WHEELr-BEARERS 261 



rated or brought into contact, at pleasure. By means of 

 these the animal has the power of mooring itself, even 

 to the smooth surface of glass; and that so firmly that 

 from them it can stretch itself in all directions by 

 turns, now and then shaking itself to and fro with 

 sudden violence, as if irritated, yet without letting go 

 its foothold. 



While thus anchored, the action of the ciliary wheels 

 produces considerable whirlpools in the surrounding water, 

 as you will see very distinctly when we have recourse to 

 a curious but simple expedient, first invented by Gleichen 

 and since much used by Ehrenberg, of mixing some color- 

 ing matter with the water in which the animal is. I take 

 a little carmine with a wetted hair-pencil, as if I were go- 

 ing to color a drawing, and allow a small portion of the 

 pigment to diffuse itself in the water which is in the live- 

 box, then, putting on the cover, I quickly replace the 

 whole on the stage, and refind my little Brachion: and 

 now I again submit it to your observation. 



The whole field is now filled with scattered granules 

 of irregular form and size, of a dark-red hue. These are 

 the particles of carmine floating in the water; particles of 

 alumina, that is to say, stained with cochineal. They are 

 in motion, and their movement is more energetic the 

 nearer they are to the little animal, which is rotating 

 vigorously in the midst of them. They describe two 

 great circles, concentrical with the two wheels of the 

 Brachionus, and it is easy to see that their rotations 

 are the cause of the movement. The motion of the cilia 

 communicates itself to the surrounding water, and pro- 

 duces circular currents, into which every floating atom 

 within a certain distance is drawn, and in which it then 



