FOR WAGGONER’S BIOLOGY 
59 
a drop of water mounted under the microscope. (Note — By 
mixing a drop of egg white with the drop of water containing the 
paramecia, the movements of the animals may be retarded so as 
to facilitate a study of them.) 
I. Note the shape. Does it seem to be constant? Note the 
fine hairlike structures which cover the body and which move 
rapidly as the animal swims about. These are cilia. Note the 
end which is usually foremost. This is the anterior end. How 
does this end differ from the posterior end? Upon one side of the 
body is a groove. This is the oral groove, which leads just beyond 
the center to the mouth opening. Beyond this opening is a short 
funnel-shaped gullet. The mouth is on the ventral surface. The 
body of the animal consists of protoplasm. This is made up of a 
thick fixed layer, the ectoplasm, and a more fluid granular mass, 
the endoplasm. A thin covering, the pellicle, consists of non- 
hving material. There are two contractile vacuoles. These lie in 
the dorsal region toward either end. Watch them closely. Note 
the radiating canals which surround each vacuole and empty into 
it. Note the food vacuoles which form at the interior end of the 
gullet. In what direction do they move from this position? Make 
a drawing, showing the structures which you have identified. (See 
Waggoner, Fig. 167.) 
If specially prepared stained slides are available, note the large, 
oval, deeply stained mass near the center. This is the macronu¬ 
cleus. In a depression in one side of the macronucleus lies the 
micronucleus, a very small rounded body. 
II. Activities of the Paramecium. When a little powdered 
carmine or (carbon) has been added to the drop of water in which a 
paramecium is present, note how the carmine grains are driven by 
the cilia. Watch grains as they pass down the gullet. Determine 
the process by which food enters the animal. (The grains of car¬ 
mine will enter with the food.) Watch the animal as it swims. Is 
the same side of the body always uppermost? Explain. 
