common to both, and tke upper eye-lid one 
proper to itself. 
1. The orbicularis palpebrarum arises from 
the outer edge of the orbitar process of the 
superior maxillary bone, and from a tendon 
near the inner angle of the eye then sur- 
rounding the aye, and covering the eye-lids, it 
is inserted into the nasal process of the superior 
maxillary bone. Its use is to shut the eye. 
2. The levator palpebrae superioris arises 
[from the upper part of the foramen opticum, 
I and is inserted into the tarsus of the upper 
•eye-lid. Its use is to open the eye. 
Muscles of the eye-ball. 
The muscles which move the globe of the 
-eye are six, viz. four straight and two oblique. 
The four straight muscles very much re- 
'Semble each other, and arise from the bottom 
[ of the orbit around the foramen opticum of 
the sphenoid bone. They are inserted at the 
fore part of the globe of the eye into the an- 
terior part of the tunica sclerotica, and under 
tiie tunica adnata, at opposite sides, which 
indicates both their names and use ; so that 
they scarcely require any further description, 
but to name them singly. They are the le- 
vator oculi, depressor oculi, adductor oculi, 
jasul abductor Oculi. 
The oblique muscles are two: 
1. The obliquus superior, or trochlearis, 
" .arises from the edge of the foramen opticum 
at the bottom of the orbit, between the leva- 
j tor and adductor; hence it runs through a 
I cartilaginous trochlea on the inside of the in- 
| ternal angular process of the os frontis, and is 
inserted into the tunica sclerotica, between 
the attollens and optic nerve. Its use is to 
roll the globe of the eye, and to turn the pu- 
pil downwards and outwards. 
2. The obliquus inferior arises from the 
outer edge of the orbitar process of the supe- 
| -rior maxillary bone, and is inserted into the 
[ sclerotica, between the abductor and optic 
nerve. Its use is to oppose the superior. 
Of the muscle of the nose. 
There is only one muscle on each side that 
<can be called proper to the nose, though it is 
affected by several muscles of the face. 
The compressor naris arises from the root 
of the ala nasi externally, and is inserted slight- 
•iy into the anterior extremity of the os nasi. 
Its use is to compress the ala towards the sep- 
tum nasi. 
Muscles of the mouth and lips. 
The mouth has nine pair of muscles, which 
are inserted into the lips, and a common one 
formed by the termination of these, viz. three 
above, three below, three outwards, and the 
common muscle surrounding the mouth. 
The three above are, 
1. The levator anguli oris arises from a hol- 
low of the superior maxillary bone, and is in- 
serted into the angle of the mouth. Its use 
is to draw the corner of the mouth upwards. 
2. The levator labii superioris alzeque nasi 
arrises by two origins ; the first from the exter- 
nal part of the orbitar process of the superior 
maxillary bone ; the second from the nasal 
process of the superior maxillary bone. The 
iirst and shortest portion is inserted into the 
supper lip and orbicularis labiorum ; the se- 
l cond and longest into the upper lip and outer 
part of the ala nasi. Its use is to raise the up- 
AN ATOMY. 
per lip and ala nasi towards the orbit, and a 
lithe outwards. 
3. The depressor labii superioris alarque 
nasi arises anteriorly from the os maxillare su- 
perius, and is inserted into the upper Up and 
root of the ala nasi. Its use is to draw the 
upper lip and ala nasi downwards and back- 
wards. 
The three below are, 
1. The depressor anguli oris arises from the 
lower edge of the maxilla inferior, and is in- 
serted into the angle of the mouth. Its use 
is to pull down the corner of the mouth. 
2. The depressor labii inferioris arises from 
the inferior part of the lower jaw, and is in- 
serted into the edge pf the under lip. its use 
is to pull the under lip and skin of the chin 
downward and outward. 
3. The levator labii inferioris arises anteri- 
orly from the lower jaw, and is inserted into 
the under lip and skin of the chin. Its use is 
, to pull the parts into which it is inserted up- 
ward. 
The three outward are, 
1. The buccinator arises from the lower 
jaw, as far back as the last dens molaris and 
root of the coronoid process ; from the upper 
jaw, between tire last dens molaris and pte- 
rygoid process of the sphenoid bone; and is 
inserted into the angle of the mouth. Its use 
is to draw the angle of the mouth backward, 
and to contract its cavity. 
2. The zygomaticus major arises from the 
os mala:, near the zygomatic suture, and is 
inserted into the angle of the mouth. Its use 
is to draw the corner of the mouth upward 
and outward. 
