156 LOWER VERTEBRATES. 



The males have : (a.) The premaxillaries and the tip of the lower jaw more and 

 more prolonged, both of them becoming finally strongly and often extravagantly 

 hooked, so that either they shut by the side of each other like shears, or else the 

 mouth cannot be closed, {b.) The front teeth become very long and canine-like, their 

 growth proceeding very rapidly, until they are often lialf an inch long, (c.) The teeth 

 on the vomer and tongue often disappear, (d.) The body grows more compressed and 

 deeper at the shoulders, so that a very distinct hump is formed ; this is more devel- 

 oped in O. gorbuscha, but is found in all. (e.) The scales disappear, especially on the 

 back, by the growth of spongy skin. (_/".) The color changes from silvery to various 

 shades of black and red, or blotchy, according to the species. The blue-back turns 

 rosy red, the dog salmon a dull, blotchy red, and the quinnat generally blackish. 



These distorted males are commonly considered worthless, rejected by the canners 

 and salmon-salters, but preserved by the Indians. These changes are due solely to 

 influences connected with the growth of the testes. They are not in any way due to 

 the action of fresh water. They take place at about the same time in the adult males 

 of all species, whether in the ocean or in the rivers. At the time of the spring runs, 

 all are symmetrical. In the fall, all males, of whatever species, are more or less dis- 

 torted. Among the dog salmon, which run only in the fall, the males are hook-jawed 

 and red-blotched when they first enter the Strait of Fuca from the outside. The 

 humpback, taken in salt water about Seattle, have the same peculiarities. The male 

 is slab-sided, hook-billed, and distorted, and is rejected by the canners. No hook-jawed 

 females of any species have been seen. It is not positively known that any hook- 

 jawed male survives the reproductive act. If any do, their jaws must resume the 

 normal form. 



On first entering a stream the salmon swim about as if playing ; they always head 

 towards the current, and this ' playing ' may be simply due to facing the flood-tide. 

 Afterwards they enter the deepest parts of the stream and swim straight up, with few 

 interruptions. Their rate of travel on the Sacramento is estimated by Stone at about 

 two miles per day ; on the Columbia at about three miles jier daj-. 



As already stated, the economic value of any species depends in great part on its 

 being a ' spring salmon.' It is not generally possible to capture salmon of any species 

 in large numbers until they ha-v'e entered the rivers, and the spring salmon enter the 

 rivers long before the growth of the organs of reproduction has reduced the richness of 

 the flesh. The fall salmon cannot be taken in quantity until their flesh has deteriorated ; 

 hence the ' dog salmon ' is practically almost worthless, except to the Indians, and the 

 hump-back salmon is little better. The silver salmon, with the same breeding habits 

 as the dog salmon, is more valuable, as it is found in Puget Sound for a considerable 

 time before the fall rains cause the fall runs, and it may be taken in large numbers 

 with seines before the season for entering the rivers. The quinnat salmon, from its 

 great size and abundance, is more valuable than all other fishes on our Pacific coast 

 together. The blue-back, similar in flesh, but much smaller and less abundant, is worth 

 much more than the combined value of the three remaining species. 



The fall salmon of all species, but especially the dog salmon, ascend streams but a 

 short distance before spawning. They seem to be in great anxiety to find fresh water, 

 and many of them \\OYk their waj uj) little brooks only a few inches deej), where they 

 soon perish miserably, floundering about on the stones. Every stream, of whatever 

 kind, has more or less of these fall salmon. 



It is the prevailing impression that the salmon have some special instinct which 



