44 THE SALMON FISHEK. 



food there. In the Arctic rivers there is no spring 1 

 run of salmon, because the season does not open till 

 the latter part of June, on account of the ice, and 

 the advent and breeding of all marine forms is 

 retarded. The only run is in midsummer. There is 

 no autumn run, for the rivers are frozen tight by 

 ihe end of September. Low temperature makes 

 iishes sluggish. It benumbs them, just as it does 

 other creatures. Fishes do not travel as fast, or 

 play as well on a rod, at, say, thirty-five degrees of 

 temperature as at fifty-five. "While salmon are not 

 so sensibly affected by temperature of water as many 

 other fishes, it is a condition which operates mate- 

 rially against them in one way. The specific gravity 

 of stream water being greater at low temperature 

 than at high, salmon have a greater force to contend 

 with then in ascending the rivers, and consequently 

 sustained travel becomes laborious, and is impeded. 

 Cold weather makes a season late. River fish can- 

 not move into warmer quarters at will like salt water 

 fish, which make for the Gulf Stream on the advent 

 of hard frost, or when the ocean becomes chilled by 

 icebergs drifting, nor can they warm their cold- 



