THE ROMANCE OF NATURAL HISTORY. 



had been altogether overlooked and unsus- 

 pected. 



What is more interesting than an examination, 

 by means of a first-rate microscope, of a tiny 

 atom, that inhabits almost every clear ditch, — the 

 Melicerta? The smallest point that you could 

 make with the finest steel-pen would be too coarse 

 and large to represent its natural dimensions ; yet 

 it inhabits a snug little house of its own construc- 

 tion, which it has built up stone by stone, cement- 

 ing each with perfect symmetry, and with all the 

 skill of an accomplished mason, as it proceeded. 

 It collects the material for its mortar, and mingles 

 it; it collects the material for its bricks, and 

 moulds them; and this with a precision only 

 equalled by the skill with which it lays them when 

 they are made. As might be supposed, with such 

 duties to perform, the little animal is furnished 

 with an apparatus quite unique, a set of ma- 

 chinery, to which, if we searched through the 

 whole range of beasts, birds, reptiles, and fishes, 

 and then, by way of supplement, examined the 

 five hundred thousand species of insects to boot, — 

 we should find no parallel. 



The whole apparatus is exquisitely beautiful. 

 The head of the pellucid and colourless animal 

 unfolds into a broad transparent disk, the edge of 

 which is moulded into four rounded segments, not 

 unlike the flower of the heart' s-ease, supposing the 

 fifth petal to be obsolete. The entire margin of 

 this flower-like disk is set with fine vibratile cilia, 

 the current produced by which runs uniformly in 

 one direction. Thus there is a strong and rapid 

 set of water around the edge of the disk, follow- 

 ing all its irregularities of outline, and carrying 

 with it the floating particles of matter, which are 

 drawn into the stream. At every circumvolution 

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