166 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



95 per liaul; the average for the seven years (1893-99) 

 was nearly 567 per haul. 



(4.) The number of fish caught on closely-adjacent 

 grounds is sometimes very different, even when the 

 depth and bottom are very similar. Caution is, therefore, 

 necessary in comparing neighbouring grounds, even when 

 these are similar physically, unless we have previously 

 ascertained that they are almost similar oiologically. 



(5.) Our statistics for the 10 years 1893-1902 show 

 that : — 



1. Young plaice on the shrimping grounds have 



diminished. 



2. Young soles on the shrimping grounds have 



increased. 



The distribution and relative abundance of these 

 young food fishes throughout the year on the various 

 banks and other shrimping grounds will have to be still 

 further studied from more abundant statistics before 

 these variations can be considered as established and 

 understood. 



In regard to the shrimp, also, we want more informa- 

 tion as to the relative abundance of the sexes, the 

 spawning periods, the time of hatching, the rate of 

 growth, the proportional numbers throughout the year, 

 and the distribution on and about the shrimping grounds. 

 It must be remembered that work done in other seas 

 cannot be utilised in our own district except as a general 

 guide to investigation. An intensive study of the fish 

 and shrimp populations on the areas we propose to deal 

 with will have to be undertaken. 



Such investigations as we contemplate would require 

 one whole daj^'s trawling per week on each of the prin- 

 cipal grounds to be compared, say in Morecambe Bay, on 



