56 ANTHROPOLOGY. 
tinct muscles. It serves important purposes in moving the arm and in 
inspiration. | 
Pectoralis minor, flat and triangular, arises from the external surface and 
upper edge of the third, fourth, and fifth ribs, external to their cartilages, 
and is inserted into the inner and upper surface of the coracoid process of 
the scapula, near its anterior extremity, being here connected with the 
coraco-brachialis and short head of the biceps. Use: to draw the shoulder 
forwards, downwards, and upwards, also to assist the pectoralis major in 
elevating the ribs in inspiration. 
Subclavius, small and round, arises by a flat tendon from the cartilage of 
the first rib, external to the rhomboid or costo-clavicular ligament; it is 
inserted into the external half of the inferior surface of the clavicle. Its 
use is to draw the clavicle and shoulder forwards and downwards; also to 
elevate the first rib in inspiration, if the shoulder and clavicle be raised and! 
fixed. 
Serratus magnus, thin and broad, placed between the scapula and the ribs, 
arises by eight or nine fleshy strips from the eight or nine superior ribs; 
the fibres ascending are inserted between the subscapular, rhomboid, and 
levator anguli muscles into the base of the scapula, but particularly into the 
superior and inferior angles. It depresses the scapula and draws it forwards, 
raising the acromion process and the shoulder joint by rotating the scapula 
on its axis; it also plays an important part in inspiration. 
| Se aeks are twenty-two in number on each side, eleven external and 
eleven internal. The external commence at the transverse processes of the 
dorsal vertebre, arise from the inferior edge of each rib, and are inserted 
into the external lip of the superior edge of the rib beneath. The internal 
intercostals take an opposite direction and decussate the former; they com- 
mence at the sternum and are discontinued at the angles of the ribs. They 
arise from the inner lip of the lower edge of each cartilage and rib, and 
are inserted into the inner lip of the superior edge of the cartilage and rib 
beneath. Both laminze co-operate to raise the ribs, the first rib being fixed 
by the scaleni. 
Levatores costarum arise from the extremity of each dorsal transverse 
process, and are inserted into the upper edge of the rib. beneath, between 
its tubercle and angle. ‘T'hey serve to elevate the ribs. 
Trianguluris sterni, or sterno-costalis, arises from the posterior surface 
and edge of the lower part of the sternum, and from the xiphoid cartilage, 
and is inserted into the cartilages of the fourth, fifth, and sixth ribs. Use: 
to depress and draw back the cartilages of the ribs, so as to assist in 
expiration. 
Pl. 127, fig. 9", pectoralis major; *, pectoralis minor; *, subclavius; *, ser- 
ratus magnus; °*, intercostals. 
Pl. 124, fig. 15", pectoralis major. /%g. 17’, serratus magnus. 
. Pl. 125, fig. 198, subclavius; °, pectoralis minor; ", dentations of the 
serratus magnus. 
Pl. 126, fig. 20’*”°, intercostals. 
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