250 THE ADRENAL SYSTEM AND VASOMOTOR FUNCTIONS. 



sible absence of vasoconstrictors and indirectly confirming the 

 presence of vasodilators. 



The question, therefore, becomes an open one, and, if it is 

 considered from the standpoint of our conception of the process 

 of muscular contraction, i.e., with the vasodilators as the in- 

 citing factor of the oxidation process that underlies muscular 

 activity, the contradictory phenomenon referred to i.e., dila- 

 tion under electrical stimulation may be accounted for, pro- 

 vided, however, vasoconstrictor nerves are eliminated from the 

 function involved. 



Foster states that "this vasodilator action is almost sure 

 to be manifested when the nerve is divided and the peripheral 

 stump stimulated some days after division, by which time com- 

 mencing degeneration has begun to interfere with the irri- 

 tability of the nerve. For example, if the sciatic be divided, 

 and some days afterward, by which time the flushing and in- 

 creased temperature of the foot following upon the section 

 has wholly or largely passed away, the peripheral stump be 

 stimulated with an interrupted current, a renewed flushing 

 and rise of temperature is the result." As we interpret this 

 result, the stimulation means vasodilation. But we have stated 

 that the sciatic, owing to its greater size, would practically 

 alone transmit the energy, leaving the vasodilator uninfluenced, 

 and, if we transfer to the sciatic the constrictor function, the 

 effect should be the opposite of that observed. That a better 

 conductor than the vasodilator is present is shown by the sen- 

 tence "the constrictor fibers also appear to be more readily 

 affected by a tetanizing current than the dilator fibers." The 

 sciatic itself being looked upon by us as the vasoconstrictor, 

 we can, therefore, connect the remark with this nerve. Bear- 

 ing this fact in mind, we will now inquire into the comparative 

 behavior of the sciatic as a motor-constrictor nerve with its 

 antagonist, the vasodilator, under the conditions mentioned: 

 i.e., section, followed some days later by stimulation, utilizing 

 quotations from Professor Fosters text as the basis of our 

 analysis. 



Eef erring to the sciatic and brachial plexus, he says: "The 

 constrictor fibers appear to predominate in these nerves, and 

 hence constriction is the more common result of stimulation." 



