NEUROLOGY. 127 
cast of the head of Napoleon; /ig. 4, that of Tiedge; fig. 5, of Kant; jig. 6, 
of Talleyrand ; fig. 7 represents the skull of Schiller; fig. 8, that of a Green- 
lander; jig. 9, that of a suicide; fig. 10, that of a poisoner; fig. 11, that of 
a Cretin; jig. 12, that of an idiot; fig. 13, that of a brown sajou ape; jig. 
14, that of a Grison ape. 
4, ANATOMY OF THE NERVES. 
A. Cerebral Nerves. 
1. OtFactory Nerves. First Parr. This pair of nerves is the first 
given off, arising from the inferior anterior surface of the brain. From the 
bulb which each of these nerves forms at the side of the crista galli, several 
branches descend into the nose through the foramina in the cribriform plate ; 
they may be divided into the internal, middle, and external. The znternal 
branches, about ten in number, descend in grooves along the septum, and 
subdivide into many filaments, which form a plexus with each other in the 
mucous membrane. The iniddle branches are distributed to the mucous 
‘membrane lining the roof of each nostril. The external branches descend 
along the groove, on the turbinated bones, dividing and communicating 
frequently with each other, so as to form numerous plexuses which are lost 
in the pituitary membrane. 
2. Optic NERVES. SeconpD Parr. ‘This arises by a broad flattened root, 
one portion of which comes from the thalamus opticus, and another from 
the testis; a@vancing it adheres so closely to its fellow, that the two seem 
fused together, in such a way that there is no line of separation between 
them. This junction presents the form of the letter X, and is called the 
chiasma. Separating again after this union, each nerve passes through its 
optic foramen, and piercing the sclerotic and choroid membranes of the eye, 
expands to form the retina. This nerve is accompanied by the ophthalmic 
artery. The other nerves distributed to the eye are, the third nerve, the 
fourth, the ophthalmic branch of the fifth, and the sixth. | : 
3. THE Morores Ocul. THtrp Pair. This arises from the internal face 
of the crus cerebri, in advance of the anterior margin of the tuber annulare. 
After passing through the foramen lacerum orbitale, it divides into two 
branches, a superior and an inferior. ‘The superior or smaller passing above 
the optic and nasal nerves, divides into two branches, one to the superior 
rectus, the other to the levator palpebre. The mferior or the larger branch 
passes below and to the outside of the optic nerve, and divides into three 
branches: an internal, to the internal rectus ; a middle, to the inferior rectus ; 
and an external, to the inferior oblique. 
4, THE TROCHLEATOR PaTHETIcus. FourrH Pair. This is the smallest 
“nerve coming from the encephalon, not exceeding a sewing thread in thick- 
ness. It arises by two roots from the upper anterior face of the valve of 
‘the brain, just below the testes; passing through the foramen lacerum 
orbitale, it reaches the eye, and is distributed to the superior oblique 
muscle. 
ICONOGRAPHIC ENCYCLOPADIA.—VOL, II. 53 833 
