Salmonidz 299 
beginning in late June in Chilcoot River, where some were 
found actually spawning July 15; beginning after the middle 
of July in Frazer River. 
As the season advances, smaller and younger salmon of these 
species (quinnat and blue-back) enter the rivers to spawn, and 
in the fall these young specimens are very numerous. We have 
thus far failed to notice any gradations in size or appearance 
of these young fish by which their ages could be ascertained. 
It is, however, probable that some of both sexes reproduce at 
the age of one year. In Frazer River, in the fall, quinnat male 
grilse of every size, from eight inches upwards, were running, 
the milt fully developed, but usually not showing the hooked 
jaws and dark colors of the older males. Females less than 
eighteen inches in length were not seen. All of either sex, large 
and small, then in the river had the ovaries or milt developed. 
Little blue-backs of every size, down to six inches, are also 
found in the upper Columbia in the fall, with their organs of 
generation fully developed. Nineteen-twentieths of these young 
fish are males, and some of them have the hooked jaws and red 
color of the old males. Apparently all these young fishes, like 
the old ones, die after spawning. 
The average weight of the adult auance in the Columbia, 
in the spring, is twenty-two pounds; in the Sacramento, about 
sixteen. Individuals weighing from forty to sixty pounds are 
frequently found in both rivers, and some as high as eighty or 
even one hundred pounds are recorded, especially in Alaska, 
where the species tends torun larger. It is questionable whether 
these large fishes are those which, of the same age, have grown 
more rapidly; those which are older, but have for some reason 
failed to spawn; or those which have survived one or more 
spawing seasons. All these origins may be possible in individual 
cases. There is, however, no positive evidence that any salmon 
of the Pacific survives the spawning season. 
Those fish which enter the rivers in the spring continue their 
ascent till death or the spawning season overtakes them. Doubt- 
less not one of them ever returns to the ocean, and a large pro- 
portion fail to spawn. They are known to ascend the Sacra- 
mento to its extreme head-waters, about four hundred miles. 
In the Columbia they ascend as far as the Bitter Root and Saw- 
