50 POPULAR SCIENCE MONTHLY. 



not prove that the salmon are guided by a marvelous geographical instinct 

 which leads them to their parent river in spite of the fact that the river can 

 not be found. The waters of Russian River soak through these sand-bars, and 

 the salmon instinct, we think, leads them merely to search for fresh waters. 

 This matter is much in need of further investigation; at present, however, we 

 find no reason to believe that the salmon enter the Rogue River simply because 

 they were spawned there, or that a salmon hatched in the Clackamas River 

 is more likely, on that account, to return to the Clackamas than to go up the 

 Cowlitz or the Des ChQtes. 



Attempts have been made to settle this question by marking the 

 fry. But this is a very difficult matter, indeed. Almost the only 

 structure which can be safely mutilated is the adipose fin, and this 

 is often nipped off by sticklebacks and other meddling fish. The 

 following experiments have been tried, according to Mr. Davis : 



In March, 1896, 5,000 king salmon fry were marked by cutting off the 

 adipose fin, then set free in the Clackamas River. Nearly 400 of these marked 

 fish are said to have been taken in the Columbia in 1898 and a few more in 

 1899. In addition a few were taken in 1898, 1899 and 1900 in the Sacramento 

 River, but in much less numbers than in the Columbia. In the Columbia most 

 were taken at the mouth of the river where most of the fishing was done, but 

 a few were in the original stream, the Clackamas. It is stated that the fry 

 thus set free in the Clackamas came from eggs obtained in the Sacramento — 

 a matter which has, however, no bearing on the present case. 



In the Kalama hatchery on the Columbia River, Washington, 2,000 fry 

 of the quinnat or king salmon were marked in 1899 by a V-shaped notch in the 

 caudal fin. Numerous fishes thus marked were taken in the lower Columbia in 

 1901 and 1902. A few were taken at the Kalama hatchery, but some also at 

 the hatcheries on Wind River and Clackamas River. At the hatchery on 

 Chehalis River six or seven were taken, the stream not being a tributary of the 

 Columbia, but flowing into Shoalwater Bay. None were noticed in the Sacra- 

 mento. The evidence shows that the most who are hatched in a large stream 

 tend to return to it, and that in general, most salmon return to the parent 

 region. 



There is no evidence that a salmon hatched in one branch of a river 

 tends to return there rather than to any other. Experiments of Messrs. 

 Eutter and Spaulding in marking adult fish at Karluk would indicate 

 that they roam rather widely about the island before spawning. A 

 spawning fish set free in Karluk Eiver was found three days later at 

 Eed Eiver, sixty miles away on the opposite side of Kadiak Island. 



The introduction of salmon into new streams may throw some 

 light on this question. In 1897 and 1898, 3,000,000 young king 

 salmon fry were set free in Papermill Creek near Olema, California. 

 This is a small stream flowing into the head of Tomales Bay, and it 

 had never previously had a run of salmon. In 1900, and especially in 

 1901, large quinnat salmon appeared in considerable numbers in this 

 stream. One specimen weighing about sixteen pounds was sent to the 

 present writer for identification. These fishes certainly returned to 



