EAETHWOEM 135 



PHYSIOLOGY 



While studying the live worm be careful to moisten 

 its body from time to time with water. 



a. Movements. — Lay a live earthworm on a smooth sur- 

 face, as on a planed board or a piece of glass. 

 ISTote the manner in which the worm moves. 

 What are its various motions ? Can it move for- 

 ward ? Backward ? From side to side ? 



Lay the worm on a rough surface, e. g., an un- 

 planed board or a piece of fine sand-paper. Com- 

 pare the movements with those made on a smooth 

 surface. Is progression any easier than before ? 

 Explain. Incline the board at an angle. Can 

 the worm climb up the board? If so, at how 

 steep an incline ? Hold the worm somewhat 

 closely in the hand and study carefully the man- 

 ner in which the animal makes its escape. In 

 what way do the setae aid it in its efforts ? Put 

 a worm in water. Can it swim ? Does it en- 

 deavor to get out of the water? Why do we 

 find so many worms on the ground after a rain ? 

 Place the worm on the surface of the closely, but 

 not tightly, packed earth in a flower-pot. Does 

 the animal move any more readily than on the 

 rough board ? Explain. Note its attempts to 

 burrow into the earth. What part of the body 

 does it use most ? In what manner is this part 

 employed ? Is this part especially adapted to 

 the purpose in its shape, structure, etc. ? How 

 is the rest of the body employed during the act 

 of burrowing ? How long does it take to make 

 the burrow large enough to contain the entire 



