196 EVENINGS AT THE MICROSCOPE. 



we lately examined. They maintain a vivacious motion,, 

 and yet at the same time keep their association and the 

 general form of the column. 



Taking out a few of the dancing atoms, and isolating 

 them in this glass stage-cell, we see that they have exactly 

 the figure, appearance, and character of the young of the 

 common Cyclops ; so that you would, without hesitation, 

 if you knew nothing of their parentage, assign them to 

 that well-known genus. Their movements are almost 

 incessant ; a series of jerking progressions, performed 

 by quick but apparently laborious flappings of the limbs, 

 right and left together. They occasionally rest from 

 their exertions for a few moments, but seem to have no- 

 power of alighting on any object. 



But, in order to obtain a more precise idea of the 

 structure of this tiny creature, we must manage to re- 

 strain its liberty a little, by applying gentle pressure 

 with the compressorium ; just sufficient to confine it 

 without hurting it. The body is inclosed in a broad 

 carapace, shaped much like a heraldic shield, but very 

 convex on the back, and terminating behind in a slender 

 point or spine, which is cut into minute teeth along the 

 edges. Below this shield is seen the body, with three 

 pairs of legs, a great proboscis in the middle pointing 

 downwards and backwards, and the anal fork, which 

 consists of a bulbous base and two diverging points^ 

 which project behind under the spine of the shield. 



The legs are exclusively swimming organs: they have 

 no provision for grasping, no claws or hooks, nor do they 

 appear to be capable of being used for crawling on the 

 ground, or for climbing among the sea- weeds. They are 

 fringed along one edge with long and stout, but somewhat 

 flexible, spines, of which those that are nearest the trunk 

 seem more rigid, and are directed more at right angles to 

 the limb, than the rest. The legs are formed of many 

 imperfect joints, and the second and third pairs are- 



