244 OSTEOLOGY. 
being developed from secondary centres which appear from two to four years after birth, 
fusion with the shaft being usually completed about the eighteenth year. In striking 
contrast to this is the mode of ossification of the first metatarsal. From its primary 
centre the head and shaft is developed; the secondary centre appears at its base about 
the second or third year, and fuses with the shaft about eighteen. In this respect, there- 
fore, the metatarsal bone of the great toe resembles in its mode of development the 
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phalanges. Mayet, however (Bull. Soc. Anat. Paris, 1895), describes the occurrence of 
two ossific centres in the proximal epiphysis. These fuse early, and he considers that the 
one represents the metatarsal element, whilst the other may be regarded as phalangeal in 
its origin. 
THE PHALANGES. 
The phalanges of the toes (phalanges digitorum pedis) differ from those of the 
fingers in the striking reduction of their size, and in the case of the bones of the 
first row, in the lateral compression of their shafts. Each 
toe is provided normally with three phalanges, except the 
great toe, which has only two. In their general configura- 
tion, and in the arrangement of their articular facets, they 
resemble the digital phalanges, though, owing to the re- 
duction in their size, the shafts, particularly those of the 
second row, are often so compressed longitudinally as to 
reduce the bone to a mere nodule. The proximal end of 
each of the bones of the first row is proportionately large, 
and is provided with a simple hollow in which the head of 
the metatarsal bone rests; the distal ends are furnished with 
condyloid surfaces. The proximal extremities of the second 
row are each provided with two small concavities, separated 
by a slight ridge for articulation with the condyles of the 
first row. The joint between the second. and third row 
displays the same arrangement— the third, terminal or 
ungual phalanx, being easily distinguished by the spatula- 
shaped surface at its extremity on which the bed of the nail 
is supported. 
Pre Ms apica sdcirese The phalanges of the great toe, two in number, differ 
or tHe Tors (dorsal from the others in their size and length. Into the base of 
aspect). the first phalanx are inserted the short muscles of the great 
toe, whilst the second phalanx receives on its plantar 
aspect the insertion of the flexor longus hallucis muscle, the tendon of the ex- 
tensor longus hallucis being inserted into the dorsal aspect. 
OR TERMINAL 
PHALANX 
METATARSAL 
Architecture.—In their general structure they resemble the bones of the fingers. 
Variations.—It is not uncommon to meet with fusion of the second and third phalanges, 
particularly in the fifth, less frequently in the fourth, and occasionally in the second and third 
toes. The union of the phalangeal elements has been observed in the foetus as well as the adult 
(Phitzner). The proportionate length of the phalanges varies much; in some cases the ungual 
phalanges are of fair size, the bones of the second row being mere nodules, whilst in other instances 
the reduction in size of the terminal phalanges is most marked. 
Ossification.—EKach phalanx is developed from two. centres—one primary for the 
shaft and distal extremity, the other for the epiphysis on the proximal end. The primary 
centres for the ungual phalanges are the first to appear, commencing to ossify from the 
eleventh to the twelfth week of foetal life. The centre for the ungual phalanx of the great 
toe makes its appearance before that of its corresponding metatarsal bone. The primary 
centres for the phalanges of the first row appear from the fourteenth to the sixteenth 
week. The primary centres for the middle phalanges of the second and third toes begin 
to ossify about the sixth month, those for the fourth and fifth toes not till later—the 
shaft of the middle phalanx of the fourth toe being frequently cartilaginous at birth, the 
normal condition in the case of the fifth toe (Lambertz). The proximal epiphyses do not 
begin to ossify until about the fourth year, and are usually fused with the diaphyses about 
the age of sixteen or eighteen. Union between the shafts and epiphyses of the first row 
precedes that of the second and third rows. 
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