ACTION OF STRYCHNIN K 



219 



What effect lias this on the convulsions? Can you locate 

 the seat of action of the drug from this experiment? In 

 what other ways might you test out your conclusions ''. 



Fig. 209. Tracing showing th'e action of strychnine on the frog made liy the contrac- 

 tions of the gastrocnemius muscle as arranged in Fig. 208. 



This is the usual method for obtaining graphic records to 

 illustrate the action of convulsant poisons. This action can 

 usually be shown quite well on frogs, and since frogs are 

 cheaper and more easily managed than mammals, they are 

 generally used for this purpose. The cerebrum is destroyed. 



