136 U. S. BUEEAU OF FISHERIES. 



males and females equally conspicuous among their silvery compan- 

 ions. On subsequent dates these stragglers became more rare, and 

 when the party left for the upriver on August 2 the few chums that 

 were then running were almost wholly of the pronounced silvery 

 type. 



It is unfortunate that confusion should have arisen in the Yukon 

 from a failure to recognize that the dog salmon and the so-called 

 " silvers " represent different phases in the development of one and 

 the same species. 



The " dog salmon " are the individuals furthest advanced toward 

 spawning. They exhibit the elongated hooked jaws and enlarged 

 teeth in the male, the bright nuptial coloration, and the impover- 

 ished condition of the flesh, which is light in color, largely devoid of 

 oil, and possessing very little substance when dried. 



In the " silvers " the eggs and milt are less developed, the j aws of 

 the male are little or not at all hooked, the external coloration is sil- 

 A'ery, or with a light flush of red, and the meat is red in color when 

 dried, rich in oil, and valuable both for human food and for dogs. 



In general, the " dog salmon " along any stretch of the river con- 

 sist of those individuals which will turn into some adjacent tributary 

 to spawn, while the " silvers " are on their way to the upper reaches 

 of the river, show relatively little of the sexual changes they will ex- 

 hibit on their spawning beds, and are still richly provided with the 

 oil which serves as fuel and principal source of nourislmaent during 

 the long journey still before them. 



Many fishermen recognize the difficulty of distinguishing sharply 

 between " dogs '' and " silvers " and relieve their embarrassment by 

 recognizing a third class, the " half-breeds." But the term " silver 

 salmon " has acquired a fairly definite and useful significance in the 

 trade. " Dog salmon " are so poor in nourishment that they have 

 indifferent value even for dog feed, and will not be purchased except 

 during times of extraordinary scarcity. The natives will feed them 

 to their dogs, but will not eat them themselves unless king salmon and 

 " silver salmon " are unobtainable. 



The use of the term " silver salmon " for bright silvery chums, still 

 rich in substance, is so universal and of such long standing in the 

 interior of Alaska that it seems useless to attempt to supplant it with 

 any other name. Confusion Avill inevitably result owing to the pres- 

 ence of the totally different species, the coho, which is commonly 

 known in outside Avaters as the sih^er salmon. It is proposed, there- 

 fore, that the term " silvers," when referring to the Yukon basin, be 

 restricted to the chums known commercially by that name, Avhile the 

 three species of salmon of importance on that stream be known as 

 the king, the chum, and the coho. 



It became evident, as we were ascending the river in August, that 

 the " dogs " and the " silvers " were in general keeping apart from 

 each other and were following distinct migration routes. Through- 

 out the entire lower course of the Yukon, from Tanana at least as 

 far as Anvik, the "dogs" predominated on the right (north limit) 

 of the river and the "silvers" on the left limit. This is generally 

 recognized by all the fishermen of that region, w ho also agree that the 

 " dog salmon " turn into all the creeks and smaller tributaries, while 

 the silvers " dislike the taste of fresh water," as a native fisherman 

 stated the case. It is also recognized that a heavier run of kings and 



