376 THE MUSCLES OF THE DOG 
MUSCLES OF THE NECK 
The cervical cutaneus consists of two strata. One of these is composed of thin 
bundles which curve across the ventral region of the neck and fade out laterally. 
The other layer is thicker and more extensive. Its bundles begin at the dorsal 
margin of the neck, are directed obliquely over the sides, and are for the most part 
continued by the facial part as previously described. 
The sterno-cephalicus is well developed. It arises on the manubrium sterni, 
diverges from its fellow, and ends on the mastoid process, blending with the cleido- 
cervicalis. It may be termed the sterno-mastoideus. It is crossed superficially 
by the external jugular vein. 
The scalenus ventralis (s. prime cost) arises on the last four cervical trans- 
verse processes, and is inserted into the first rib. 
The scalenus dorsalis (s. supracostalis) is large. It blends with the preceding 
muscle in front, and divides into two parts posteriorly. The dorsal part is inserted 
on the third and fourth ribs, the ventral part by a long, thin tendon on the seventh 
or eighth rib. 
The longus colli resembles that of the horse. 
The rectus capitis ventralis major arises on the transverse processes of the 
second to the sixth cervical vertebrae and ends as in the horse. The rectus capitis 
ventralis minor and rectus capitis lateralis resemble those of the horse. 
The intertransversales resemble those of the ox. 
The splenius is strong and extensive. It arises on the first four or five thoracic 
spines and the median raphe of the neck, and is inserted into the nuchal crest and 
mastoid process. 
The complexus is composed of dorsal and ventral parts—the biventer cervicis 
and the complexus major. The biventer cervicis arises from the transverse proc- 
esses of the fifth and sixth, and the spines of ‘the second to the fifth (or sixth) 
thoracic vertebrae, from the ligamentum nuche, and the median raphé. Ithas 
four oblique tendinous intersections. The complexus major arises on the trans- 
verse processes of the first three or four thoracic vertebre and the articular 
processes of the last five cervical. Both end on a strong common tendon which is 
inserted into the nuchal crest and the depression below it. 
The longissimus capitis et atlantis consists of two unequal parts. The large 
dorsal part, the longissimus capitis, arises from the transverse processes of the first 
four thoracic and the articular process of the last three or four cervical vertebrae, 
and ends with the splenius on the mastoid process of the temporal bone. The 
small ventral part, the longissimus atlantis, arises from the articular processes of 
the third, fourth, and fifth cervical vertebrae, and ends on the wing of the atlas. 
The other muscles present no striking differential features, but it may be noted 
that distinct interspinales are present. There are also small muscular bundles 
which lie beneath the multifidus in the back. These extend from the transverse 
process of one vertebra to the spine of the preceding one, and are appropriately 
termed the submultifidus. 
MUSCLES OF THE THORAX 
There are twelve pairs of levatores costarum. 
The external intercostal muscles do not occupy the spaces between the costal 
cartilages. 
The diaphragm is very strongly curved, and has a small tendinous center. 
The hiatus cesophageus is between the crura and is ventral to the twelfth thoracic 
vertebra. The costal part is attached to the lower (horizontal) part of the ninth 
