OSSIFICATION OF THE BONES OF THE FOOT. 



189 



tremity, in the metatarsal bone of the great toe and in the phalanges it is placed at the 

 proximal extremity. In the first metatarsal bone there is frequently, as in the first metacarpal 

 (see p. 109), also a second or distal epiphysis ; and in some instances a proximal epiphysis is 

 formed on the tuberosity of the fifth metatarsal bone (Gruber). In the metatarsal bones the 



Fig. 162. OSSIFICATION OF THE FONES OP THE FOOT. (R. Quain.) 



A, right foot of a fetus of six months ; the metatarsal bones and digital phalanges have each their 

 shafts ossified from their primaiy centres ; the tarsus is wholly cartilaginous, excepting the os calcis, 

 in which the nucleus of bone has just appeared. 



B, foot of a fostus of seven or eight months ; the astragalus shows a nucleus. 



C, from a child at birth ; the cuboid has begun to ossify. 



D, about a year old, showing a nucleus in the external cuneiform. 



E, in the third year ; ossification has reached the internal cuneiform. 



F, about four years old, showing ossification in the middle cuneiform and navicular bones, and in the 

 epiphyses of the metatarsal bones and phalanges. 



Gr, about the age of puberty ; ossification is nearly complete in the tarsal bones ; an epiphysis has 

 been formed on the tuberosity of the os calcis, and the epiphyses of the metatarsal bones and phalanges 

 are shown separate. 



1, nucleus of the os calcis ; 1* in G, the epiphysis of the os calcis ; 2, nucleus of the astragalus ; 3, of 

 the cuboid ; 4, of the external cuneiform ; 5, of the internal cuneiform ; 6, of the navicular ; 7, of the 

 middle cuneiform ; 8, metatarsal bones ; 8*, distal epiphysis of the second metatarsal bone ; 8', proximal 

 epiphysis of the first ; 9, first phalanx of the second toe ; 9*, proximal epiphysis of this phalanx ; 9', 

 that of the first phalanx of the great toe ; 10, second phalanx ; 10*, the epiphysis of this phalanx ; 

 10', epiphysis of the terminal phalanx of the great toe ; 11, terminal phalanx ; 11*, its epiphysis. 



nuclei of the shafts appear in the 8th or 9th week. The epiphyses appear from the 3rd to the 

 8th year, and unite with the shafts from the 18th to the 20th year. The nuclei of the shafts 

 of the phalanges appear in the 9th or 10th week. The epiphyses appear from the 4th to the 

 8th year, and unite with the shafts from the 19th to the 21st year. 



