Annulata. 



49 



4. Try the effect of sound on earthworms, being careful that 

 they do not get vibrations that affect the sense of touch during 

 the experiments. 



5. Try the effects of light, being careful not to apply heat at 

 the same time. Place the worm in a glass tube, and let the light 

 fall upon one part at a time, covering the rest of the tube with a 

 cylinder of black paper. Try also the effect of heat without 

 light. 



6. Repeat any experiments given under " Field Study " that 

 may profitably be reviewed. 



7. What is the appearance of the surface of the soil as a result 

 of the work of earthworms ? What effect do earthworms produce 

 in the condition of the soil ? 



STUDY OF A LIVE EARTHWORM. 



1. Place a live, active earthworm on a large sheet of paper and 

 watch its behavior. Does it move with the same end always fore- 

 most ? Touch the end that is foremost to see if it will reverse its 

 motion. What changes take place in its body during locomotion? 

 Can you explain how it progresses ? 



2. Take the earthworm in the fingers of one hand and draw it 

 over a finger of the other hand to feel the bristles ; of what use 

 are they? Can you learn how they are arranged? Do they point 

 more toward one end of the body than the other? Place the 

 worm on glass ; can it crawl as well as on paper ? Why should 

 the condition of the surface affect the worm's locomotion? 



3. Touch various parts of the body to learn the degree of 

 sensitiveness of different parts. 



4. Turn the worm over on its back ; does it remain in this 

 position ? 



5. Take hold of the posterior end of the worm and drag it 

 backward along the paper ; listen for any sound thus produced. 

 How explain this result? 



6. Rap sharply on the table ; does this affect the worm ? 



7. Place the worm on a wet surface, and after a while on a dry 



