TURTLE LUNG TRACING 



263 



When the entrails are removed then cut out all the skeletal 

 muscles you can including the entire hind limbs and most of 

 the muscles of the fore limbs. This exposes the lungs prac- 

 tically free from skeletal muscles. 



Connect the tracheal cannula with a tambour (very sensi- 

 tive, medium-sized bowl) and bring the writing point on to 

 a slow drum. Observe the way the bull-dog is placed in the 



Fig. 234. Tracing showing the contraction of the left lung of a turtle when the left 



vagus nerve was stimulated electrically. 



figure. In a similar manner clamp off one bronchus and 

 then pick up the main trunks of the vagus and sympathetic 

 nerves on the opposite side well up in the neck. See that 

 the lung is partially inflated and the tambour under a slight 

 tension. Start the drum, and with a fairly strong tetaniz- 

 ing current stimulate the vagus and sympathetic trunks 



