i5° 



ATLAS AND TEXT-BOOK OF HUMAN ANATOMY. 



Fig. 239. — The superficial layer of the long muscles of the back. 

 All the flat muscles, the splenii and the iliocostalis of the left side have been removed. 



The longissimus, the inner portion of the sacrospinalis, is composed of three subdivisions 

 — the lon gissimus dorji , ceryicis., and japitis. 



Rotatores longi '"--.. . 



Rotatores breves 



Multifidus 



y Transverse processes 



Semispinalis 



Spinous process *-'--^^ 



Fig. 240. — Diagram of the arrangement of the various portions of the transverso-spinalis (semispinalis, multifidus, 



rotatores). 



The longissimus dorsi (Figs. 239 and 241), in addition to its common origin with the ilio- 

 costalis lumborum, receives accessor}' origins from the transverse processes of the lower thoracic 

 vertebrae. Its insertions are arranged in an internal and in an external series, and are. partly 



