260 EXPERIMENTAL PHAEMACOLOGY 



strychnine. After death dissect out the ducts and chorda 

 tympani nerve on the opposite side. Can you easily dif- 

 ferentiate between the two ducts? Can you locate the 

 chordo-lingual triangle? Cut out (label} both eyes and 

 place them in thirty per cent alcohol. Save for dissection 

 later. 



EXPEEIMENT LVI. 



Coniine. (Frog 1 : Heart and Vagus Nerve.) 



1. Pith a frog, arrange for taking a heart tracing and 

 stimulate both the vagus trunk and the crescent. Get rec- 

 ords showing the inhibition from each of these. Drop two 

 or three drops of a one per cent coniine solution on the 

 heart. How does this affect the record? Now stimulate the 

 vagus and crescent again and record the results. What do 

 you observe ? How do you explain this 1 What other struc- 

 tures are similarly affected by coniine ? Make a diagram of 

 the innervation of the heart (Fig. 222) of the frog in your 

 permanent note book and indicate on it the structures af- 

 fected by coniine and state the nature of this action. Apply 

 sufficient coniine to the heart to bring it to a standstill. Do 

 you know of any other drugs that act like coniine 1 Watch 

 for these later. 



EXPEEIMENT LVII. 



Coniine. (Turtle: Heart and Vagus Nerve, Lungs and 



Sympathetic Nerves.) 



1. Repeat Experiment LVI on a turtle and secure rec- 

 ords to show the action of the drug. After a record show- 

 ing the specific action of the drug on the ganglia has been 

 obtained (how would you prove this?) then unhook the 

 heart lever and remove the turtle from the drum. (It is 

 often advisable to use a fresh turtle for this part of the ex- 

 periment. Large turtles are preferred.) Consult Fig. 232 



