2874 THE BONY FISHES AND GANOIDS 



they would speedily be annihilated; but such is their prolific nature that a remnant 

 always survives to return to the spawning beds and keep up the supply. Buckland 

 calculated that the number of eggs laid by a salmon was about one thousand to the 

 pound weight, a fish of fifteen pounds therefore producing fifteen thousand eggs. 

 The food of the smolt during its sojourn in the sea is abundant, consisting chiefly 

 of sand eels, mollusks, and marine insects. The smolts increase accordingly very 

 rapidly in size, and in three or four months the fish that came down five or six 

 ounces in weight returns to the river from whence it came, a grilse of from four to six 

 pounds; the grilse being the fifth stage of the salmon' s existence. Unless acciden- 

 tally prevented the grilse always returns to the river from whence it came, and after 

 spending the autumn and winter at home, and providing for the continuance of the 

 family by spawning, as already described, returns as a kelt to the sea in the follow- 

 ing year, reappearing the next as a salmon of at least ten or twelve pounds weight.. 

 It should be added, that, after spawning, the fish speedily recover their color, and 

 to a great extent their condition; the baggit at once losing her dark complexion, 

 and the kipper discarding his hideous livery, his great beak being rapidly absorbed, 

 his sides becoming silvery, and his back assuming a dark bluish tinge." 



With reference to the statement in this account that salmon always return to 

 the river of their birth, it may be observed that although this is generally the case, 

 the circumstance that salmon occasionally make their appearance at the mouth of 

 the Thames and other rivers which they have ceased to inhabit, shows that there 

 are exceptions to the rule. The obstacles that salmon will surmount in their ascent 

 of rivers during the return from the sea are too well known to require notice; but it 

 is probable that the height to which they can leap has been exaggerated. The 

 period of spawning varies with the country, taking place in the south of Sweden 

 and North Germany at the latter part of October or early in November; while in 

 Denmark it may be deferred till February or the beginning of March; November 

 and December being the usual spawning months in Scotland. 



In spite of their diversity of habitat, and likewise of coloration and 

 structure, Day is of opinion that the migratory sea trout, or salmon 

 trout (S. trutta), and the stationary river trout (S. farid}, as well as the various 

 forms from the British lakes, are nothing more than varieties of a single variable 

 race; and it must be confessed that no one has hitherto been able to define all the 

 nominal British species with anything like definiteness. Still, however, in the 

 modern sense of the words there is no possibility of drawing a hard-and-fast line 

 between a species and a variety; and the question is accordingly of no very great 

 importance one way or another. Some of the characteristics distinguishing the 

 salmon from the trout have been already indicated on p. 2868; and it will suffice to 

 note very shortly some of the reasons given by Day for regarding all the British 

 trout as referable to a single species. It is well known that sea trout as rep- 

 resented not only by the typical form, but likewise by the so-called sewen (S. cam- 

 bricus} of the Welsh rivers are silvery in color, with black spots during their 

 sojourn in the sea; when, however, they enter the rivers for the purpose of spawn- 

 ing, an orange margin appears on the upper and lower edges of the caudal, and 

 likewise on the fatty, fin; while spots of the same color show themselves on the 



