264 THE ADRENAL SYSTEM AND VASOMOTOR FUNCTIONS. 



of Contejean, "according to which the secretion of gastric 

 juice continues after the stomach has been deprived of all its 

 nerve-connections/' The reason for this is now clear. Inas- 

 much as the motor nerves merely excite to action and regulate 

 this action through their impulses, severance of the nerve- 

 supply of an organ only annihilates this function, and, as the 

 agency that supplies it with working energy reaches its tissues 

 through the blood, it is plain that its functional activity should 

 continue, even when its motor nerves are severed. 



As regards the tonic contraction of vessels ascribed to the 

 sympathetic vascular fibers, it is merely the result of the con- 

 tinuous, though passive, activity in which all muscular tissues 

 are held by the oxidation process, which continues as long as 

 blood flows in physiological channels. This includes the in- 

 creasing, though perhaps slower, filtration of oxidizing plasma 

 into the contractile elements of the muscular fibers of the 

 vascular walls, and its return to the blood-stream per se 

 charged with products of combustion. As previously stated, 

 these do not only represent the products of hydrocarbon com- 

 bustion, the specific source of muscular energy, but also those 

 resulting from metabolism of the cellular elements per se. In 

 other words, a relatively small amount of oxidizing plasma 

 is incessantly penetrating to the myosinogen and causing the 

 development of just sufficient energy to insure nutrition of the 

 tissues and to keep them in that potential state in which, 

 though not doing active work, they are ever ready to actively 

 respond to summonses: i.e., to "motor-nerve" impulses. A 

 skeletal muscle, held by its two insertions, is not free to con- 

 tract in obedience to what energy the continuous oxidation 

 process generates, and, not being at once converted into work, 

 this energy is dissipated as heat. But not so with the vas- 

 cular walls; having only the centrifugal resiliency of their 

 inner coat to contend with, they at once convert the chemical 

 energy generated by the reaction in their contractile elements 

 into work which manifests itself as "tonic" contraction. 



We have stated that voluntary muscles possessed no vaso- 

 constrictor or vasodilator nerves per se, and that the functions 

 ascribed to such nerves were exercised through the agency of 

 the "motor" nerves. What is now termed a vasoconstrictor 



