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EXPERIMENTAL PHYSIOLOGY 



pressure soon rises again and returns to its initial value. In the case 

 of the kidney trace there is the same delay before any effect is 

 produced, and then a little later, after the blood pressure begins to 



Fig. 157. — Kidney Volume and Blood Pressure in a Dog. 



alter, the kidney volume falls and remains less for some time, finally 

 expanding, often to a much higher volume than before the injection. 

 Finally, after a variable time it once more returns to its initial state. 

 The explanation of these changes in volume of the kidney may be 



