46 ELEMENTARY PHYSIOLOGY. VII. 



close to the tendon, there will be no change ; then place 

 a similar drop on the middle of the muscle, there will be 

 local contraction, slow enough to be followed by the 

 eye. The part of the muscle fibres under the nerve end- 

 ings (neural region) is much more responsive to nicotine 

 (and to some other stimuli) than the part near the 

 tendon. 



3. Spontaneous contractions of unstriated 

 muscle. Tie the lower end of the large intestine, and 

 of the small intestine. Cut out the large intestine; tie 

 loops in the threads, and fasten it by the loops in the 

 moist chamber, with no weight on the lever, cover with 

 saline solution. Set the drum for the slowest speed. 

 Take the time at which the drum is started, let it run 

 for half an hour and from this calculate the duration of 

 the single contractions. 



4. Remove the skin from the legs. 



a. Cut out both sartorii, place one in curari -005 p.c. 

 for 15 mins. or more, and the other in saline solution. 



b. Cut off both feet, place one in -01 p.c. curari for 

 15 mins. or more, and the other in saline solution. 



c. Make a sciatic -gustrocnemius preparation. 



5. Action of cocaine on nerve. Cocaine annuls the con- 

 ductivity of nerve fibres; the conductivity is recovered 

 slowly on removing the cocaine in contact with the 

 nerve ; the recovery is naturally more rapid if the circu- 

 lation is going on, but occurs in cut out nerve placed in 

 saline solution. 



Place the nerve-muscle preparation ( 1, c) on blotting- 

 paper moistened with saline solution, find (approximately ) 



