44 NATURE-STUDY LESSONS. 



F. Its Ears. 



10. (a) Discover whether it can hear. 

 (3) Has its ears external openings? 



G. Its Skin. 



11. («) Describe the covering of the snake 

 (6) Count the rows of scales. 



(c) Note whether the scales are flat or ridged. 



(d) Beginning at the middle row on the back give 



each row a number — one, two, three, etc., 

 and tell its color. 



12. Compare the scales on the under side of the body 

 with those on the upper side in respect to size, shape 

 and color, and infer why there should be such difference. 



13. Compare the scales on the head with those on the 

 back. 



14. Make a drawing of the head. 



H. Its Movements. 



15. Use a pane of glass for the floor of the box, and 

 observe how the snake moves itself. 



I. Its Casting its Skin. 



16. («) Give it food and water and keep it in confine- 



ment until it sheds its skin. Its sluggishness 

 and dull eye will warn observers of the time. 

 (d) Observe how the skin comes off. 



This may occupy several minutes only, but more likely several hours. 



If a descriptive text-book is at hand Fifth-form pupils will be interested 

 in counting the gasterosteges, urosteges and rows of scales and noting the 

 characters of the cephalic plates, in order to identify the species. 



17. Illustrate the record of your observations with 

 drawings wherever you can, 



