THE LIFE OF THE SALMON 233 



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 meteoro- 

 logical conditions of each season. In unconfined water, 

 therefore, close observation can only attempt approximate 

 conclusions as to the times at which the parr of any par- 

 ticular season's hatch change into the smolt, and as to the 

 sexes affected at the various times of this change. It may be 

 assumed that meteorological conditions affect the periods 

 over which the parr stage extends, and it is not improbable 

 that the male parr is, as a rule, the first to leave that state. 



THE AIM OF NATURE 



There is, so far as I know, no evidence to disprove this 

 suggestion, while there are many arguments in favour of its 

 consideration. Nature and the laws of natural selection 

 are opposed to inbreeding, the aim of Nature appearing 

 always to favour the union of the sexes of different stocks. 

 The migration, therefore, of the male fish in the first spring 

 would, on his return from the sea, throw him into contact 

 with the female of another generation, and most probably 

 of other parentage, and so on. 



It may be assumed that a minority of parr in any one 

 season's hatch migrate after one year's river life, that a large 

 majority of those left behind as parr migrate after two years, 

 and the small remainder, probably the weaker ones, after 

 the third year. 



But, whatever may be the approximate facts, food and 

 temperature will be serious factors in the development of 

 the smolt and the time of its migration to the sea. 



We will now follow the smolt of the first year as he darts 

 with a multitude of his fellows from the river into the sea. 



He has at this time all the well-known characteristics 

 of the salmon both in appearance and habits, and he is yet 



