PARAMECIUM 59 



so produced seems to serve as something of a protection to 

 Paramecium. 



Within the entoplasm are food vacuoles, masses of food 

 forming little spheres or globules and surrounded by a little 

 liquid. Are these of the same size? Where in the body 

 are they most abundant? Do they resemble the food 

 vacuoles of amreba? Do you find contractile vacuoles? 

 How many? Where situated? Is the contraction or the 

 expansion more rapid? Just after the disappearance of 

 the vacuole look closely for radiating canals in the same 

 region. If more than one vacuole is present observe whether 

 they contract and expand together. What is the nature 

 of the contents of the contractile vacuoles? What function 

 might they serve? 



The nucleus can rarely be seen in the living animal. In 

 order to render it. visible place a drop of methyl green near 

 the cover glass and draw it underneath by the -use of filter 

 paper. When the excess of stain is replaced by clean water, 

 the nucleus should be visible as a green spot. In what part 

 of the body is the nucleus? This nucleus is called the 

 macronucleus and is rather large; by its side is a smaller 

 nucleus, the micronucleus, which is difficult to demonstrate 

 except by special means of preparation. 



A drawing about four inches long should be made and in 

 it should be represented all the details of structure mentioned 

 above. Also make a drawing of an ideal cross section of 

 the animal through the middle region of the body. 



II. Physiology. 



1. Movements. In what directions may the animal move? 

 What are the means of locomotion? Run some powdered 

 carmine under the cover glass and observe the currents 



