CHAPTER VI 



The physiological change of the parr into the smolt The natural 

 arguments in favour of the earlier change of the male parr 

 The smolt's life Appetite and growth in salt water The 

 grilse and his return The run up to the spawning-ground 

 The dangers of the ascent When injured Arrival at the 

 spawning-bed Selection of a mate Spawning Making the 

 redds Appearance of the grilse The kelt and the well- 

 mended kelt. 



A CONSIDERABLE difference of opinion, however, exists 

 as to this change of the parr into the smolt not 

 only as regards the percentages of fish in each year's 

 hatch which leave in the spring of the following or 

 succeeding year, but also as to the sex of those which 

 change during these years. 



It has so far been impossible to determine this 

 question with certainty, even in regard to the results 

 of each particular year's hatch of domesticated alevin. 

 How much more difficult is the problem where wild 

 fish have to be considered. As regards wild parr, their 

 change into the smolt stage should bear an intimate 

 relationship to the particular locality and the food, as 

 well as to the meteorological conditions of each season. 

 In unconfined water, therefore, close observation can 



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