154 



TOWIXG-XET. 



A Towing-net contrived by Dr. Ball for the capture of 

 Crustacea, Acalephce, &c., may be here introduced, as a 

 means of obtaining many most 

 interesting natant animals and 

 vegetables. The diameter of the 

 hoop may be about Jive inches. 

 The net is made of canvas or 

 gauze, in double cones, both ends 

 open. The inner cone prevents 

 the regurgitation of the captives ; 

 the glass tied at the end (an ordi- 

 nary cupping-glass) enables the 

 captor to see what he has caught. 

 He may then untie the string and 

 put the animals away, or he may 

 thrust the glass up through the 

 hole in the inner cone and empty 

 it into his jars. 



In some cases it may be ad- 

 visable to strap some corks round the glass to prevent 

 its sinking when used in a feeble tide-way : the coi'ks 

 may also serve as fenders to prevent the glass being 

 broken against the sides of the vessel. 



At depths beyond which the Laminarise cease to 

 vegetate, that is, from about four to ten fathoms, 

 the bottom of the sea is frequently covered with a 

 vegetation of a very different character, which, indeed, 

 will scarcely be taken, by a hasty observer, to belong to 

 the vegetable kingdom at all. In speaking of Coral- 

 lines in a former chapter, I alluded to a kindred race 

 of vegetables, called Nullipores or Melobesia?, of a stony 



