BRONCHIOLE TRACINGS 



379 



heart respond. AVhat conclusions can you draw from this .' 

 Replace the ergamine into the burette (if it was emptied out 

 before) and take a normal record. Inject a dose of er- 

 gamine (gauge the size by your previous experience the 

 dose should be a little larger than that which was previously 

 just sufficient to produce a maximum effect, for the animal 

 becomes a little less sensitive all the time to the drugs). 



Fig. 315. Tracing showing the action of arecoline, ergotoxine. (arecoline) and adrenaline 

 on the bronchioles and blood-pressure in a pithed dog. 



