1 5 2 Mufcles of the [Book IX* 



The trapezius arifes by a ftrong round tendon, 

 from the middle of the os occipitis, and from a rough 

 curved line, which extends thence towards the ma- 

 ftoid procefs of the temporal bone. It proceeds 

 downwards along the nape of the neck, is attached 

 to the fpinous procefies of all the vertebrae of the 

 back, and the two loweft of the neck, and is. alfo 

 firmly connected by the intervention of a tendon- to 

 its fellow of the oppofite fide. It is inferted into the 

 pofterior part of the clavicle, the acromion, and almoft 

 all the fpine of the fcapula. It moves the fcapula 

 either obliquely upwards, directly backwards, or ob- 

 liquely downwards, according as its different parts are 

 called into action. 



The latiflimus dorfi arifes, by a broad thin ten- 

 don, from the ppfterior part of the fpine of the os 

 ileum, from the fpinous procefies of the os facrum, 

 loins, and feven inferior of the back, and from -three 

 or four of the lower ribs j its fibres converging pafs 

 over the inferior angle of the fcapula, are collected 

 into a -flat cord in the axilla, and inferted into the os 

 humeri. Its action is to pull the arm downwards and 

 backwards, and to roll the os humeri. 



The fecond layer of mufcles confifts of three pair* 

 two on the back and one on the neck. On the back 

 are feated the ferratus pofticus inferior. This mufcle 

 originates from the fpinous procefles of the two infe- 

 rior of the back and three iuperior vertebrse of the 

 loins, is initrted into the four loweft ribs, which it 

 draws downwards, and is therefore a mufcle of ex- 

 piration. 



The rhomboideus proceeds from the fpinous pro- 

 ceflcs of the five fuperior vertebras of the back and 

 three inferior of the neck, and is inferted into the bafe 



ef 



