THE INVISIBLE WORLD REVEALED. 9 



tration; for example — from some water containing 

 aquatic plants, collected from a pond on Clapham Com- 

 mon, I select a small twig, to which are attached a few 

 delicate flakes, apparently of slime or jelly; some 

 minute fibres, standing erect here and there on the 

 twig, are also dimly visible to the naked eye. This twig, 

 with a drop or two of the water, we will put between 

 two thin plates of glass, and place under the field of 

 view of a microscope, having lenses that magnify the 

 image of an object 200 times in linear dimensions*. 

 Upon looking through the instrument, we find the fluid 

 swarming with animals of various shapes and magnitudes. 

 Some are darting through the water with great rapidity, 

 while others are pursuing and devouring creatures more 

 infinitesimal than themselves. Many are attached to the 

 twig by long delicate threads, (the Vorticellce, pi. iii, 

 fig. 3); several have their bodies inclosed in a trans- 

 parent tube, from one end of which the animal partly 

 protrudes and then recedes, (the Floscularice, pi. vii); 

 while numbers are covered by an elegant shell or case, 

 (the Brachionus, pi. xii, figs. 1, 2). The minutest 

 kinds, (the Monads, pi. ii, figs. 1, 6), many of wliich 

 are so small that millions might be contained in a single 



"Patchwork," by Captain Basil Hall, Vol. iii, p. 13. — London, J^-r'j:^--~>^ 

 Moxon, Dover Street, 1841. /~C\<^-^~^ L y 



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* This is equal to 40,000 times in superficial dimension. 



