: .i.\Ti-:nnnt 



>'. The (iiil'-rinr or ir/v/.W nn-jl is the thinnest of the three. The 

 or '/"/W (//;// is thick ami tuberous. Tin- inferior or humeral 

 itni/l'' is the most voluminous, and is separated from the, remainder of tho 

 hone by a slight constriction, which constitutes tlie c<7.- of tho scapula. It 

 exhil.it>: 1. The ;// //"/</ cnrihj, an oval diarthrodial surl'ac, . ( -\cavated to ft 

 slight extent to receive the hcail of the liumerus, notched on the inner side, 

 and bearing on the external margin of the ridge which surrounds it a small 

 tulxTcle of insertion; 2, The coracoid process, situated in front, and at ft 

 11 distance from tho glenoid cavity. This is a large cminem- 

 in which may bo distinguished two parts: tho base, ft thick rugged process; 

 and the tuiiniitit, a kind of beak curved inwards. 



Xfrii<-lnre and development. Like all the wide bones, tho scapula is 

 formed of two compact lamella; separated by spongy tissue. The latter is 

 v. ry scanty towards the centres of the supra and iufraspinous foss;e, where it 

 is nfteii alt _' tlier wanting; it is most abundant in 

 the angles. The scapula is developed from two centres 

 of ossification, one of which forms the coracoid pro- 

 cess. 



AUM. 

 This region has only one bono, the humerus. 



Humerus. 



Tho liumerus is a long single bone, situated between 

 tho scapula and the bone of the fore-arm, in an oblique 

 direction downwards and backwards. Like all the long 

 bones, it oilers for study a body and two extremities. 



Body. The body of the humerus looks as if it 

 had been twisted on itself from within to without in 

 . '.erior extremity, and from without to within at 

 the opposite end. It is irregularly prismatic, and is 

 divided into four faces. The anterior face, wider 

 than below, has in its middle and inferior por- 

 muscular imprints. The posterior, smooth 

 and rounded from one side to the other, becomes 

 -ibly confounded with the neighbouring faces. 

 The ,j-t>rnal is excavated by a wide furrow, which 

 entirely occupies it, and turns round tho bone ob- 

 liquely from above to below and behind to before; 

 it is to the presence of this channel that tho huinerus AS :;XAI vn:w 



a its apparent twist, and it is in consequence OF lacin m MI 

 jnated the furrow of torsion of tho body of the 1, TnxhliMi- or 



liumerus. 



This furrow is separated from the anterior face 



salient border, the anterior crest of the furrmo 



inn, whieh ends inferiorly above tho coronoid 

 . and superiorly, towards tho upper third of tho 

 bone, by tho imprint, or deltoid tuberosily. This is a 

 roughened, very prominent eminence, flattened before 

 and behind, ami inclining towards the furrow of 

 torsion; by its suj>erior extremity it gives origin to 

 u curved line which is carried backwards to join tho 

 base of the articular h- .id. Near the inferior extremity, 1 and 



: -'. Hxternal or 

 'Irlt.pM tiilHTiit\ 



r :irtirul:ir siir- 

 !. Kxti-rnal tul*-r- 

 Siinft HI-IM..IV with 

 its t wi>tri( fuiT.iu : 

 Aiti<ml:ir <>r tr<M-hli-:ir 

 coixlyles; 8, Ulunr fos* 

 witli a siili-u-; '.i. Fossa 

 for tin- iuM-rti<>ii of the 

 \tiTii.il Literal 



Illrllt. 



