138 ANTHROPOLOGY. 
terror tinal, or interosseal nerve, supplies muscles of the leg, and on the tarsus 
divides into an external and internal branch, the Jatter of which, the con- 
tinued trunk, passes to the first and second toes. 4 
The ae popliteal or posterior tibial nerve, is much larger than the pre- 
ceding, being destined to supply the large itntieles on the back of the leg, 
and the muscles and integuments of the sole of the foot. In the ham it gives 
off various articular branches, and one principal cutaneous branch, the 
external saphenous. Continued down the leg, the posterior tibial nerve, at 
the tendo Achillis, gives off several large branches, as the external and inter- 
nal plantar to the lower surface of the foot. 
Pl. 188, fig. 2, crural nerve, and its distribution: *, crural vein; *, crural 
artery ; °, crural nerve; *, external cutaneous nerve; °, branches embracing 
the vessels; °, saphena; ”’, saphenous nerve; *, cutaneous branch from the 
peroneal nerve to the foot. ig. 3, nerves of the sole of the foot: *, division 
of the posterior tibial nerve into’, the inner, and *, the outer plantar nerve ; 
‘, division of the inner plantar nerve into four digital nerves; °, division of 
the outer into a superficial and a deep branch. 
C. Sympathetic System. 
In addition to the five small ganglions on each side, already noticed in 
the description of the cerebral nerves, viz. the Casserian, the lenticular or 
ophthalmic, the spheno-palatine or Meckel’s, the sub-maxillary, the otic or 
the ganglion of Arnold: also, the several ganglions on the posterior roots 
of the spinal nerves: we find one continued chain of these bodies placed 
along the vertebral column, on either side of the median line, and at regular 
intervals. These ganglions, on each side, are all connected to each other, 
and resemble a knotted cord; these cords receive the name of the sympa- 
thetic nerves. 
The sympathetic nerves, therefore, are two in number: they descend from 
the base of the cranium perpendicularly along the neck, and are placed 
anterior to the vertebre, on the rectus capitis and longus colli muscles, and 
behind the great vessels and nerves. At the upper end of the chest, each 
of these nerves is divided by the subclavian artery into several branches, 
which encircle that vessel, and unite below it in the thorax. Through this 
cavity they descend, at first obliquely, backwards, and outwards, along the 
side of the spine, over the heads of the ribs and their stellate ligaments, and 
are covered by the pleura; they then incline a little forwards, and pass 
behind the true hgamentum arcuatum into the abdomen ; through this region 
they descend obliquely outwards on the fore part of the lumbar vertebre, 
between the psoas muscles and the crura of the diaphragm ; they then sink 
into the pelvis, keeping close to the sacrum, and descend along the anterior 
surface of this bone obliquely inwards; near its inferior extremity, or on 
the first part of the coccyx, they unite and terminate in a small ganglion, 
named coccygeal, or impar. The superior extremity of each sympathetic 
nerve is connected by several filaments with several of the cerebral nerves. 
Some of these connexions, particularly that with the sixth, have been impro- 
perly termed the origin of the sympathetic; at the base of the cranium it 
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