8 LABORATORY GUIDE IN PHYSIOLOGY. 



sened irritability or destruction of any element in 

 the reflex arc ? 



(//) What effect has the ligature of the thigh on the 

 distribution of the curare ? 



(>) How do the reflex arcs, of which the gastrocnemii 

 are the motor ends, differ with regard to the distri- 

 bution of the curare ? What part of the reflex arc 

 is protected from curare in the ligatured limb? 



(/) Describe the relative reaction of the gastrocnemii 

 to stimuli (chemical, mechanical, electrical) applied 

 to various parts of the body and limbs. 



(#) Is the sensorium intact? Is it reached by the 

 curare? 



(Si) Is the cord intact? Is it reached by curare? 



(3) Expose the sciatic nerves, near the body, in the frog 

 used in experiment (2); stimulate them. 



(a) What elements in the reflex arc enter into consid- 

 eration in this experiment? 



(<) Which of these elements are exposed to, -which 

 protected from the poison ? 



(c) Are both sciatics reached by curare? 



(//) Is there a difference in the reaction of the gas- 

 trocnemii to the stimuli applied to the sciatic 

 nerves? 



O) To what elements of the reflex arc have you lim- 

 ited the possible action of the curare ? 



(/) Have you proven that curare does not affect the 

 nerve trunks? 



(4) Expose gastrocnemii by cutaneous incision. Stim- 

 ulate the muscles directly. 



(a) Is there a difference in reaction to stimuli ? 



() If a muscle in a poisoned animal reacts to direct 

 stimuli, but not to indirect stimuli, though the nerve 

 fibers be proven to be intact, on what element in the 

 reflex arc must the poison act ? 



