ME YOUNG ON THE GROWTH OF GRILSE AND SALMON. 347 



List of Grilse marked after having Spawned, and recaptured as Salmon, on their second ascent 



from the Sea. 



Period of Marking. 



1041, February 18. 



18. 



18. 



18. 



18. 



18. 



March 4. 



4. 



4. 



1842, January 29. 



29. 



29. 



March 8. 



January 29. 



... March 8. 



January 29. 



In the year 1841, we marked a few spawned salmon along with the grilse. 

 We marked both kinds in the back fin, but the salmon with copper wire, and the 

 grilse with brass wire. I perceive by my lists, that a salmon marked on the 4th 

 of March, returned and was captured on the 10th of July, with an increase of 

 6 lb., having grown in that time from 12 to 18 Ib. In 1842, however, we marked 

 no salmon ; all were grilse of 4 lb., and were marked in the caudal fin. In the 

 course of both seasons we caught far more marked grilse returning with the form 

 and attributes of perfect salmon than are recorded in my lists. 'In many speci- 

 mens the wires had been torn from the fins, either by the action of the nets or 

 other casualties ; and although I could myself recognise distinctly that they were 

 the fish I had marked, I kept no note of them. All those recorded in my lists 

 returned, and were captured with the twisted wires complete, the same as the 

 specimens transmitted for your examination. 



I think that the preceding facts, viewed in connection with Mr SHAW'S obser- 

 vations, entitle us to say that we are now well acquainted with the history and 

 habits of the salmon, and its rate of growth from the ovum to the adult state. 

 The young are hatched during a period which admits of considerable range, ac- 

 cording to the temperature of the season, and the character of special places. 

 Their growth in the early state of parr is extremely slow, and the silvery aspect 

 of the smolt is not assumed till at least the lapse of a year from the time of 

 hatching. The great mass of smolts descend to the sea during the months of 

 April and May, but not the whole, because the varying range of the spawning 

 season carries with it a somewhat corresponding range in the assumption of the 



VOL. XV. PART III. 5 A 



