374 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



grounds, and even if these were caught while still imma- 

 ture fishes frequenting territorial waters there would still 

 be a net gain. It is a question worthy of consideration 

 therefore whether, in the interests of the Plaice fishery, 

 some restrictive measures applied to methods of shrimp 

 fishing would not be of benefit to the whole fishing 

 industry. 



We are referring here to the method of fishing for 

 shrimps with the shrimp trawl, which is a net of the 

 pattern of the larger fish trawl described above but with 

 a mesh of 2 inches in periphery. Other forms of shrimp 

 nets are used, particularly the " shank " net, which is a 

 net like a trawl but having the beam, foot rope and irons 

 replaced by a rectangular wooden frame. A further 

 improvement consists in attaching the lower edge of the 

 net, not to the lower bar which drags on the ground, but 

 to another bar, parallel to this but placed two or three 

 inches above it. When disturbed the shrimp jumps, and, 

 clearing the bar, enters the net, while the fish when dis- 

 turbed swims off close to the ground and may escape 

 through the space between the two bars. Experiments 

 have shewn that these two nets capture relatively less 

 fishes and more shrimps than the ordinary shrimp trawl. 



We have yet to refer to the artificial incubation of 

 Plaice eggs as a means of recruiting a fishing area in 

 process of exhaustion by overfishing. So far this has only 

 been extensively practised in Scotland. Mature male and 

 female Plaice are captured some time before spawning 

 begins and are penned in a " spawning pond." Spawning 

 and fertilization take place in the pond as in the sea and 

 the fertilized eggs are collected daily and are put into 

 the " hatching boxes." Through these a constant stream 

 of sea water passes and they are kept in continual motion 

 to avoid the clustering of the eggs and the risk of insuffi- 



