THE MIGRATION OF SALMON IN THE COLUMBIA RIVER. 
* 
By CHARLES W. GREENE, Ph. D., 
Professor of Physiology and Pharmacology, University of Missouri. 
J- 
ESTABLISHED FACTS AND THE UNSOLVED PROBLEMS. 
The life history of the anadromous fishes is one of the most interesting subjects 
in biology. The detail of facts surrounding the migration of the young from the fresh 
water to the sea and the migration of the adults to fresh water for spawning purposes 
are indeed little enough known of themselves. How much more shrouded in obscurity, 
therefore, must be the causes operating during these migrations. The United States 
Bureau of Fisheries has never ceased in its efforts to untangle this thread of piscatorial 
history. 
In the instance of the Pacific coast salmon of the genus Oncorhynchus , thanks to the 
labors of Evermann, Gilbert, Meek, Rutter, Chamberlain, and others, the following 
general facts are now established within a reasonable degree of certainty: 
i. The young of the species of Oncorhynchus , which have been hatched in the fresh- 
water streams, migrate to the sea, where they can secure an abundance of food during 
their developmental period. Evermann® in 1894 and 1895 observed many young 
O. tschawytscha and O. nerka in the Salmon River headwaters in Idaho. He says: “We 
are not yet able to say just when the young salmon leave the waters where they were 
hatched and begin their journey to the sea, but it undoubtedly occurs between September 
of the first and July of the second year following that in which they were spawned. 
Eater Rutter 6 followed the downward migration of young salmon in the Sacramento 
River, California. He found that young salmon fry “begin their down-stream migra- 
tion as soon as they are able to swim.” They reach the estuary in large numbers in from 
ninety to one hundred days or more. He found also that many young salmon “summer 
Evermann, B. W.: A preliminary report upon salmon investigations in Idaho in 1894. Bulletin U. S. Fish Com- 
mission, vol. xv, 1895, p. 253, 1896; and A report upon salmon investigations in the headwaters of the Columbia River 
in the State of Idaho in 1895, together with notes upon the fishes observed in that State in 1894 and 1895. Bulletin U. S* 
Fish Commission, vol. xvi, 1896, p. 184. 
b Rutter, Cloudsley: Natural history of the quinnat salmon. Bulletin U. S. Bureau of Fisheries, vol. xxn, 1902,, 
