WHEEIs-BEARERS 



beat and resumed the erect position, three or four others 

 are in various degrees of flexion, regularly graduated; 

 and that if the eye could look laterally at such a row 

 of cilia suddenly arrested and fixed as they were, we 

 should see their tips tracing a wavy line instead of a 

 straight one. Moreover, since the bending of any cilium 

 brings its tip nearer to its successor than it was before, 

 and this approximation increases the further the flexure 

 proceeds, it follows that at the bottom of each wave the 

 tips of the cilia overlap their successors, while the spaces 

 perpendicularly above their bases are left more open by 

 the removal of their points. 



Hence, in microscopical observation of ciliated ani- 

 mals, though the individual cilia are too minute to be 

 discerned while still, we can readily discern the increased 

 density (and therefore opacity) of the bottom of a wave, 

 contrasted with the increased openness (and therefore 

 clearness) of the summit. So that the optical effect is 

 that of an alternate succession of dark and light spots 

 blending into each other. 



But as no cilium in the series is for two successive 

 moments in the same degree of flexure, and as both it 

 and all its predecessors and successors are ever urging 

 on their perfectly timed and regulated course, the waves 

 are never fixed, but always gliding on with a swift but 

 beautifully even rapidity. And as it is with the waves, 

 so it is with their optical effect upon the eye; the black 

 and white spots, or rather the black spots with blank in- 

 tervals, appear to be constantly chasing each other in 

 ceaseless race. 



You are then prepared to take a peep at this beautiful 

 Brachionus pala. A cup of elegant form, swelling at the 



