8G 



were everywhere constant, and where, if those conditions 

 determined the distribution of the fish, one would have 

 expected a similarity of result in the hauls made. These, 

 however, show the most remarkable differences. Haul 6 

 may be left out of consideration as it was longer than 

 Nos. 1 to 5, but in those five hauls the number of plaice 

 caught varies from 14 to 157, of dabs from 8 to 67, and of 

 ray from to 38. The only variable condition is the 

 state of the tide, and there are no apparent regularities 



Port Williain 



Burrow Hd. 



Fig. 4. — Luce Bay, shewing the positions, approximate directions 

 and lengths of the drags. 



to be seen by comparing the catch with this condition. 

 There is no doubt, of course, that the state of the tide did 

 affect the number of fish caught, but the variation in the 

 catches due to this cause is apparently disturbed by 

 variations due to the irregular distribution of the fish on 

 the bottom. 



The same results are given by hauls made by a shrimp 

 trawl on tlie Mersey grounds. The following table gives 

 the result of four hauls made by the same boat during the 



