312 ZOOLOGY. 



teeth,* which occur so rapidly in the same individual that the novice might readily be par- 

 doned for supposing — Rafinesque-like — an indefinite series of new genera and species. 



The idea that most of the species now recognized are simply varieties of one or two kinds is 

 equally preposterous, as shown by making careful anatomical comparisons between individuals 

 of different species, thus showing constant distinctions when compared at corresponding seasons. 

 In some species the "hooked-snout" is peculiar to the males when fresh-run and in good order. 

 In others this feature is only recognized as a mark of exhaustion or of age, and occurs in both 

 sexes. Alterations in color have been frequently spoken of in this report. Some idea may be 

 gained of these by examining Agassiz's plates of similar changes in the European S. salar. 

 Besides the differences in the changes noticed between one species and another, are those 

 between the two sexes of the same species. This, in the case of the salmon seen by me spawning 

 in Burnt river, was very well marked. — (See beyond.) In describing the colors of a species 

 under the head of specijic characters, none but those of the "fresh-run" adult should be 

 entered. Additional confusion in our books has been produced by the carelessness of explorers 

 in this respect. An example of this appears to be in the colors assigned to salmo ClarJcii by 

 Dr. Gairdner; but, as they have evidently been described from an exhausted fish, or one at 

 jeast partially so, I confess my inability to identify the species with certainty. — (See remarks 

 under the head of Salmo clarkii.) 



Several of the autumnal salmon are of a dingy color, even when in good order and fresh from 

 the sea. Their flesh is light colored and of poor flavor, and some are so rank as to be positively 

 disagreeable. If ever silvery, it must be when in the sea, long before instinct has sent them 

 to the rivers to attend to their reproductive duties. If that is the case, it would seem that the 

 change -n color is as much owing to a disturbed condition of the system, produced by sexual 

 commotion, as to emaciation and fatigue. 



All species — the trout less so than the others — go through these changes of color after 

 remaining a short time in fresh water; the changes being most noticeable as the fish is becoming 

 rapidly exhausted. The bright silvery species lose their glistening appearance, the blue and 

 lead colors of the back become green or dingy olive, and the silvery white of the sides and 

 belly blotched with patches of dark olive, alternating with purplish maculations. 



These purplish discolorations, or rather colorations, frequently change into deep red. and 

 sometimes into lake, the fins especially showing the red. It might seem that this intermixture 

 of red would indicate an activity of the circulation. This is not the case, but seems to be the 

 result of a stagnation of the blood in the superficial capillaries, and another evidence of the 

 broken down scorbutic condition of the impoverished fish.t 



The salmon are said not to eat after their entrance into fresh water; notwithstanding this, 

 they have to undergo the exhaustion consequent upon their exertions in ascending the rivers, 

 jumping water-falls, and stemming currents, which, superadded to the debility necessarily 

 produced by the process of spawning, sufficiently accounts for their impoverished condition 

 during and after spawning season. Indeed, hosts upon hosts do not survive, but die after 

 completing their instinctive duty, and often before. Some of the shores of the small lakes and 

 tributaries of the Columbia are said to be lined with the dead and dying fish in autumn. 

 Salmon that enter the Columbia ascend the principal river as high as the lakes on its course 



° The wasting of the flesh and consequent absorption of the fat of the fish, causes the gums to shrink from the teeth and 

 the nose to assumed a hooked form. The teeth thus exposed look much larger than before. 

 t See remarks under the head of 5- paucidens. 



