and prices are based on the capture of living plaice, especially when the 

 fish are caught in nets wbich stand for many hours (not in seines), in accordance 

 with the bye-laws of the Limfjord for the greater part of tlie year. In the case 

 of tlie trawls, whieh are quickly drawn up, the whelks do not get time to attack 

 the plaice; but the trawl has other drawbacks, which, however, need not be further 

 discussed on this occasion. 



The whelks find the plaice and their food on the whole by means of their 

 linely developed seuse of smell. They also attack all other fishes fixed in the nets; 

 in a few hours 10—20 whelks will often fix themselves on to a plaice or other 

 dead fish on the bottora of the sea. The whelks are so uumerous, that some 



Fig. 2. 



hundreds, both large and small, can be fished in 24 hours in a hivetrap with 

 a piece of split cod as bait. We may imagine, that in the centre of the Limfjord 

 several whelks occur on an area no larger thau the floor of a room; as they are 

 able to crawl rather rapidly, we can understand how, in the course of a few hours, 

 they might easily find a dead fish lying on the bottom and devour the muscles. 

 On the other hånd, they will not touch rotten fish; experiments with soiled bait 

 in the hive-traps have clearly proved this. Sometimes dead fishes can be found 

 in numbers on the bottom of the Limfjord; this was the case in 1909 in the spring, 

 when a great number of eels had been frozen dead in the wiuter; they were rotten 

 before the whelks had any desire to feed, but I have never seen auythiug similar 

 in the summer; everything eatable which siuks to the bottom is evideutlj' quickly 

 devoured at that season. 



It is very difficult to find out, how great is the number of net-entangled 

 plaice which are devoured by the whelks throughout the year, as this depends on 

 so many circumstances. For example, it is especially in tlie warmest summer 



