THE MORSELS FOOT. 
101 
face is convex and pierced with foramina for the passage of veins 
and slightly overlays the Surface of the bone of the foot. It is 
separated from the skin by a very rich vascular plexus. The 
internal face, concave, is hollowed by vascular grooves and covers, 
forward the articulation of the foot and the cul do sac of the 
synovial sac which protrudes between the two lateral ligaments of 
that joint. Downwards and backwards it is united to the plantar 
cushion, either by continuity of tissue, as near the inferior border, 
or by fibrous bands running from one to the other. The superior 
border, either convex or straight, is thin, and separated from the 
posterior by an-obtuse angle in front of which it presents a deep 
notch for the passage of the blood vessels and nerves. The in¬ 
ferior border is attached, forward, to - the basilar and retrosal 
processes of the os pedis. Behind this it reflects in wards,to continue 
to the inferior face of the plantar cushions. The posterior border, 
oblique, backwards and downwards, is slightly convex and unites 
with the preceding. The anterior border, oblique in the same 
direction, is more intimately united to the anterior lateral liga¬ 
ment of the articulation and can be separated from it only by arti¬ 
ficial dissection. It sends upon this ligament and upon the an¬ 
terior extensor of the phalanx, a fibrous extension, which unites 
with that of the opposite side. 
[n their structure the fibro-cartilages comprehend a mixture of 
fibrous and cartilaginous tissue, a mixture which is far from being 
homogenous and even in the various parts. The more it is ex¬ 
amined forwards and near the base, the more its substance is seen 
to resemble that of cartilages proper, being white, flexible, brittle, 
and homogenous. Towards its posterior part it loses its charac¬ 
ters of liomogenity, becomes less brittle and presents in its thick¬ 
ness a greater amount of fibrous texture. More posteriorly 
again, the fibro-cartilagmous structure is more marked. By 
close attention it seems to show cartilaginous nuclei, isolated, and 
surrounded with an entirely fibrous substance; and again, at its 
posterior extremity it becomes fibro-greasy with much cellular 
tissue and unites with the plantar cushion. The vitality of the 
cartilage is in inverse ratio with its density and consequently is 
greater in its posterior part than towards the base and its anterior 
