PROTOZOANS. 



How TO Find Them. — Protozoans, may be obtained in 

 large quantities by any of the following methods : 



(i) In a vessel boil some dry hay in water. Pour con- 

 tents of vessel into a jar and allow it to cool. Into this 

 infusion put some fresh hay. Amoebae will appear in two 

 or three days. 



(2) Take a pond lily or other water plant from the 

 water of a pond or pool and put it in water allowing it 

 to remain a week or more, until the plants are partially 

 decayed. This water will generally contain a cilliate infus- 

 orian, Paramecium. It will also often contain many other 

 genera of protozoans. 



(3) Scrape the slimy mud in the bottom of a pond or 

 pool and place it in a bottle or tumbler with several inches 

 of water on it. Allow it to stand for several days in a dark, 

 warm place, and pour into it occasionally a little fresh 

 water. Many different kinds of Protozoans will generally 

 be found in this and it will often contain amoebae, and some- 

 times Cyclops (a crustacean), and larval luollusks. Proto- 

 zoans may generally be distinguished by a flattened form and 

 the lack of definite appendages. 



How TO Study Them. — With a pipette, or medicine 



106 