3. Tire zygomaticus minor arises above the 
origin of tire former, and is inserted near the 
corner of the mouth. Its use is to draw the 
corner of the mouth outward and upward. 
The common muscle is, 
The orbicularis oris. This muscle is, in a 
great measure, formed by the muscles that 
move the lips, and surrounds the mouth like a 
sphincter. Its use is to shut the mouth. 
Muscles of the lower jaw. 
The lower jaw has four pair of muscles for 
its elevation or lateral motions, viz. tv/o which 
are seen on the side of the face, and two con- 
cealed by the angle of the jaw. 
1 . The temporalis arises from a semicircu- 
lar ridge of the parietal bone, and from all 
the temporal fossa of the cranium, and is in- 
serted into the coronoid process of the lower 
jaw. Its use is to puli the lower jaw upwards. 
2. The masseter arises from the inferior 
and interior part of the zygoma, and is inserted 
into the outside of the angle of the lower jaw. 
Its use is to pull the lower to the upper jaw. 
3. The pterygoideus internus arises from 
the pterygoid fossa, and is inserted into the 
angle of the lower jaw internally. Its use is 
to draw the jaw upwards and toward the op- 
posite side. 
4. The pterygoideus externus arises chiefly 
from the outer side of the external pterygoid 
process, and is inserted into the fore part of 
the condyloid process. Its use is to pull the 
lower jaw forwards, and to the opposite side. 
The muscles which appear about the anterior 
part of tke neck. 
On the side of the neck are two muscles or 
layers: 
79 
1. The niusculus c.utaneus vulgo plntysma 
myoides arises from the cellular substance that 
covers the upper parts ot the deltoid and pec- 
toral muscles, and is inserted into the inte- 
guments covering the side of the lower jaw. 
Its use is to corrugate the integuments to 
which it is attached. 
2. The sterno-cleido mastoideus arises by 
two distinct origins ; the anterior from the top 
of the sternum ; the posterior from the upper 
and anterior part of the clavicle ; both unite 
to be inserted into the mastoid process. Its 
use is to turn the head to one side, and bend 
it forward. 
Muscles situated between the lower jaw and 
os hyoides. 
There are four layers before, and two mus* 
cles at the side. The four layers are, 
1. The digastricus arises from the fossa at 
the root of the mastoid process of the temporal 
bone, becomes tendinous, runs through the 
stylo-hyoides, is fixed by a ligament to the os 
hyoides, and then runs forwards and is insert- 
ed into a roughness at the inferior edge of the 
chin. Its use is to open the mouth, or to 
elevate the larynx, &c. 
2. The mylo-hyoideus arises from all the 
inside of the lower jaw, and is inserted into 
the basis of the os hyoides. Its use is to pull 
the os hyoides forwards, upwards, and late- 
rally. 
3. The genio-hyoideus arises from the 
middle of the lower jaw internally, and is in- 
serted into the basis of the os hyoides. Its 
use is to draw this bone forward to the chin. 
4. The genio-hyo-glossus arises from the 
inside of the middle of the lower jaw, and is 
inserted into all the length of the tongue, and 
base of the os hyoides. Its use is, according 
to the direction of its fibres, to depress the 
tongue, or to draw the os hyoides forward. 
The two muscles at the side are, 
1. The hyo-glossus arises from the base, 
cornu, and appendix of the os hyoides, and 
is inserted into the side of the tongue. Its 
use is to- pull the tongue inward and down- 
ward. 
2. The lingualis arises from the root of the 
tongue laterally, and is inserted into the tip 
of the tongue. Its use is to contract the sub- 
stance of the tongue. 
Muscles situated between the os hyoides and, 
trunk. 
These may be divided into two layers. The 
first layer consists of two muscles: 
1. The sterno-hyodeus arises, thin and 
fleshy, from about the cartilaginous extre- 
mity of the first rib, and is inserted- into the 
base of the os hyoides. Its use is to- pull the 
os hyoides downwards. 
2. The omo-hyoideus arises from the su- 
perior costa of the scapula, near the semilu- 
nar nitch, and is inserted into the base of the 
os hyoides. Its use is to pull the os hyoides 
obliquely downwards. 
The second layer consists of three muscles : 
1. The sterno-thyroideus arises from the 
inner edge of the uppermost bone of the 
sternum, and is inserted into the rough line 
at the inferior edge of the thyroid cartilage. 
Its use is to draw the larynx downward. 
2. Thyreo-hyokleus arises from the rough 
line opposite to the former, and is inserted 
into part of the basis, and almost all the cornu 
