68 LABORATORY EXERCISES. 



it apart with the needles until you have the 

 smallest portion of the bundle which you can 

 get. Place this bit of muscle on a glass slide, 

 add a drop of water, and tease it out with 

 needles; cover with glass and examine under 

 the high power of the compound microscope. 



1 . Of what is the piece of muscle found to con- 



sist? 



2. Why is this kind of muscle called striped 



muscle? 



3. Draw a muscle-bundle as seen under the 



microscope. Label fibres, cross-stripes. 



35. STRUCTURE OF A JOINT. 



Materials: Fresh leg-joint of lamb or veal; scalpel. 



A. Movement at the joint. 



1. Hold one of the bones in a fixed position; 



in how many directions can the other 

 bone be moved? 



2. What prevents the joint from moving in 



other directions? 



B. Muscles and tendons. 



1. Dissect away the muscle with the scalpel; 



by what are the muscles attached to the 

 bones? 



2. Try to stretch or break these cords (ten- 



dons) ; what properties of tendons does 

 this demonstrate? 



3. What is the advantage of the absence of 



muscle-tissue over joints? 



