14 NATURE-STUDY LESSONS. 



VII.-THE HAND. 



A. General Appearance. 



1. Examine your hand closely. 



2. How is it connected with the arm? 



3. Move the hand in as many directions as you can 

 while keeping the arm at rest. 



4. In how many directions can you move your hand ? 



5. Infer the purpose of the wrist. 



6. By feeling carefully the wrist of one hand between 

 the thumb and fingers of the other, meanwhile moving 

 the former hand in different directions, discover how the 

 structure of the wrist is adapted to the various move- 

 ments of the hand. 



7. Describe the part of the hand joined to the wrist. 



8. Compare the back and front of this part as to form. 



9. Account for this difference in form by reference to 

 their respective uses. 



B. Its Skin. 



10. {a) Compare the appearance of the skin in the front 



(palm) of this part with that on the back 

 of it. 

 (3) Compare the movability of the latter with that 

 of the former. 



(c) Which is the thicker ? 



(d) Discover the purpose in this difference. 



(e) What effect has work on the palm of the hand? 

 if) What causes blisters ? 



{g) Observe the wrinkles in the skin on the back 

 of the joints and account for them. 



11. Describe the markings on the palm. 



12. Observe the palm as you close the hand and dis- 

 cover the cause of these lines and of their directions. 



