13 



column connected with the iliac bones. Skin the hind legs, 

 but just before doing so cut through the ligature ; then 

 dissect out the sciatic nerve, p 19, (2), (3) and (4) (figs. 6 

 and 7). 



Sc.ia.iic A/erve 



Biceps 

 FIG. 7. Dissection of Sciatic Nerve. 



Apply the electrodes to the structures indicated below, and 

 stimulate by closing and opening the mercury key. 



RESULT. 



Normal frog, (a) Sciatic nerve. 



(6) Gastrocnemius muscle. 



Curarised frog, 1. Limb exposed to curare (unligatured). 

 (a) Sciatic nerve. 

 (6) Gastrocnemius muscle. 



2. Limb protected (ligatured). 



(a) Sciatic nerve (above where ligature 



was applied). 

 (6) Gastrocnemius muscle. 



Record the results on the appended table : 



CONCLUSIONS. 



1. What is the influence of nerve upon skeletal muscle ? 



2. What is the influence of curare upon (a) nerve, (6) 



muscle, and (c) the junction of nerve with muscle ? 



