THE PHALAi 



The Phalanges of the Foot (Phalanges Digitomm Pedis). 



275 



The phalanges of the foot correspond, in number and general arrangement, 

 with those of the hand; there are two in the great toe, and three in each of the 

 other toes. They differ from them, however, in their size, the bodies being much 

 reduced in length, and, especially in the first row, laterally compressed. 



First Row. The body of each is compressed from side to side, convex above, 

 concave below. The base is concave; and the head presents a trochlear surface 

 for articulation with the second phalanx. 



Second Row. The phalanges of the second row are remarkably small and short, 

 but rather broader than those of the first row. 



The ungual phalanges, in form, resemble those of the fingers; but they are smaller 

 and are flattened from above downward ; each presents a broad base for articula- 

 tion with the corresponding bone of the second row, and an expanded distal 

 extremity for the support of the nail and end of the toe. 



TARSUS. 



One center for each bone, 

 except calcaneus 



OUTER FOUR METATARSALS. 



Two centers for each bone : 

 One for body 

 One Jar food 



Appears 10th year; 

 unites after puberty 



Appears 3rd year 

 } Unite 18th-20th year 



Appears 7th week 



PHALANGES. 



Two centers for each bone : 

 One for body 



One for metatarsal A PP- 6 - 7(A V r - 

 extremity Unite 17-18 yr. l ( 



App. 2-4 mo. - 

 App. 6th yr. 

 Unite 17-18 yr. { 

 App. 7th wk. 



FIG. 289. Plan of ossification of the foot. 



iculations. In the second, third, fourth, and fifth toes the phalanges of the first row articu- 

 late behind with the metatarsal bones, and in front with the second phalanges, which in their 

 turn articulate with the first and third: the ungual phalanges articulate with the second. 



Ossification of the Bones of the Foot (Fig. 289). The tarsal bones are each ossified from a 

 single center, excepting the calcaneus, which has an epiphysis for its posterior extremity. The 

 centers make their appearance in the following order: calcaneus at the sixth month of fetal life; 



