MUSCLES OF THE BACK. 181 



and fills up the concavity between the spinous and transverse pro- 

 cesses, the whole length of the vertebral column. 



The multifidus spines consists of a great number of fleshy fasciculi, 

 extending between the transverse and spinous processes of the verte- 

 brae, from the sacrum to the axis. Each fasciculus arises from a 

 transverse process, and is inserted into the spinous process of the 

 first or second vertebra above. 



Relations. By its- superficial surface with the longissimus dorsi, 

 semi-spinalis dorsi, and semi-spinalis colli. By its deep surface with 

 the arches and spinous processes of the vertebral column, and in the 

 cervical region with the ligamentum nuchse. 



The levatores costarum, twelve in number on each side, arise from 

 the transverse processes of the dorsal vertebras, and pass obliquely 

 outwards and downwards to be inserted into the rough surface be- 

 tween the tubercle and angle of the rib below them. The first of 

 these muscles arises from the transverse process of the last cervical 

 vertebra, and the last from that of the eleventh dorsal. 



Relations. By their superficial surface with the longissimus dorsi 

 and sacro-lumbalis. By their deep surface with the intercostal 

 muscles and ribs. 



The supra- spinales are little fleshy bands lying on the spinous 

 processes of the vertebra? in the cervical region. 



The inter-spinales are a succession of little pairs of muscles, lying 

 between the bifid tubercles of the spinous processes of the cervical 

 vertebrce. There are five pairs of these muscles ; the first being 

 situated between the axis and third vertebra, and the last between 

 the last cervical and first dorsal. 



The inter-transversales are also arranged in pairs, and pass be- 

 tween the bifid tubercles of the transverse processes of the cervical 

 vertebras. 



The inter-transversales, situated between the atlas and the occipi- 

 tal bone, are the recti laterales. They are sometimes found in the 

 lumbar regions. 



Relations. In front with the rectus anticus major and longus 

 colli ; and befiind by the muscles of the back of the neck. They are 

 separated from each other by the anterior branch of the' cervical 

 nerves, and by the vertebral artery and veins. 



With regard to the origin and insertion of the muscles of the back, 

 the student should be -informed that no regularity attends their at- 

 tachments. At the best, a knowledge of their exact connexions, 

 even were it possible to retain it, would be but a barren information, 

 if not absolutely injurious, as tending to exclude more valuable 

 learning. I have therefore endeavoured to arrange a plan, by which 

 they may be more easily recollected, by placing them in a tabular 

 form, that the student may see at a single glance, the origin and in- 

 sertion of each, and compare the natural grouping and' similarity of 

 attachments of the various layers. In this manner also their actions 

 will be better comprehended, and learnt with greater facility. 



