434 THE MICROSCOPE. 



drift-sand will often be found to contain a wonderful 

 variety of minute spiral univalve shells, though these are 

 scarcely of so small a size as to come within the list of 

 microscopic objects. Others may be obtained by the 

 gatherers of sea-weeds, with little trouble, if they will 

 only preserve the sediment that collects in the water in 

 which the sea- weeds are washed. When the sea- weeds are 

 plunged into fresh water, these minute molluscs (Rissoce) 

 are quickly killed, and fall to the bottom, and may then 

 be secured by simply straining the water through a piece 

 of canvas. Many other minute and curious animals, and 

 sometimes Diatomacece, may be collected in a similar way. 

 " Having thus surveyed the rocks, sands, and weeds of 

 the shore above low- water mark, if we launch upon the 

 deep itself, a similar abundance of minute and interesting 

 forms is still presented to us. A small muslin bag, the 

 mouth of which is kept open by a wire ring about four 

 inches in diameter, towed slowly behind a boat, on a calm 

 and bright day, in any sheltered bay or inlet, will be found 

 to have gathered multitudes of creatures of the most beau- 

 tiful forms, and occasionally of the most brilliant colours, 

 creatures whose crystalline substance affords to our 

 wondering gaze a ready insight into many things con- 

 nected with the structure of the lower animals, which will 

 in vain be sought elsewhere. In this way are collected the 

 numerous species of minute Naked-eye Medusae. Nothing 

 can be conceived more elegant and graceful than the 

 motions of these minute crystalline bodies in a glass of 

 water. On almost every part of the coast, besides the 

 beautiful Tunis neglecta, and the allied Heroes, the towing- 

 net will gather innumerable specimens of a creature 

 resembling a slender spicula of glass, about an inch in 

 length, but which is so slender and transparent as to be 

 almost invisible except in a particular direction of the 

 light: this is the Sagitta bipunctata; and its simple 

 structure affords an excellent subject for microscopic 

 research. When fishing for objects of this kind, it is best 

 to have in the boat a large white basin half filled with sea- 

 water ; and into this the towing-net is to be inverted and 

 gently shaken every now and then. In this way the deli- 

 cate creatures it contains will come out of it without 



