16 SALMONID^E. 



ture of salt water, till they are inured to the change, when 

 they go off to the sea all at once. There, their growth 

 appears to be very rapid, and many return to the brackish 

 water, increased in size in proportion to the time they have been 

 absent. Fry marked in April or early in May have return- 

 ed by the end of June weighing from two to three pounds 

 and upwards. The London markets during the latter part 

 of June, and the months of July and August, exhibit fish of 

 the year varying in weight from two to six pounds. I have 

 one, here figured, that weighed only fifteen ounces, which, 

 judging from its appearance when I bought it, that it had 

 been to sea, is the smallest specimen I have ever seen that 

 had been once to salt water. 



These small-sized fish, when under two pounds' weight, are 

 called by some of the London fishmongers Salmon-Peal ; 

 when larger, Grilse. These fish of the year breed during the 

 first winter ; they return from the sea with the roe enlarged ; 

 the ova in a Grilse being of nearly the same comparative 

 size as those observed in a Salmon, but they mature only a 

 much smaller number. The Grilse visit the estuary, remain- 

 ing for a considerable time in the brackish water, afterwards 

 in the tide-way above, ultimately pushing up to the sources 

 of the tributary streams, and, as before observed, rather ear- 

 lier in the season, in the same river, than the more adult fish. 



