CHAP. XXV. A Description of the Intercostal Nerve.
AFter the unfolding of the Nerve reaching forth to the Praecordia and the Ven∣tricle, we are led by the series or order of the inward parts to the describing a Nerve akin to this, and which reaches forth its branches to the furthermost Province, to wit, to all the Viscera or Inwards of the lower Belly contained below the Ventricle. This is commonly called the Intercostal, because that going near the roots of the Ribs, it receives in every one of their Interstices a branch from the spinal Marrow. Its beginning is not yet sufficiently detected; for by most Anatomists it is wrongfully taken for a branch of the wandring pair, though indeed the wandring and the inter∣costal pair do communicate among themselves by branches sent forth one to the other; yet as to both their beginnings, Trunks and wandrings up and down, they are plainly distinguished. If that this latter Conjugation, being denied the title of a peculiar nerve, ought to confess it self of another stock, certainly it owes nothing to the wandring pair, but should borrow its original from the Nerves of the fifth and sixth pairs; for two or three shoots being sent back from those nerves going out to∣wards the Eyes and Face, go into the same stock or Trunk, which is the Trunk of the intercostal nerve, as we have intimated before.
The intercostal Nerve being constituted after that manner, and going out of the Skull at a proper hole, presently contains the Ganglioform infolding, near to ano∣ther the like infolding of the wandring pair; into which two nervous Processes are carried from the last pair within the Skull, or the first Vertebral. From that infold∣ing one shoot is sent forth into the Sphincter of the Throat, and another noted one into the Ganglioform infolding of the wandring pair. Then this nerve descending towards the Vertebrae, hath in the middle of the Neck another far greater infolding, into which an ample nerve, from the neighbouring Vertebral pair, is inserted; but from the same many nerves, which respect the Praecordia, are distributed on every side: For two or three shoots are sent forth into the nerve of the Diaphragma, and one shoot into the returning nerve; besides, numerous fibres and shoots are carried both into the returning nerve, and towards the Trachea, which are inserted into its Coats, and into those of the Oesophagus, and into the blood-carrying Vessels. Fur∣ther, one branch descends into the Trunk of the wandring pair, and two noted nerves into the Cardiack infolding; then a little lower another nerve by it self, proceeding out of the intercostal Trunk, is inserted also into the Cardiack infolding: which noted branches sent down on both sides from the intercostal nerve, for that they joyn