96 



THE OSTEOLOGY AND MYOLOGY 



entirely fleshy, arising from the lower border of the side of the thyroid, passing inward 

 and upward, and inserted into nearly the whole of the lower border of the hyoid. 



Besides those that pass to the shoulder, the muscles of the anterior vertebral group 

 are the three recti of the head, the longus colli and the scaleni. 



Rectus capitis anticus major. — This capital prolongation of the longus colli is large 

 and conspicuous, and tolerably distinct from the cervical portion, to which the latter 

 name is usually restricted. It arises by attenuated slips from the transverse processes 

 of all the cervical vertebra); these slips lying external to those of the longus colli 

 proper. They unite, frequently with slight tendinous constrictions, into a stout, some- 

 what cylindrical mass, that converges to come into apposition with its fellow over the 

 atlas, and is inserted fleshy into the greater part of the basioccipital. 



Rectus capitis a?iticus minor. — Smallest of the three recti, and completely hidden by 

 the overlying major, from which, however, it is perfectly distinct. It arises fleshy from 

 the whole anterior border of the ring of the atlas, passes directly forward over the 

 condyle and is inserted fleshy, beside its fellow, into the basioccipital at the border of 

 the foramen and root of the condyle. 



Rectus lateralis.— A small, but perfectly distinct fasciculus, lying external to the last, 

 separating it from the obliquus superior. It arises from the transverse process of the atlas, 

 and runs obliquely inward and forward to the basioccipital. 



Longus colli. — Occupies the front of the vertebral column from the atlas to the fourth 

 dorsal vertebra, arising by slips from the transverse processes of all but the first cervical, 

 and attached to the bodies of the vertebrae as it passes over them. In most of its course 

 it is in relation to its fellow, mesial, and to the rectus major external. Above, the two 

 muscles, or halves of the muscle, converge to meet in a point on the median line of the 

 atlas. The large volume of muscle upon the front of the spin.'d column and basilar 

 process has evident relation to such a flexion of the head and body as is necessary, for 

 example, in attending to the pouch, or regaining foothold after suspension by the tail. 



Scaleni. — I have never been able to demonstrate three ; the second one — the medius — 

 cannot be found at all, and the first (anticus) is small and blended Avith the third (posticus); 

 the latter is large and conspicuous. The S. anticus, when tolerably distinct, arises from the 

 most lateral points of the transverse processes of two or three lower cervicals, and is 

 inserted into the first rib, near the middle of the latter, just in front of a slip from the 

 serratus magnus. The S. posticus is perfectly distinct as to the thoracic portion. It arises 

 from the transverse processes of all the cervicals as high up as the origin of the levator 

 scapuhp. separating this from the rectus capitis major. Widening and flattening as it 

 descends, it passes outward as well as downward, behind the subclavius, to be inserted by 

 three, broad, flat, fleshy digitations into the posterior borders of the second, third and fourth 

 ribs, near their middle, just over the corresponding digitations of the serratus, and behind 

 the outer border of the thoracic part of the rectus abdominis. It is a direct levator costa- 

 rum and flexor cervicis. Its cervical origins are sometimes blended with those of the leva- 

 tor anguli scapulae for a little distance. 



The muscles upon the back of the neck are the same as those found on this part of the 

 human body. The only notable differences lie in their relative size and configuration ; and 

 even in these respects the discrepancy is not great, except in the instances of the rectus 

 capitis posticus major, and obliquus capitis inferior, both of which are of great proportional 



