OSSIFICATION OF THE BONES OF THE HAND 



9a 



epiphysis is formea from a distinct nucleus which appears in the 10th year. 

 This epiphysis is united to the shaft about the 17th year, while the inferior epi- 

 physis is only united to the shaft about the 20th year. 



Fiff. 87. 



Fig. 87 — Ossification op the Bones of the Hand. 



A, represents the state of the bones and cartilages at the period of birth. The carpus 

 is entirely cartilaginous. Each of the metacarpal bones and digital phalanges has its 

 shaft ossified. 



B, the state of the bones in a child at the end of the first year ; the os magnum and 

 unciform bone have begun to ossify. 



C, the condition about the third year. Centres of ossification are seen in the cuneiform 

 and in the proximal epiphysis of the first and the distal epiphysis of the other four meta- 

 carpal bones, and in the proximal epiphyses of the first row of phalanges. 



1), tlie condition at the fifth year. Centres have been formed in the trapezium, and 

 later in the semilunar bone, and in the middle and distal phalanges : (the figure does not 

 show them distinctly in the middle phalanges. ) 



E, tlie condition at about the ninth year. Centres have been formed in the scaphoid 

 and trapezoid bones, and the more developed epiphyses of the metacarpal bones and 

 phalanges are shown in the first and second digits separately. 



1, OS magnum ; 2, unciform ; 3, cuneiform ; 4, semilunar ; 5, trapezium ; 6, scaphoid ; 

 7, trapezoid ; 8, metacarpal bones, the ijrincipal pieces ; 8*, four metacarpal epiphyses ; 

 S', tliat of the thumb ; 9, the first range of phalanges ; 9*, their epiphyses ; 9', that of 

 the thumb ; 10, second range of phalanges ; 10', epiphyses of terminal phalanx of thumb, 

 11, tei'minal range of phalanges of the fingers j 11*, their epiphyses. 



H 2 



