90 



TBE BONES. 



elevated, is followed by an acromion whose extremity reaches to ^^°;^^*« «^P"1°; 

 humeral articulation. The latter is separated from the ^e^amder of the spme^by a 

 constriction called the pedicle of the acromion. The «»acGid process is yoli^nnn^^^^ 

 resembles a semi-flexed fiBger. T be clavicle extends from the '»'=^™J*°^^?„f ^^7^ 

 it is flattened above and below, and flexed like an italic S. This inflexion ot tne 

 clavmleismore^pronou^^^^^^^^^ „ die .ysi, 



is prism'^aHc and'divi^rbll int^o three faces : the deltoid i^print has f e form of a^ wUb 

 its point directed downwards. The voluminous articular head is turned inwards . tna 



Fig. 55. 



Fig. 56. 



I 4 /. 



' Vr 



HITMAN arm-bones; FRONT VIEW. 

 1, Shaft of ulna ; 2, Greater sigmoid 

 notch; 3, Lesser sigmoid notch; 4 Ole- 

 cranon process ; 5, Coronoid process ; 6j 

 Nutrient foramen ; 7, Ridges for inser- 

 tion of interosseous membrane; 8, CapH 

 talum ulnse; 9, Styloid process; 10, 

 Shaft, of radius ; 11, Its head ; 12, Its 

 neck ; 13, Its tuberosity ; 14, Oblique 

 line; 15, Lower end of bone; 16, Styloid 

 process.^ 



EIGHT HUMAN HTJMERUS ; ANTEEIOK 

 SURFACE. 

 1, Shaft ; 2, Head ; 3, Neck ; 4, Greater 

 tuberosity; 5, Lesser tubevosity ; 6, Bici- 

 pital groove ; 7, Interior bicipital groove ; 

 8, Posterior bicipital ridge ; 9, Rough sur- 

 face for insertion of deltoid ; 10, Nutrient 

 foramen; 11, Eminentia capitata; 12, 

 Trochlea; 13, External condyle; 14, In- 

 ternal condyle; 15, External condyloid 

 ridge ; 16, Internal condyloid ridge ; 17, 

 Fossa for the coronoid process of ulna. 



bicipital groove is single, and looks outwards. The inferior articular surface resembles 

 that of animals, except that the condyle is more distinct. 



C. FoKE-AKM. — The two bones of the fore-arm, as we have already seen, only articu- 

 late by their extremities ; they are sepaiatecj from one another in their middle part. 

 The superior extremity of the radius corresponds to the condyle of the humerus ; that of 

 the ulna articulates with the humeral trochlea. The coronoid process belongs to the 

 ulna. At the lower extremity of the fore-arm it is remarked : 1, That the radius cor- 

 responds to the greater portion of the carpus, -while the ulna only articulates with the 

 pyramidalis ; 2, That the radio-carpal articulation is protected outwardly and inwardly 

 by two small osseousj prolongations, the styloid processes of the ulna and radius. 



D. Hand. — 1. Carpus. — The carpus of Man is composed of eight bones — four in each 



