5. After watching the animal for some time, describe the path followed by a given specimen as it crosses the field of the microscope. What reason can you see, if any, why this paramecium is moving? What external factors, if any, seem to determine the path it follows? 6. How rapidly do paramecia really move? What structures do they use in locomotion? How do they manage to move in one direction, instead of alternately backward and forward? How do they manage to move in a straight line, though their bodies are not symmetrical? 7. What is the food of the paramecia? How do they find it? Find a specimen at rest and watch the oral groove. Suggest a method by which food may be collected into it. If possible, note the process of swallowing, and the resulting food ball. _Note._--If powdered carmine be placed in the water with some paramecia, it can be seen in the food balls a half hour or so later. 8. Where are the food balls located? Watch them in an individual until you notice their motion. Where are the larger food balls? the smaller ones? Assuming them to have been of approximately equal sizes when they were taken in, how can you account for differences now? 9. Where are the contracting vacuoles? How many are there? How often does one contract? What is their function? 10. As you have been studying paramecia, to what external influences (as contact, heat, light, etc.) have you seen them respond? How do they show it when they do respond? Is such a response an advantage to them or not? What would be the result if they were not able to detect changes in their surroundings? 11. Where does respiration occur in paramecia? Where do they obtain their supply of oxygen? 12. Among the paramecia you are studying you usually find at least one in the process of fission. Watch it until the halves separate, if you can. Compare the halves. Do they rank as parent and offspring? If so, which is which? If not, which are they, parent or offspring? 13. If you happen to find a pair conjugating, notice the process, as far as you can, in the living animals. _Suggested drawings._ a. A drawing to show all the details seen in the living paramecium. b. A diagram to show the path followed by a paramecium to get around some obstacle. c. Drawings to show that paramecia are constant in shape and yet flexible. d. A drawing to show at least one stage in fission. This may be from a permanent preparation. e. A drawing to show paramecia conjugating. This also may be from a permanent preparation. f. Instead of all these separate drawings they may be combined into one. Represent the field of the microscope, and in it draw all necessary figures, to show the facts called for in the first five drawings and any other facts you have observed about living protozoa. Make the whole drawing to scale. Summary of Important Points in the Study of Paramecia