THE LIFE OF THE SALMON 237 



in the health-giving waters of the sea that a cure can be 

 effected, and instinctively, therefore, will the grilse or the 

 salmon turn and make his way to the sea whenever his scales 

 are destroyed and his skin torn. Thus it is not unlikely 

 that the actual spawning of a salmon may not take place 

 until it has spent four or five years in the sea, and this 

 delay may be accounted for by accidents which happen 

 to him on his former spawning trips, and compel his return 

 to the sea. 



The smolts of any one's year's migration will provide 

 spawning salmon for any one of the five following years. 

 The great majority of the fish of each migration which do 

 return, will do so during the next three years, while the 

 remainder of the returning fish from the same year's 

 migration will do so in the fourth or fifth succeeding year. 

 No other reason can be given for the irregular return 

 of each season's migrating fish than that due to a 

 provision of nature to insure a more certain distribution 

 or mixing on the spawning beds of the progeny of different 

 salmon. 



Salmon are irregular both as to the time of their return and 

 also as to the river they ascend. The early or late ascent 

 peculiar to different rivers by which they are known as 

 early and late waters is due to their temperature and local 

 climate, but each river may vary as regards the exact date 

 at which salmon run, being earlier or later as the river 

 alters in the volume of its flow. 



SPAWNING 



To return then, to our grilse or salmon ; he has at last 

 reached the gravelly beds of the upper stream of his own 

 river. Natural selection, possibly assisted by repeated 

 combat, will decide his mate, and the female salmon, when 

 her condition is ripe, lying on her side, will with lateral 



