238 USE OF THE TOW-NET. 



the net may move gently through the water, so as to avoid crushing 

 its soft contents against its sides. Those of firmer structure (such 

 as the Entomostraca), on the other hand, may be obtained by the 

 use of a Tow-Net attached to the stern of a sailing-vessel or even 

 of a steamer in much more rapid motion. When this method is 

 employed, it will be found advantageous to make the net of 

 conical form, and to attach to its deepest part a wide-mouthed 

 bottle, which may be prevented from sinking too deeply by 

 suspending it from a cork float ; into this bottle many of the 

 minute Animals caught by the net will be carried by the current 

 produced by the motion of the vessel through the water, and they 

 will be thus removed from liability to injury. It will also be useful 

 to attach to the ring an inner net, the cone of which, more obtuse 

 than that of the outer, is cut off at some little distance from the apex ; 

 this serves as a kind of valve, to prevent objects once caught from 

 being washed out again. * The net is to be drawn-in from time to 

 time, and the bottle to be thrust-up through the hole in the inner 

 cone ; and its contents being transferred to a screw-capped bottle 

 for examination, the net may be again immersed. This form of net, 

 however, is less suitable for the most delicate objects than the simple 

 Stick-Net used in the manner just described. — The Microscopist on 

 a visit to the sea side, who prefers a quiet row in tranquil waters 

 to the trouble (and occasional malaise) of dredging, will find in the 

 collection of floating Animals by the careful use of the Stick-Net 

 or Tow-Net a never-ending source of interesting occupation. 



* This form of Tow-Net may be obtained from Mr. Highley. 



