362 THE MUSCLES OF THE PIG 
The longissimus costarum extends to the wing of the atlas. 
The spinalis et semispinalis can be separated without much difficulty from 
the longissimus dorsi, the division from the common mass of the loins beginning 
about the first lumbar vertebra. 
The multifidus resembles that of the horse. 
Interspinales are present, as well as distinct intertransversales of the back 
and loins. 
MUSCLES OF THE TAIL 
The dorsal and lateral sacro-coccygei arise as far forward as the last lumbar 
vertebra. Gurlt explains the twist of the tail as being due to the spiral arrangement 
of the insertions of the tendons. 
MUSCLES OF THE THORACIC LIMB 
MUSCLES OF THE SHOULDER GIRDLE 
The trapezius is very wide, its line of origin extending from the occipital bone 
to the tenth thoracic vertebra. There is no clear division between its two parts, 
which are both inserted into the scapular spine. 
The omo-transversarius resembles that of the ox. 
The rhomboideus consists of three parts. The cervical part (Rhomboideus 
cervicalis) is greatly developed, its origin extending from the second cervical to the 
sixth thoracic vertebra. The cephalic part (Rhomboideus capitis) arises with the 
splenius on the occipital bone, and is inserted with the cervical part. The thoracic 
part (Rhomboideus thoracalis) extends as far back as the ninth or tenth thoracic 
vertebra. 
The latissimus dorsi is attached to the four ribs preceding the last. It is 
inserted into the medial tuberosity of the humerus. 
The brachiocephalicus divides into two parts, the cleido-mastoideus and 
cleido-occipitalis, which arise on the mastoid process and nuchal crest respectively, 
and unite at the fibrous vestige of the clavicle. 
The anterior superficial pectoral muscle is thin. The posterior superficial pec- 
toral muscle is divided into two parts, one of which ends on the humerus, the other 
on the fascia of the forearm. The anterior deep pectoral muscle resembles that of 
the horse, but its origin does not extend behind the first two chondro-sternal joints. 
The posterior deep pectoral muscle is very long. 
The cervical part of the serratus ventralis is greatly developed, its origin ex- 
tending from the wing of the atlas to the upper part of the fifth rib, and passing 
under the thoracic part; the latter resembles that of the ox. 
MUSCLES OF THE SHOULDER 
The deltoid is undivided; it arises from the aponeurosis covering the infra- 
spinatus, and it ends largely on the deltoid ridge, but partly on the fascia of the arm. 
The supraspinatus is large; it has a small attachment to the medial tuberosity | 
and ends chiefly on the lateral tuberosity of the humerus. There is a bursa between 
the tendon and the anterior part of the lateral tuberosity. 
The infraspinatus is wide; it is inserted into a depression below the posterior | 
division of the lateral tuberosity. There is a bursa between the tendon and the | 
tuberosity. 
The teres minor is large and rounded; it ends on a tubercle between the 
lateral and deltoid tuberosities of the humerus. 
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