652 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



means my opinion that all the herrings which spawn on the coasts of 

 !Northern Europe come from the above-mentioned part of the ocean. 

 There are doubtless different tribes of herring ; this seems to be espe- 

 cially the case in the more inclosed portions of the sea, although I am 

 inclined to think that the number of these tribes has been greatly over- 

 rated. The northern and southern part of the Baltic has certainly each 

 its own tribe, likewise the Kattegat, and partly the Skagerak and the 

 North Sea. lam also of opinion that the Nordland great herring be- 

 longs to a special tribe, whose place of sojourn is farther north than 

 that of the spring-herring, viz, in the Polar Sea. But those schools of 

 herring which are referred to in this report which spawn on our western 

 coast, from the ledges of Christianssund to those of Stavanger, I cer- 

 tainly consider as belonging to one and the same large tribe; and this 

 opinion is confirmed by the fact that even the most experienced fi.sher- 

 men are not able to point out any real difference between the spring- 

 herrings found at different points along this coast. 



The chief difference between my theory and the one generally enter- 

 tained in former times is this, that the various tribes of herrings are 

 not limited in their occurrence to certain deep basins near that coast 

 ■where they spawn, but that they are found all over the adjoining sea, 

 since the herring, either singly or gathered in large and smaller schools, 

 roam about from place to place more or less near the surface of the 

 water in search of its food, which is the same as that which it uses when 

 younger (as summer herring). It is evident that this leads us to the 

 conclusion that the spring herring is much less stationary in its mode 

 of life than might have been supposed according to the former theory, 

 and that many physical conditions of the sea (direction of the current, 

 occnrrence of food, temperature, &c.) exercise a very important influence 

 on the distribution of the herrings, so that, e. g., the chief mass of them 

 will one year at a given time be found either nearer to or farther from 

 the places where they spawn. This point is, in my opinion, of great im- 

 portance, as I think I can thereby explain in a natural manner the irreg- 

 ularity in the spring-herring fisheries on our western coasts, which have 

 been observed for a long time, and which have been called " herring 

 periods." I shall have occasion to return to this i)oint, and I will here 

 briefly give my idei concerning the mode of life and the migrations of 

 the herring from the time it is hatched till as fully-matured spring-her- 

 ring it returns to the coast where it has first seen the light of the world, 

 basing my views on observations made by me during this and the pre- 

 ceding year. 



The young of the spring-herring, according to A. Boeck's observations 

 (Om. Silden, &c.., p. 14, 15), spend the first period of their existence 

 near the bottom in those places where they have been hatched, therefore 

 chiefly on the raised bottoms near the outer coast, where the spring- 

 herrings generally spawn. As soon as the umbilical bag has been com- 

 pletely absorbed and the fins have developed, making the movements 



