62 DEEP-SEA FISHING. 



called the "flapper,"^ fastened to the upper part or 

 back, and with its free edge directed towards the cod, 

 so that the fish can easily make their way under it into 

 that part of the net, but cannot so readily return. The 

 mouths of the pockets face and open into the cod or end 

 of the net where the fish are collected, and there being 

 no means of escape for the fish at the cod-end, many of 

 them, and especially the soles, work their way along 

 the sides of the cod into the pockets, continuing their 

 progress in that direction till they are stopped by the 

 gradual narrowing and termination of these long 

 funnel-shaped enclosures. 



It does not appear very difficult to understand why 

 soles especially should generally be found in the pockets 

 of a trawl. Soles are naturally quiet fish, and bury 

 themselves more completely than any of the other kinds 

 which keep on the ground, excepting perhaps some of 

 the rays. In an aquarium they will remain for hours 

 in the same place during the day, and so much covered 

 by the sand as to make it often difficult to discover 

 them. Their general feeding time is at night, and then 

 of course they are more on the move and out of the 

 ground, which will explain what the trawlers have long 

 since found out by experience, namely, that heavier 

 catches of these fish are always made by night than by 

 day fishing, except sometimes in very deep water. But 

 when soles are disturbed, their first impulse is to hide 

 themselves in the sand after darting a very short dis- 

 tance from the place where they were lying. Having 

 once crossed the ground-rope of the trawl, however, and 

 entered the net, they cannot bury themselves, because 

 the net is between them and the ground ; moreover, it 

 is constantly dragging over tlic bottom as the trawl 



^ The position of tlic flapper is marked by a dotted line in Fig. 1. 



