GENERAL FEATURES 65 



hut I am able to give a reproduction (Fig. 20) of a photograph of a sea- 

 trout which was caught in the coastal nets off the mouth of the river Aln 

 on 27th July, 1915. The fish, a male, weighed 3^ lb., and there is, so 

 far as I can see, nothing very distinctive in its appearance. Mr. J. J. 

 Hardy, of Alnwick, who kindly sent me the photograph, states that " it 

 is quite a typical fish for the Aln and Coquet." There is something to 

 be said about the scales, however, and their appearance must give one 

 pause. They are far more like the scales of a grilse than one would 

 expect to see in a sea-trout weighing as much as 3j lb. The reproduc- 

 tion of one of the scales here given (Fig. 21) clearly indicates, I think, 

 that the fish spent two years' residence in fresh water before its descent 

 to the sea as a smolt; thereafter it spent its third year in the sea, and 

 was apparently caught when making its first return to fresh water to 

 spawn in its fourth year. Now this would be exactly the life-story of 

 a grilse if the fish belonged to the species Salmo salar. It is, however, 

 undoubtedly a sea-trout, and the scales point to its being a maiden fish 

 in its fourth year; but, if so, one would in ordinary circumstances expect 

 it to weigh hardly more than at most i^lb., equivalent to the weight 

 which one is accustomed to recognise in those sea-trout which, failing 

 to ascend the river as whitling, ascend in the following year as maiden 

 fish. But this fish weighed 3J lb. 



Now, if one is to accept the foregoing scale reading as correct — and 

 there seems to me no good reason why one should not do so — some 

 interesting speculations suggest themselves. The fish may be an 

 ordinary sea-trout whose rate of growth has been abnormal, which is 

 unlikely. East Coast sea-trout, again, may all show an equally rapid 

 growth, which, in view of the data given by Mr. Malloch of Tay fish, 

 seems also unlikely. Finally it may, after all, be that the " bull trout " 

 is a distinct species, or race, whose rate of growth in the earlier stages 

 is practically equivalent to the rate of growth of the salmon grilse. 



I also reproduce here (Fig. 22) another sea-trout, weighing 8 lb., 



