Mr. J. Blackwall's Notes on the Salmon. 41 1 



seiTation and experiment plainly show. Salmon-fry from seven 

 to eight inches long, having all the characters of the parr, may be 

 taken in the Conway and its tributary streams in small numbers 

 in the month of June, after the smolts of the season have entirely 

 quitted those rivers, and, occasionally, I have obtained specimens 

 of still larger dimensions, weighing four ounces. The physical 

 cause, whatever it may be, which prevents these iish from acquiring 

 the migratory cbess and instinct of their species, evidently does not 

 prevent them from increasing in growth and improving in condi- 

 tion, even the males which have shed their milt presenting every 

 appearance of renovated health and vigour. 



Mr. Yarrell, in his ' History of British Fishes,' vol. ii. p. 21, 

 states that a large landed proprietor in Scotland, in April 1831, 

 put a dozen or two of small salmon-fry, three or four inches long, 

 into a newly-formed pond between three and four acres in extent. 

 No fishing was allowed in this pond till the summer of 1833, 

 when several of these salmon were taken, weighing from two to 

 three pounds, perfectly well-shaped, well-coloured, and well-tla- 

 voured. As these fish must have been in their second year when 

 put into the pond, it follows that they attained to the weight of 

 two or three pounds in rather more than three years. 



In the Supplement to the second volume of ]Mr. Yarrell's work 

 other examples of the growth of young salmon in fresh water are 

 given (pp. 5, 6), from which it appears that in one instance there 

 was an increase in weight of eleven or twelve ounces in sixteen 

 months, and in another instance an increase of fourteen or fifteen 

 ounces in twenty-seven months. 



I shall now proceed to inquire into the growth of the salmon 

 during its sojourn in the sea. 



Early in the month of June, salmon in high condition, ranging 

 from three to five pounds in weight, ascend the Conway in con- 

 siderable numljers if the state of the water be favom-able ; but that 

 they cannot be identical with the smolts of the same year is ma- 

 nifest, because the inversion of established physiological principles 

 is involved in the opposite supposition ; for as great numbers of 

 grilse weighing from half a pound to a pound come up the same 

 river in August, full two months later than the former, there is 

 no escaping from the unphilosophical conclusion to which such a 

 hypothesis leads ; namely, that young salmon decrease in size as 

 they increase in age. To avoid the awkwardness of this dilemma, 

 it is only necessary to admit the identity of the small grilse which 

 ascend the Conway in August with the smolts of the preceding 

 spring ; and this view of the subject, which, if correct, completely 

 subverts the theory of the all but preternatural growth of the sal- 

 mon in salt water, derives support from the gradual increase of 

 2E 2 



