THE SALMON. 241 



asserted, but is due to deposition of silvery pigment on 

 the under-surface of the scales and opercles. Dr. Giinther 

 considers that a new coat of scales overlays the parr- 

 marks. 



Usually the smolts do not go direct to the sea, but 

 remain for a short time in the brackish water, to acclima- 

 tise themselves, as it were, to the change, and then go 

 farther into the salt water whether in the estuaries only 

 or direct to the sea is not precisely ascertained ; but they 

 go where they find a great abundance of the food necessary 

 for their rapid growth, for no such rapid growth in any 

 other department of the animal kingdom is known as that 

 of the salmon as it passes from the smolt to the grilse 

 state of its existence. Marked smolts which have gone 

 down to the sea in the spring some six or eight inches 

 in length, and weighing from 5 to 7 oz., have returned 

 in the autumn from 2 to 8 Ibs. in weight, and even 

 heavier. 



Mr. Willis Bund (loc. cit.) says: "Wherever it is that' 

 smolts go, the next question is, How long do they stay ? 

 It is usually answered, a year, or even less; that is, that 

 the smolts which go down one spring will return as grilse 

 certainly the next year, possibly before. There is really 

 no evidence to show this is correct, and judging from the 

 previous growth of the fish it seems very likely it is not. 

 At the lowest computation, it has taken a smolt a year 

 (more likely two) to reach the size of six inches, and that 

 under favourable circumstances as to food and water and 

 climate. Why should he in the second year of his life 

 grow three or four times as much as in his first year, and 

 increase from ounces to pounds ? It may be so, but it is 

 so contrary to what one would expect that one requires 

 some strong evidence to make us feel sure it is so." 



Unless we disbelieve the Stormontfeld and other ex- 

 periments, the evidence is strong enough to prove that at 

 least a good many smolts of the spring return as grilse in 

 the autumn of the same year. 



Mr. Young of Invershin, in April and May 1837, 

 marked a great number of descending smolts by making a 



Q 



