82 



DROPS OF WATER. 



are as many genera loricated as illoricated in this 

 class. The Polygastrica are found in all parts of 

 the world, both in fresh and in salt water. 



The first family into which this class is divided 

 is named Monadina, containing creatures of the 

 most minute forms, and only interesting to the 

 unscientific observer on that account; most of the 

 individuals requiring very patient investigation, 

 and high magnifying powers, before their move- 

 ments and habits can be sufficiently understood 

 to be minutely described. It has been discovered, 

 however, that some of the genera possess eyes, and 

 most of them cilia ; some only have a proboscis, 

 and others again a tail ; none are enclosed in a 

 lorica, and they increase by self- division into two 

 or four parts, each becoming a perfect individual. 



