Feeding in Fresh Water 167 



demonstrates its generic affinities as clearly as do 

 its anatomical characters. 



At the spawning season the jaws of the male 

 steelhead undergo some changes, but not to the 

 great extent that they do in the salmon. 



Feeding in Fresh Water 



It may be accepted as an established fact that 

 the Pacific salmons do not feed in fresh water 

 except in rare instances. After leaving tide 

 water the throat becomes contracted, and dissec- 

 tion shows no food in the stomach. 



The tendency to feed becomes less the longer 

 they remain, and when one has seen the enormous 

 runs of salmon that sometimes actually crowd 

 the streams, so that it would be impossible to wade 

 without stepping upon them, it becomes apparent 

 that they could not make their rapid journeys to 

 the head waters of the largest rivers and have time 

 to feed, and that there could not be food enough 

 to supply them if they required it. If such hordes 

 should become hungry while on the spawning 

 grounds hundreds of miles from the sea, one could 

 imagine the effect on the spawning operations. 



As a matter of fact the salmon, after leaving 

 tide water, lives on its own supply of fat and 



