THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



No. 72. JUNE 1843. 



LVI. — Notes on the Salmon. By John Blackwall^ F.L.S. 



To Mr. Shaw of Drumlanrig belongs the merit of having suc- 

 cessfully developed the natural history of the small fish denomi- 

 nated Parr, whose ceconomy, prior to the enunciation of his chs- 

 coveries, was involved in obscurity, and was the occasion of much 

 pei-plexity and hypothetical reasoning among British ichthyolo- 

 gists. By a series of well-conceived and skilfully conducted 

 e>q)eriments he has not only proved that the parr is neither a 

 hybrid nor a species mi generis, but has clearly established the 

 interesting and important truth that it is the young of the 

 salmon. 



Residing in the immediate vicinity of the river Conway, for 

 some years past my attention as a naturalist and a fly-fisher has 

 been directed to the finny inhabitants of its waters, and to the 

 salmon in particular. In the course of my researches several 

 remarkable facts relative to the latter species in its earlier stages 

 of grov\i:h have come under my observation; 1st, that young 

 males, exhibiting all the characters of the parr, frequently have 

 the lobes of milt fully matured, while females of the same size 

 have the lobes of roe in so backward a state that it is necessary 

 to employ a magnifier in order to distinguish the ova ; 2nd, that 

 these males shed their milt in the ensuing vxdnter months ; 3rd, 

 that the males of salmon-smolts are found to have shed their milt 

 before they descend to the sea, though the lobes of roe in the 

 females are then of veiy small dimensions ; and 4th, that smolts 

 may be made to assume the barred appearance of parrs by care- 

 fully removing their silvery scales. 



Perceiving that Mv. Shaw, in his " Experimental Observations 

 on the Development and Growth of Salmon-fry," published in the 

 fourteenth volume of the ' Transactions of the Royal Society of 

 Edinburgh,^ had noticed the phsenomena enumerated above, which 

 serve, however, in some measure, to corroborate the accuracy of 

 his views, I put aside my notes in which they are recorded, and 

 probably never might have recurred to them again had not an 

 abstract of a paper " On the Growth of the Salmon," by Mr. John 



A7m. ^ Mag. N. Hist. Vol. xi. 2 E 



