66 FRESH-WATER BIOLOGY 



near its middle by a wire and is lowered to the bottom at any 

 depth by a cord supported by a float. It is used chiefly for smaller 

 fish, crayfish, or Necturus. It may be set anywhere but is espe- 

 cially useful where water is obstructed by vegetation, rocks, or 

 fallen trees so that nets cannot be drawn. 



(/) Care of nets. Both fyke nets and gill nets should be taken 

 from the water at intervals, washed, dried, and mended before they 

 are again used. For mending it is necessary to have a supply of 

 twine of which the nets are made and several wooden shuttles or 

 needles such as fishermen use; it is also necessary to learn the 

 knot used in making nets by hand. All nets when taken from 

 the water should be washed and carefully dried before being put 

 away. If left with the twine clogged with accumulated organic 

 matter they rapidly decay and this decay is the more rapid if the 

 nets are damp. They may be stored by hanging them loosely in 

 some dry loft or they may be packed in bags and hung from the 

 ceiling by cords. If left accessible to rats or mice they may be 

 ruined by being utilized as nest material. 



In laying a net for storage or transportation the lead and cork 

 lines should each be folded back and forth on itself. The lead 

 line should be so folded that the leads are brought together and 

 they should then be securely tied together. If this precaution is 

 not taken the loose leads, carrying the lead line with them, become 

 woven back and forth through the net and the whole is almost 

 inextricably tangled together. 



2. Turtles. Turtles are best taken in a turtle net which is a form 

 of fyke net. It should be of heavy twine and coarse mesh and, if it 

 is desired to keep the turtles alive, should be modified as follows: 

 The terminal section of the pot is made cylindrical or the whole 

 pot may be made with square hoops. A circular opening is cut in 

 the upper side of the terminal section of the pot and to this is 

 attached the lower end of a cylinder of netting which extends to 

 the water's surface. The upper end of this cylinder is attached to 

 an opening cut in one side of a wooden box provided on the oppo- 

 site side with a hinged lid fastened with a hasp. The box is sup- 

 ported at the surface of the water on poles set in the bottom. 

 When turtles reach the terminal section of the pot they are able 



