THE SALT-WATER FISHERIES OF BOHUSLAN. 213 



numberless marine animals, and by their consuming a large quantity of 

 food. This change may fmnllj- become so marked as to make these 

 waters unfit for spawning, at least for a large race of herrings. The only, 

 and nearly always sufficient, protection of the herring in its combat for 

 existence is its fecundity; and although we must acknowledge, with 

 Kroyer, that " danger does not put the herrings to flight, and that noise 

 does not scare them away, but that their instinct points out the way they 

 have to follow," this very instinct would naturally lead them to leave 

 spawning-places which are no longer fit for spawning and seek new ones. 

 It will therefore be clear that in proportion as the extent and nature of 

 the spawning-])laces no longer correspond witli the size of the race of 

 herrings, the influence of this size will make itself more and more felt, 

 and produce a change of time and place in the fisheries. 



In order to judge the probability of this theory it will be necessary to 

 find out how the above-mentioned regular changes of time and place of 

 the herrings' visits to the coast can be explained by it. When a large 

 race of herrings is compelled to seek another and distant spawning-place 

 (in the case of Bohuslan, a more easterly one), they will, in consequence, 

 come later in the year; but if they extend their "hunting-excursions" 

 so as to come a little nearer, or the spawning in a still undisturbed 

 spawning-place occupies less time, they may come earlier, and after hav- 

 ing spawned, return earlier to their former district. Thus the herrings 

 would gradually come earlier and extend their visits to other parts of 

 the coast (in Bohuslan farther south) until they have brought their " hunt- 

 ing-district " as near the coast as i^ossible. As this was really the case, 

 and as the farthest spawning-places (in Bohuslan those on the southern 

 coast) were disturbed, the herrings were compelled to seek their spawn- 

 ing-places nearer and nearer to the point where they first approached 

 the coast (in Bohuslan farther north). The search for spawning-places 

 took up some time; the herrings consequently came later and also left 

 the coast later. They therefore also arrived later at their "hunting- 

 grounds," and left the grounds later for the purpose of spawning. In 

 proportion as they reached the "hunting-grounds" later, they would 

 have to advance farther (that is, farther nortli) into these, because they 

 would arrive in a more starved condition, and therefore require more 

 food, which could only be obtained by scouring through a larger extent 

 of water. The circumstance that during the last great Bohuslan fishery- 

 period the herrings irregularly visited the southern, central, and northern 

 coast, is easily explained by the fact that they did not come to the coast 

 for the purpose of spawning, and that they always waited for some time 

 outside the coast before coming nearer. 



61. This theory of the successive disturbance of the spawning-places 

 may possibly also explain the more incomplete periodicity which, as an 

 experienced fisherman informed me, is noticed in the Sound and in the 

 Great Belt, where the herrings seem to alternate between eastern and 

 western spawning-places, so that one year there is good fishing in the 



