SMOLTS 3 



an offence as serious as the time-honoured crime of 

 sheep-stealing, but robbed the observers of informa- 

 tion which might have saved them from much 

 subsequent error. 



Various batches of smolts before descending from 

 Stormontfield were marked by removing or mutilat- 

 ing in some particular way the adipose fin. A 

 limited number were also marked by the attachment 

 of small rings. About the same time (1864) the 

 Tweed Commissioners were conducting some valuable 

 experiments of a similar kind. None of the Tay sraolts 

 marked by the attachment of the rings were recovered, 

 but three at least of the Tweed smolts which had been 

 marked by the attachment of wire were recovered as 

 grilse in the Tweed after a year's absence, one in 1855 

 and two in 1856, the first weighing 3^ lb., the second 

 and third weighing each 6^ lb. In spite of these, how- 

 ever, it was contended, with the publication of many 

 particulars, that the Tay smolts marked by fin-cutting 

 were freely recaptured as grilse of three pounds and 

 upwards, after intervals varying from one and a half 

 to three months, and as a result it became very 

 generally believed, in Scotland at least, that the 

 grilse of our rivers caught in May, June, and July, 

 or later in the season, had only descended as smolts 

 in the spring of the same year, and were therefore 

 only 2 years old. Other and similar fin-cutting 

 experiments were made elsewhere in Scotland, with 

 apparently the same results ; and illustrations accom- 

 panied certain of the reports to show there could be 

 no mistake about the conclusion. Curiously enough, 

 in the last few years a similar series of observations 



