THE SKULL. 63 



margin of this cup, and which serves to deepen it, has been 

 destroyed by maceration ; /, the tuberosity terminating the 

 spine of the scapula, whence the flexor brachii originates. 



R, the humerus or arm bone ; g, the head of the bone ; 

 h, the smooth cartilaginous and synovial pulley over 

 which the tendon of the flexor brachii plays ; i, the external 

 trochanter of the humerus ; j, the inferior head of the 

 humerus ; k, the pit into which the ulna is received ; S, S, 

 the ulna, the top of which is termed the olecranon. 



T, T, the radius ; I, the head of the bone ; m, the inferior 

 head of the bone. 



U, U, the carpus or knee joint, consisting of two rows of 

 bones ; n, the trapezium, which give security to the great 

 flexors, and attachment to several of the lesser flexors of 

 the fore leg. 



V, V, the canon or shank bone ; o, o, the head of the 

 bone receiving the lower row of the bones of the knee ; 

 W, W, the splint bones ; p, the inferior head of the canon 

 bone. 



X, X, the sessamoid bones ; Y, Y, the large pastern bone ; 

 Z, Z, the small pastern bones ; P, the pedal or coffin bone. 



BONES OF THE HEAD. 



The head consists of two portions : one is simple, and is 

 merely the lower jaw {skel. B), which, in a prepared skeleton 

 of the head, is loose, and freely separates from the other 

 part. The top portion is more complex, and consists of 

 many pieces. At the back part of the skull {skel. h) is 

 the pole ; towards the sides are the cavities for the eyes 

 {skel. f) ; more forward are the openings, with long pas- 

 sages, for the nostrils {skel. d) ; and below is the roof of the 

 mouth, with half of the teeth {skel. a, b, c). 



THE SKULL. 



Several bones enter into the formation of this last-men- 

 tioned part, each of which have distinct anatomical names, 

 but, as all of them speedily become one mass, it will be 

 better if we consider this portion of the framew^ork as a 

 whole. The bones, however, are not united at the time 

 of birth ; w hence it is assumed that nature formed the skull 

 of several bits, to assist the expulsion of the foal from the 



