THE FROG. 87 



STUDY OF THE LIVE FROG. 



1. Put a live frog into a tub of water and study carefully 

 its mode of swimming and floating. 



2. Notice how the frog sits when at rest. 



3. What has the frog in common with other animals that 

 jump well ? 



4. Watch closely the frog's breathing, paying especial 

 attention to the throat, nostrils, and sides. 



5. Touch the eyeball with a pencil, and note what fol- 

 lows. 



6. Note the motions of the eyelids. 



7. What does the frog eat, and how does it take its 

 food? 



8. Look for slight pulsations near the end of the back- 

 bone on each side, near the anus. These are the 

 beatings of the lymph-hearts. 



Make drawings of the live frog in the sitting pos- 

 ture. 



EXTERNAL FEATURES OF THE FROG. 



Kill a frog by wrapping it in a towel or piece of cloth of 

 any kind, and moistening the latter with chloroform ; or 

 put a teaspoonful of ether in a fruit -jar nearly full of 

 water, immerse the frog in it, and cap the jar. 



1. Has the frog a neck? Find the division between the 

 head and the body by bending the parts and feeling 

 for the joint. 



2. Back of and below each eye is an oval area, the mem- 

 brane of the ear-drum, or tympanum. 



