XIV.] BLOOD PRESSURE. 153 



that c of Y, and the pump working exactly 



as before, measure again the outflow during 



ten seconds. 



The outflow of Y will be increased. That of 



X on the other hand will be diminished, 



though the resistance in X is the same as 



before. 



The flow of blood through an artery is dependent 

 not only on the resistance offered by its own 

 small arteries and capillaries but also on that of 

 other arteries. 



DEMONSTRATIONS. 



1. The effects in the rabbit on the temperature of 

 the ear, and on the calibre of its blood-vessels, 

 following 



a. Stimulation of the central end of the great 

 auricular nerve. 



b. Section of the sympathetic nerve in the neck. 



c. Stimulation of the peripheral end of the 

 sympathetic. 



2. Normal kymographic tracings of the blood-pres- 

 sure of a mammal obtained by the use of a 

 mercurial manometer. 



3. The effects on the arterial blood-pressure, as 

 indicated by the tracing, produced by 



a. Inhibition of the heart through stimulation 

 of the peripheral end of the vagus. 



