132 AQUATIC MICROSCOPY FOR BEGINNERS. 



■ CHAPTER V. 



infus6ria. 



The reader probably knows the infusoria under the 

 name of animalcules, a word meaning small animals, 

 which the Infusoria certainly are. But a mouse is a 

 small animal; so is a Water- flea (Chapter X.) and a 

 Rotifer (Chapter VIII. ). Infusorium for a single, one 

 of a group of certain microscopic creatures, and In- 

 fusoria as the plural, are better words than animalcule, 

 with no danger of conveying an incorrect meaning. 



The Infusoria were so named because they were 

 first discovered in infusions, that is, water in which 

 animal or vegetable substances had been soaking and 

 decaying. Since that time the creatures have been 

 obtained in great abundance and variety in even the 

 sweetest of fresh waters, although they abound in as- 

 tonishing numbers in many infusions. The reader has 

 only to place a handful of hay in a tumbler of water, 

 and allow it to soak for a week or two, or even for 

 only a few days,- when he will have as many Infusoria 

 as he may want for examination. They are also plen- 

 tiful in every ditch and pool of still water. No collec- 

 tion of Algse, aquatic plants, or Rhizopods, can be 

 made without, at the same time, gathering many In- 

 fusoria. 



