126 INTRODUCTION TO ZOOLOGY. 



4. See the ligaments which hold the bones 

 together. 



5. See the cartilage which covers the ends of the 

 bones. 



6. Feel the slippery surface of the end of one of 

 the large bones. Synovia, or joint water, renders it 

 slippery. 



7. Find a lining over the bones, completely cover- 

 ing them. This is the jperiosteum. 



8. Study the muscles on the hind leg. Separate 

 one muscle from all the others. Study it. 



9. Notice the muscle sheath, a very thin, trans- 

 parent membrane over all the muscle. 



10. Note the tendon, a tough white cord at the 

 end of the muscle. Find the place in which the ten- 

 don is attached to the bone. The place of attachment 

 Avhich is nearest the central part of the body is called 

 the origin. The attachment at the other end is called 

 the insertion. 



11. Separate a small part of muscle into stringy 

 pieces as small as you can. The finest pieces into 

 which you can separate it are called muscle fibers. 



12. A muscle fiber, when highly magnified, shows 

 short markings across it. These markings are called 

 striations, or striae. Voluntary muscles, or those 

 under control of the will, are all composed of striated 

 fibers. So is the heart, which is an involuntary mus- 

 cle. It is probable that striations are more closely 

 associated with the frequency and vigor of contraction 

 than with its voluntary or involuntary character. 



Review Questions oii the Rabbit. 



1. What is the covering of a rabbit? 



2. What is its color? Is this color an advantage? 



3. Tell of the length and color of the tail. Is this 



color of any use? 



