194 



EXPERIMENTAL PHYSIOLOGY 



Typical tracings obtained in such a demonstration are given in 

 the following figures. It is seen that as a rule the trace follows 



Fig. 156. —Simultaneous Tracing of the Volume Changes of the Kidney and 

 of the Carotid Blood Pressure in a Dog. Time Tracing Seconds. The 

 Horizontal Line marks Zero Blood Pressure. 



exactly the curve of blood pressure simultaneously recorded. The 

 variations in volume with each heart beat are well marked, and the 



