounds. 
[Vore.—Shortly before spawning, and whilst returning to the sea as 
kelts, or spent fish, salmon are unfit for food, and their capture is 
then illegal. ‘Foul fish’ before spawning are, if males, termed red 
fish, from the orange-coloured stripes with which their cheeks are 
marked and the golden orange tint of the body; the females are 
darker in colour, and are called black fish. ] 
The foregoing still. represents, in a condensed form, our 
positive knowledge as regards the leading facts of salmon 
history. 
The irregular return of salmon from the sea, referred to in 
