1386 U. S. BUREAU 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 ight in color, largely devoid of 
oil, and possessing very little substance when dried. 
In the “ silvers” the eggs and milt are less developed, the jaws of 
the male are little or not at all hooked, the external coloration is sil- 
very, 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 nourishment 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 will inevitably result owing to the pres- 
ence of the totally different species, the coho, which 1s commonly 
known in outside waters as the silver 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, while 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, who 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 
