30 NATURE-STUDY LESSONS. 



1 8. Examine the teeth of animals to discover the 

 appropriateness of the names incisors, cuspids, bicuspids, 

 molars. 



19. The dental formula shows the number and arrange- 

 ment of the different kinds of teeth that an animal has. 

 That of the adult man is gl^Igls - These numbers show 

 that from the middle of the front the upper jaw has 

 2 incisors, i cuspid, 2 bicuspids and 3 molars, the lower 

 jaw the same. Write the dental formula of the cow and 

 other animals. 



D. The Legs and Feet. 



20. Examine and describe the legs of the cow as to 

 size and length. 



21. (a) Examine the feet. 



(d) Describe their covering. 



(c) How many toes are there on each foot? 



(d) How do these toes differ as to size ? 



(e) How many toes on each foot press the ground 



in walking? 

 (y) Describe the action of the two large toes of 

 each foot in walking. 



22. What is the effect of this when the cow walks in 

 soft soil ? 



A foot covered as that of the cow with such a hard, horny substance 

 is called a Aoof, and when the hoof is cleft or divided is said to be cloven. 



23. Compare the hoof of the cow with that of other 

 hoofed animals, as the horse, the sheep, the goat, the 

 hog, the deer. 



24. Observe a sheep or a goat walking, and note 

 whether the hoof cleaves widely at each step as in 

 the cow. 



