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lantic salmon is found. A glance at the map shows that sal- 

 mon streams of the Pacific coast are very short, and we know 

 that they are snow-fed. My theory is that those streams are 

 colder at the bottom than ours and that when this Western 

 salmon matured, if it ever did, it could find no suitable stream 

 to enter on our coast. Temperature is the thing which in- 

 fluences the migration of fish more than even food, and if 

 there is a strata of cold water in the Sacramento river, com- 

 ing down from the perpetual snows that feed tributaries a 

 short distance above, as I think very probable, then the rea- 

 son why the fish did not enter our warm rivers in May and 

 June is plain. It is possible that there may be a difference 

 of thirty degrees, Fahrenheit, between the bottom and the 

 surface of the Sacramento river in June. I know nothing of 

 these temperatures and this statement is mere theory, but it 

 is the only theory which I can frame to fit the facts. 



Dr. Hudson. — The planting of the California salmon in 

 the rivers of the Atlantic coast was an experiment that many 

 of us watched with great interest. We believed that it was 

 adapted to warmer waters than our own salmon, and the 

 young swarmed in our rivers and went to sea in good condi- 

 tion and in fair size, giving hope of their return, which was 

 never fulfilled. Why they did not come back has been a 

 puzzle to us and this theory, which has just been stated by 

 Mr. Mather, seems to be the only solution of the question. 



Dr. Gary. — We planted thousands of them in the rivers 

 of Georgia, but none returned. My theory accords with that 

 of Mr. Mather, the rivers are too warm. 



Prof. Goode. — The Germans have kept this California 

 salmon in ponds and report that they thrive under pond cul- 

 ture ; their success seems to be better than ours. It is cer- 

 tain that if this species was at all adapted to live on our East- 

 ern coast it would have lived in some of the streams between 

 Maine and Georgia, for no fish that has been introduced has 

 had a greater chance to find suitable conditions to live in 

 than this one. Every condition of food and temperature that 



