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EXPERIMENTAL PHYSIOLOGY 



Here we find the exact converse to the results with normal respiration, 

 t.e. a fall in pressure during inspiration and a rise during expiration. 

 In inspiration the thorax is now expanded by pressure from within ; 

 and, as the pressure is greater from within than without, the flow into 

 the auricle is impeded. The result is well seen in fig. 136, which is 



Fig. 137. — Stimulation of the Depressor Nerve in a Babbit. 

 Time Tracing Seconds. 



from a curarised cat anaesthetised with morphia. Artificial respiration 

 was for a time stopped with the thorax in an expiratory state. The 

 pressure showed a gradual constant rise. Then when a fresh inflation 

 was caused the pressure rose for two heart beats and then rapidly 

 fell to rise again during expiration. The initial rise was due to 



