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 stemo-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. primse costse) 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 coUi 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 vertebrse, from the ligamentum nuchae, and the median raphe. It has 

 four oblique tendinous intersections. The complexus major arises on the trans- 

 "\-erse processes of the first three or four thoracic vertebrae 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 oesophageus 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 



