144 SALMON AND TROUT. 
One half of the young fry migrate when about a year old— 
almost all the other half at their second year—and the few 
remaining at their third year—but the period of the descent is 
very generally the same in either case—and in all rivers, whether 
early or late—beginning in March and continuing through 
April, May, and the early part of June—only a few fish con- 
tinuing to migrate during the subsequent months. 
The length of the smolt when migrating varies from three 
and a half to seven or eight inches, according to age and other 
circumstances. 
Its full colours are, dark blue or bluish green on the upper 
half of the body and head, with black or carmine coloured 
spots ; gill covers and lower half of the body silvery, and all the 
fins much darker than those of the parr. The silver scales 
come off on slight pressure and the parr marks are visible 
below. What becomes of the young fish after reaching the sea 
is still, more or less, a matter of conjecture. What we do know 
positively is, that in from six to eight weeks a number return 
to the same river with an increase in weight of from two to five 
pounds, and that many of the fry marked when migrating as 
smolts in May and June, are sold in the London markets as 
grilse in July, August, and September. It is a fair point for 
conjecture, and would be an interesting subject for future ex- 
periment, whether the grilse returning the same season may 
not consist principally of the ¢z0-year-old smolts, and so on ; 
or whether, should this prove not to be the case, these older 
smolts may not represent the larger-sized grilse, and the younger 
fish the smaller ones. 
The following is the actual growth of some smolts marked 
at Stormontfield, when on their way to the sea, and captured on 
their return as grilse during the same year : 
Weight Weight 
jJuy x1. « « 3 lbs. July 31 ‘ . « 98 Ibs, 
July2o . i » 5% lbs, Aug. 4 . 5 e 7% Ibs, 
Julyy2r .« «6 « 5 lbs. Aug. 4 ee - 8 lbs, 
Julygo. . - 7% lbs. 
Of the habits and food of the salmon in its various stages 
