VERTEBRATES 147 



4. What uses have the fore or the hind limbs other than 

 locomotion ? Explain how the usual sitting or resting 

 posture is advantageous for quick locomotion. 



5. By means of printer's or writing ink smeared over 

 the soles of the feet, and a long piece of clean white paper 

 get prints of a rabbit's tracks as it hops over the paper. 

 Explain how the peculiar formation of the tracks occurs. 



Feeding. 6. Offer a rabbit various kinds of food. How 

 does it test the food before eating .' Does the rabbit ever 

 use its forelimbs to assist in feeding ? If so, when and 

 how > How is the food eaten ? How are the teeth fitted 

 for the rabbit's method of feeding ? Does your rabbit 

 drink .'' If so, how ? 



Respiration. 7. What movements of the body are 

 concerned in breathing } 8. Compare the frequency of 

 the breathing movements with your own. Can you distin- 

 guish the heart beats .' If so, how and where t Count 

 them. 



Sense Organs. 9. Note the position of the eyes, shape 

 of their surface, shape and size of the pupil. What ex- 

 ternal protecting structures are present, — such as eyelids, 

 eyelashes, eyebrows.? Study the movements of the eye- 

 lids. Is there a third eyelid as in the bird } Compare the 

 use of the neck in enlarging the range of vision with that 

 of the bird. Is the rabbit's range of vision greater or less 

 than your own .-' 



10. What is the location of the nostrils ? What advan- 

 tages are gained by the prolongation of the face forward } 

 Note any peculiarity in the form or movement of the nos- 

 trils. How do you explain these movements .' Are the 

 nostrils more or less useful than those of other vertebrates 

 you have studied .' How ? 



11. Note the shape, size, and position of the external 



