138 Introduction of Salmon from, the 



disappeared: they are now "Smolts," and fully prepared 

 to leave the stream of their nativity and proceed to the 

 Ocean. 



It has not, I believe, been much questioned that these 

 Smolts are young Salmon ; but it has been alleged that 

 they are the first hatched of the fry of the same year, and 

 that the fish with the transverse bars are Parrs. Should 

 any one still doubt the identity of the Parr and the Smolt, 

 he has only to scrape away the silvery coating of outer 

 scales, when the transverse bars will again be distinctly 

 brought into view. The average length of the Smolt 

 appears to be about 5 inches. The season at which they 

 descend the rivers depends entirely upon the time at which 

 they have been spawned, and this chiefly upon temperature ; 

 the greatest numbers descend in April and May, a period 

 which corresponds with the principal spawning time, 

 November and December. 



Smolts, descending the rivers in April and May, have 

 been caught, marked, and returned to their native element ; 

 and in the course of June and July the same fishes have 

 been recaptured on their return from the sea — beautiful 

 Grilses, weighing from 3 to 8 pounds : the difierence in 

 weight being regulated by the length of their sojourn in the 

 salt water. This experiment has been repeated by difierent 

 persons, in different rivers and in different years, and 

 always with the same result. The Grilses, on their return 

 to the rivers, commence spawning in the same manner as 

 the Salmon, only earlier ; and in the next spring they again 

 descend to the sea, to return, after an absence of generally 

 about eight weeks, as perfect Salmon. The Salmon, after 

 spawning, go down to the sea again for the same period, and 

 return greatly increased both in size and weight. 



The Duke of Atlioll, who has taken a very deep interest 

 in endeavouring to trace out and ascertain the history and 



