282 THE ADRENAL SYSTEM AND VASOMOTOR FUNCTIONS. 



plan's, Luchsinger's, Onuf and Collins's experimental removal 

 of portions of the sympathetic ganglionic chain attests to 

 this. The latter authors state that "some writers (Nawrocki 

 and Luchsinger, and Langley) go so far as to say that all 

 sweat-fibers destined for the limbs are derived indirectly i.e., 

 through the intermediation of the sympathetic nerve from 

 the spinal cord." That the upper extremities and head are 

 also supplied with them has been emphasized in the foregoing 

 pages. We are warranted, therefore, in ascribing to these fibers 

 the functions of one of our divisions, the "vasoconstrictor," 

 for the entire sudoriferous glandular system. Through these 

 vasoconstrictors the blood-plasma is ultimately brought to the 

 secreting structures, including the spiral muscles, furnishing 

 them with working energy and with the constituents, water 

 included, of the excretion itself. 



If "excito-regulator" nerves exist, to which of the com- 

 ponent parts of the sweat-glands are they distributed? The 

 vasoconstrictor fibers, judging from their role in the voluntary 

 muscular system, may be considered as extrinsic to the sweat- 

 system itself, since they can, by constricting arterioles long 

 before the organ is reached by capillaries, regulate not only 

 the amount of blood allowed within the secreting elements 

 themselves, but also in the spiral muscles around the tubes. 

 We may, therefore, consider the vasoconstrictors as fully ac- 

 counted for topographically, and also as regards the nature of 

 their duties, which coincide with those found to be theirs in 

 the submaxillary gland. The "excito-regulator" nerves, there- 

 fore, must include within their area of influence the remain- 

 ing inherent factors of the local functional process: i.e., con- 

 traction of the spiral muscles and metabolism of the epithelial 

 secreting cells. It is evident that considerable analogy exists 

 between sudoriferous glands and salivary glands. In the sub- 

 maxillary gland we also had, besides the vasoconstrictors, to 

 account for two functions through the one nerve, the chorda 

 tympani, one subdivision of which went to muscular fibers 

 (those of the "blocking" vessels) and the other to the glandular 

 elements. That the excito-regulator division may dichotomize 

 reach of the subdivisions being called upon to excite and 

 regulate a different, though functionally related, structure 

 is evident. 



