THE PEOTEtrS ANIMALCULE 9 



the movements or pulsations of the contractile 

 vacuole. How frequent are they ? Are they reg- 

 ular ? By what do they seem to be produced ? 

 What becomes of the contents of the vacuole 

 during a contraction ? Do the contractions affect 

 the granules in the endosarc ? What do you take 

 to be the function of the contractile vacuole ? Is 

 it possible that it serves more than one function ? 



h. Nutrition. — What does the animal eat? How does 

 it obtain its food ? How is the food taken 

 into the body? Grind a small piece of indigo 

 or of carmine in water, mix a drop with that on 

 the slide, and watch to see Amwha ingest the 

 particles. JSTote, also, the movement of these 

 particles around through the body mass. Where 

 is the mouth? In what part of the body is 

 the food digested ? Why does not Amoeba di- 

 gest itself ? How is the digested food distributed 

 to different parts of the body ? Where does the 

 waste matter leave the body ? In what manner 

 does the animal breathe ? What breathing or- 

 gans does it have ? Where are they situated ? 



c. Sensation. — If the specimens be large the cover-glass 

 may be carefully removed, or a fresh specimen 

 prepared without the cover, and, while examin- 

 ing with a low power, the animal may be care- 

 fully touched with the point of a fine bristle. 

 Does Amaeba give any indication that it feels 

 such an irritation ? Tap the slide with a pencil. 

 How does the animal behave? Put a covered 

 preparation on the warm stage, and heat slowly 

 to about 45° C. What visible changes take place 

 in the animal? With another covered specimen 



