MYOLOGY. 55 
third cervical vertebra. Use: to bend the neck on one side, and rotate the 
atlas on the vertebra dentata; when both muscles act, they bend the neck 
directly forwards. 
Rectus capitis anticus major, long and flat, thick above and below, arises 
by small tendons from the anterior tubercles of the transverse processes of 
the last four cervical vertebrze; they soon unite in a fleshy substance, which 
is inserted into the cuneiform process of the occipital bone. It serves to 
bend forwards the head and neck. 
Rectus capitis anticus minor, short and narrow, arises from the transverse 
process of the atlas, and is inserted into the cuneiform process. It serves 
to bend the head forwards and to one side on the atlas. 
Rectus capitis lateralis, very short, arises from the transverse process of 
the atlas, and is inserted into the semilunar ridge or jugular process of the 
occipital bone which extends from the condyle to the mastoid process. 
With the last muscle it serves to bend the head forwards or to incline it to 
one side. 
Scalenus anticus, in part continuous with the rectus anticus major, arises 
from the anterior tubercles of the transverse processes of the third, fourth, 
fifth, and sixth cervical vertebrae; the fibres descending form a flat muscle, 
which is inserted tendinous into the upper surface of the first rib, near its 
cartilage. Its use is to bend the neck forwards and laterally, also to elevate 
and fix the rib, as in inspiration. 
Scalenus medius, larger and longer than the last, arises from the posterior 
tubercles of the transverse processes of four or five inferior cervical verte- 
bree, and is inserted into the upper surface of the first rib, behind the sub- 
clavian artery. Its use is similar to that of the last. 
Scalenus posticus arises from the posterior tubercles of two or three lower 
cervical vertebree, and is inserted into the upper edge of the second rib, 
between the tubercle and angle. Use: to elevate the second rib; to bend 
the neck to one side and a little backwards. 
Pl. 127, fig. 3", platysma myoides; *, branch of the latter known as 
musculus risorius santorini; *, sterno-cleido-mastoid ; *, trapezius. 
Fig. 4°, the digastric muscle. 
Pl. 124, fig. 15", platysma myoides. 
Pl. 125, fig. 19’, sterno-cleido-mastoid. 
C. Muscles of the Anterior and Lateral Parts of the Thorax. 
The thorax is the middle division of the body, continuous with the neck 
above and the abdomen below; it presents an anterior or sternal, a posterior 
or dorsal, and two lateral aspects. 
Pectoralis major, flat and triangular, arises from the sternal half of the 
clavicle, from the anterior surface of the sternum, from the cartilages of 
the third, fourth, fifth, and sixth true ribs, and from an aponeurosis common 
to it and to the external oblique muscle; its fibres are inserted by a flat 
tendon into the anterior edge of the bicipital groove, and by an aponeurosis' 
into the fascia of the arm. A line of cellular membrane separates the 
clavicular from the sternal portion, these in some cases appearing as dis- 
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