176 WONDERS OF POND LIFE. 



cealed until now, are suddenly thrust forward, and 

 seem to revolve as steadily and rapidly as a pulley 

 on the shaft. These two circles of whirling cilia 

 are placed one on each side of the mouth, and 

 move in opposite directions, disturbing the water 

 for some distance in front of the animal, and draw- 

 ing toward it a raft of small diatoms, which it 

 crushes with a mouth that opens and shuts with 

 the regularity of a heart-beat. 



The rotifer is comparatively a highly-organized 

 inhabitant of this museum, and its perfect trans- 

 parency enables one to see the internal structure, 

 such as the alimentary canal, eggs, and the process 

 of digestion. It has eyes, too, though I am forced 

 to believe its vision cannot be very extended, and 

 even with this lens I am unable to discover any 

 gleam of intelligence. 



Drawing the slide a sixteenth of an inch to the 

 left brings us to another region as yet unexplored. 

 Ah ! here is a form stretching its long neck clear 

 across the field, and apparently pecking amongst 

 the spiral vessels which the partly decomposed 

 vegetable reveals. Now it draws in its head, 

 arches its neck and continues to make quick but 

 feeble thrusts at a passing throng of monads. The 

 likeness is so striking that it has been named the 



