178 



EXPERIMENTAL PHYSIOLOGY 



larger variation with the same force. It is mainly due to the inertia 

 of the recording instrument. With the rapidly beating heart the 

 manometer could only respond to a limited extent to the change of 

 pressure produced ; but now that the beat is slower more 

 time is allowed to the manometer, and its movements therefore 



l\ l\ l\ 



miMMm 



B.P. 



JUJUU'LJlJlJuJlJUlJLJLJLjUUUU 



Fig. 140. 



-Stimulation of the Peripheral End of the Left Vagus 

 in a Rabbit. 



increase in amplitude. After stimulation ceased the rate of beat 

 very quickly increased, and this, aided by an increase in ventricular 

 force and a partial constriction of the arterioles, led to a rise of blood 

 pressure to a greater height than before ; but this was soon followed 

 by a fall, the mean pressure once more attaining its initial value. 

 Fig. 141 is a similar result, but the stimulation was stronger and 



