| OCR Text |
Show 18b5.] MYOLOGY OF THE WATER-OPOSSUM. 7 The anterior few fibres are inserted into base of spine, the rest by a broad muscular mass into base of scapula, being embraced in posterior half by serratus magnus. Acromio-trachelien (omo-atlantic).-Arises by a flat tendon from anterior arch of atlas, and by a small accessory slip from basioccipital. The greater part of the muscle is inserted into dorsal third of spine of scapula, whilst a thin slip, leaving muscle in its lower third, crosses insertion of omohyoid, and is inserted into base of scapula in close connection with inner portion of serratus magnus. Cleido-occipital.-Arises near middle of clavicle by muscular fibres, and is inserted into occipital crest internal to cleido-mastoid, its posterior fibres being continuous with trapezius for half an inch. Its anterior fibres are just united with cleido-mastoid at their insertion. Cleido-mastoid.-Overlain by sterno-mastoid except just at its origin. Arises from front of clavicle at its sternal end by fleshy fibres. It forms a broad, flat muscle, inserted by a rounded mass into occiput between sterno-mastoid and digastric, and by coarse fasciculi into occipital crest for its outer half. Sterno-mastoid,-Arises from front of manubrium sterni by tendinous and fleshy fibres, close to its fellow of opposite side. It forms a broad fleshy belly, inserted by a tendon into front of mastoid process just behind external auditory meatus. It is continuous just at its insertion with cleido-mastoid. Trapezius.-This muscle was much damaged. It apparently arises from occipital protuberance, its anterior fibres being continuous with posterior fibres of cleido-occipital, from spines of cervical and dorsal vertebrae. Its anterior and middle fibres are inserted into whole length of spine of scapula, whilst its posterior ones pass forwards to be inserted into the spine at its dorsal part. Latissimus dorsi.-Arises from spinous processes of dorsal vertebrae, and from lumbar fascia which attaches it to lumbar vertebrae and crest of ilium. Inserted by narrow tendon into inner lip of bicipital groove of humerus. Dorsi epitroch/ear.-A thin muscular slip arising from outer surface of latissimus dorsi by tendinous fibres, and inserted into fascia on inner side of arm which attaches it to olecranon. Serratus magnus.-Arises by thirteen digitations from posterior six cervical transverse processes, closely connected with insertion of scalenus, and from outer surface of first seven ribs. The anterior fibres are inserted into inner lip of base of scapula, whilst the posterior digitations curve round to outer lip of base, embracing insertion of rhomboideus. Subclavius.-Arises from cartilage of first rib and is inserted into posterior border of clavicle at its outer half, a few of its inner fibres being continuous with the following portion, which arises by muscular fibres from the posterior border of clavicle at its outer two thirds, and is inserted by thin tendinous fibres into anterior border of acromion. Pectoralis major.- Consists of two portions : - a , a large triangular |
