20(3 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



" herring-mountain," — a high, deep, and closely-packed mass of herrings. 

 It has been found, by certain observations which have already been 

 communicated in Boeck's well-known work on the herring, (p. 47,) that 

 the herring always comes from the northwest. That it follows this direc- 

 tion is easily explained by the fact, settled by Professor Mohn's meteo- 

 rological observations, that the sea on this portion of the western coast 

 of Norway, during the winter-months, (December to February,) has a 

 higher average degree of warmth than near the coast farther south, or 

 on the coast a little to the north, a very uniform degree of warmth, (5° 

 to G° Eeaumur,) about the same as in the nearest portion of the sea- 

 basin from which the herring is supposed to come. If the herring would 

 go due east, therefore, to a more northerly portion of the coast, e. //., the 

 neighborhood of Throndhjem, it would come in contact with water whose 

 degree of warmth would decrease very rapidly toward the north, from 

 4° to 2° Eeaumur. Another school of herrings, the Nordland great-her- 

 ring, lives, in Sars's opinion, to the northwest of Nordland and Fin- 

 marken, but somewhat nearer the coast, because there the sea is richer 

 in small crustaceans than farther south, in the neighborhood of the 

 coast ; it, therefore, comes near the coast comparatively early in its 

 migration toward the southeast or south, being fatter, but less ready to 

 spawn. 



Immediately after being hatched, the young herring, being born on 

 the bottom of the sea, naturally stays near it on the outer coast, where 

 the spring-herring loves to spawn. As soon as the umbilical bag has 

 been completely absorbed and the fins have become developed, it goes 

 near the surface of the water to snap for small living animals; but as 

 near the outer coast it is exposed to many dangers, (the current, heavy 

 waves, &c.,) and to the persecutions of birds and fishes, instinct has 

 taught it to go nearer to the land, in the more secluded sounds and bays, 

 where it often can be seen in enormous numbers. As soon as it has 

 reached the size of a few inches, it begins to rove about in constantly- 

 increasing schools, in fact to assume its — according to Sars — charac- 

 teristic roving mode of life, which is again dependent on its food, 

 viz, the small crustaceans of the surface, whose very irregular occur- 

 rence is again dependent on the current. It also depends on acci- 

 dental circumstances how far it goes from its birth-place during this 

 first period of its life, and to what extent it scatters over a larger 

 or smaller portion of the coast. During its first year, however, it 

 probably keeps near the coast; only gradually as it grows larger and 

 its desire for food increases will it be obliged to go farther out into 

 the sea, where the small crustaceans, as a general rule, are found in 

 great quantities, and thus, like the torsk, it gradually approaches those 

 portions of the sea where its ancestors came from. All this would 

 go on with the greatest regularity, if the small crustaceans were not 

 frequently packed together, by sudden changes in the weather and con- 

 sequent changes of the current, in large masses near the coast and its 



