154 DROPS OF WATER. 



or springing very quickly, not to a great dis- 

 tance, but changing its place, and half turning 

 round at the same time. It has one eye, and a 

 compound rotatory organ, armed with a hooked 

 bristle ; the body is oblong. This is an interest- 

 ing object, and found in the summer, though 

 not very commonly. 



Another leaping animalcule, the Polyarthra 

 trigla (Drop IV. fig. 6), is of very singular con- 

 struction. The body is almost square, and on 

 each side are six strong narrow fins, or bristles, 

 which enable it to swim quickly, or leap sud- 

 denly. It carries its eggs attached to the outside 

 of the body. The small poly gastric animalcule, 

 the CoZacium, mentioned at page 107, is often 

 found infesting both its body and fins, and yet 



