PEOPAGATION AND GROWTH OF HEERING. 641 



ing, and when spawning in fiords and sounds generally keeps near the 

 land. The choice between neighboring spawning- places often depends 

 upon the weather, and it has several times been observed that violent 

 and continued storms have compelled the herrings to spawn at some 

 distance from the coast in places which otherwise were not suitable ; as 

 likewise, that in too cold or too warm weather they seek deeper spawn- 

 ing-places, for even jirior to spawning they prefer an even temperature. 

 According to Wcstrom, they also prefer places where there is a current."^ 

 It has also been observed that the older and larger herrings prefer those 

 spawning-places which are near to the open sea, whilst the smaller and 

 younger ones go nearer the coast or higher up the fiords. 



Besides those herrings which regularly spawn at or near the coast, 

 there seem to be some which generally spawn in the open sea on banks 

 suitable for the purpose, located at a sufficient depth to afford pro- 

 tection against any violent commotion of the waves; and it is an old 

 conjecture, that those herriugs which during long periods have in large 

 numbers visited the western coasts of Scandinavia for the puri)ose of 

 spawning, during the intervals visit such banks in the North Sea.^ As 

 those portions of the eastern Skagerack near the cost of Bohuslan which 

 are suitable for spawning are limited in extent, are not very well pro- 

 tected, and are generally found to have a comparatively small depth, it will 

 easily be understood why they have not become permanent spawning- 

 places. The supposition that a large race of herrings spawns there 

 regularly every year is therefore not in accordance with the actual facts. 



Regarding the depth in which the herrings spawn it seems that they 

 generally prefer a depth of a few fathoms ; more recent observations 

 have proved, however, that occasionally they may spawn at a very con- 

 siderable depth (GO to 100 fathoms), and that the eggs may be hatched 

 there. It is not certain, however, that such a depth is favorable to the 

 raising of the young flsh.^^ Along the coast of Bohuslan there are prob- 

 ably few spawning-places deeper than 10 to 15 fathoms^'^, most of them, 

 especially those higher up the fiords, being only 2 to 5 fathoms deep. 



It has long been known and has been mentioned among others by 

 Pennant and Nacl de la Morimere^ that considerable quantities of fish- 

 eggs are found floating near the surface of the open sea ; the Dutch fish- 

 ermen even believe that most of the herrings are raised from such float- 

 ing masses of fish-eggs ("herring-beds"); but, as we shall endeavor to 

 prove, this cannot be the case, as the eggs of the herring are heavier 

 than water and can therefore not float on the surface. In order that 

 the eggs may be fastened to suitable objects, the spawning process 

 should go on near the bottom, and these so-caUed "herring-beds" owe 



'' Die Fische in den Scheeren von Morko. Berlin, 1835, pp. 216, 22a. 



8A. BOECK, "Om Silden og SildefisJcerierne." I. Christiania, 1871, pp. 128-I2d.—Tidsslcrift 

 for FiskerL VII, p. 'id.—Nordish Tidsshrift for Fiskeri. II, p. 263-264. 



I'H. Kroyer, " Danmarks Fiske." III. Copeuhageu, 1846, p. 163. 



i^They are nearly all located near the northern portion of the coast, especially from 

 the Vader Islands to Koster. 

 41 F 



