778 THE ADRENAL GLANDS 



mechanisms for the intestine are located in the sympathetic ganglia, those 

 for the limbs are contained in the sympathetic as well as the posterior 

 root ganglia. These mechanisms are of comparatively late development; 

 in newborn mammals (with the exception of rodents) administration of 

 epinephrine in all dilutions produces universal vasoconstriction, and it is 

 not until the animal is several weeks old that dilator effects can be ob- 

 tained, peripheral dilatation is the first to appear, somewhat later dila- 

 tation of the intestinal vessels may be elicited. 



Although it is especially on plain muscular fiber having a sympathetic 

 nerve supply that epinephrine unfolds its action, yet, according to Can- 

 non, Gruber, 18 and others, it increases the contracting power of volun- 

 tary muscle and diminishes the tendency to fatigue. 



