A N A T 
face a round protuberance and folia are found, where the 
mufculus addudtor pollicis has its origin. On the external 
fide of this fame furface, there is a roun'd knob, covered 
with cartilage; immediately before which a fmooth fotfa 
may be obferved, in which the tendon of the percnceus 
primus runs obliquely acrofs the foot; and on the knob 
the thin flat cartilage proper to this mufcle plays; in place 
of which fometimes a bone is found. Mare externally 
than the knob, a rough hollow is made, for the ftrong li¬ 
gaments Aretched between .this bone and the oS calcis. 
Before, the furface of the os cuboidesis flat, fmooth, and 
ilightly divided into two planes, for fuftaining the os me- 
tatarli of the little toe, and of the toe next to it. 
Os cuneiforms externum is much of the fltape of a wedge, 
being broad and flat above, with long fides running oblique¬ 
ly downwards, and terminating in a fliarp edge. The up¬ 
per furface of this bone is an oblong fquare. The one 
behind is nearly a triangle, but not complete at the inte¬ 
rior angle, and is joined to the 6s naviculare. The exter¬ 
nal fide is half of it fmooth, for its conjundlion with the 
os cuboides. The other is a lcabrous hollow', and in its 
fuperior anterior angles a fmall Imooth imprefiion is made 
by the os metatarfi of the toe next to the little one. The 
internal fide of this bone is quadrangular, with the fore¬ 
part of its edge made flat and fmooth by the os metatarfi 
of the toe next to the great one, and the back-part is alfo 
fiat and fmooth where the os cuneiforpte medium is con¬ 
tiguous to it. The fore-part of this bone is an oblong 
triangle, for fuftaining the os metatarfi of the middle toe. 
Os cuneiforme medium or minimum is ftill more exaftly the 
fhape of a wedge than tire former. - Its upper part is 
fquare; its internal fide has a flat fmooth furface above 
and behind, for its conjunction with the following bone; 
with a fmall rough folia below ; and a conliderable fhare 
of it is rough and hollow. The external fide is fmooth and 
a little hollowed, where it is contiguous to the laft-defcri- 
bed bone. Behind, this bone is triangular, where it is arti¬ 
culated with the os naviculare ; and it is alfo triangular at 
its fore-part, where it is contiguous to the os metatarfi of 
the toe next to the great one. 
Os cuneiforme maximum or internum differs from the tw'o 
former in its fituation, being more oblique. Befides, its 
broad thick part is placed below, and the fmall thin point 
is above and outwards; while its under broad furface is 
concave, for allowing a fafe palfage to the flexor of the 
great toe. The furface of this os cuneiforme behind, 
where it is joined to the os naviculare, is hollow, fmooth, 
and of a circular figure below, but pointed above. The 
external fide confifts of two fmooth and flat furfaces, whofe 
direction is nearly at right angles with each other. With 
the pofterior, that runs obliquely from below forwards and 
upwards, the os cuneiforme minimum is joined; and with 
the anterior, whofe direction is longitudinal, the os meta¬ 
tarfi of the toe next to the great one is connected. The 
fore-part of this bone is femilunar, but flat and fmooth, 
forTuftaining the os metatarfi of the great toe. The in¬ 
ternal fide is fcabrous, with two remarkable tubercles be¬ 
low, from which the mufculus abduCtor pollicis rifes, and 
the tibialis anticus is inferred into its upper part. 
The feven bones of the larfus, when joined, are convex 
above, and leave a concavity below, for-lodging fafely 
the feveral mufcles, tendons, velfels, and nerves, that lie 
in the foie of the foot. In the recent fubject, their upper 
and lower furfaces are covered with ftrong ligaments, which 
adhere firmly to them; and all the bones are fo tightly 
connected by thefe and the other ligaments, which are fix¬ 
ed to the rough ridges and foffae mentioned in the preced¬ 
ing defeription of the particular bones, that notwithftand- 
ing the many furfaces covered with cartilage, fome of which 
are of the form of the very moveable articulations, no 
more motion is here allowed than only to prevent too great 
a ftiock of the fabric of the body in walking, leaping, See. 
by falling on too folid a bale ; which, if it were one conti¬ 
nued bone, would likewife be much more liable to be 
O M Y. 559 
broker.. Sprains occafion here, as in the wrift, great pain 
and obftinate tumours, which too often caufe carious bones. 
The melatarfus is comnofed of five bones, of which the 
os metatarfi pollicis is by far the thickcft and ftrongeft, as 
having much the greatelt weight to fuftain. Its bale is 
oblong, irregularly concave, and of a femilunar figure, to 
be adapted to the os cuneiforme maximum. The inferior 
edge of this bale is a little prominent and rough, where 
the tendon of the peronams primus mufcle is inferted. On 
its outlide an oblique circular deprefiion is, made by the 
fecond metatarfal bone. Its round head has generally on 
its fore-part a middle ridge, and two oblong cavities, for 
the olfa fefamoidea. Os metatarfi of the fecond toe, is the 
longeft of the five, with a triangular bale fupported by the 
os cuneiforme medium and the external fide produced in¬ 
to a procefs; the end of which is an oblique imooth plane, 
joined to the os cuneiform.e externum. Near the internal 
edge of the bafe, this bone has two fmall deprellions, made 
by the os cuneiforme maximum, between which is a rough 
cavity. Os metatarfi of the middle toe, is the fecond in 
length. Its bafe, fupported by the os cuneiforme exter¬ 
num, is triangular, but ilanting outwards, where it ends 
in a fliarp-pointed little procefs; and the angle below is 
not completed. The internal fide of this bafe is adapted 
to the preceding bone; and tire external fide has two 
fmooth furfaces covered with cartilage. Os metatarfi of 
the fourth toe is near as long as the former, with a trian¬ 
gular flanting bale joined to the os cuboides, and made 
round at its external angle ; having one hollow fmooth fur- 
face on tire outlide, where it is preffed upon by the fol¬ 
lowing bone; and two on the internal fide, correfponding 
to the former bone; behind which is a long narrow fur¬ 
face impreffed by the os cuneiforme externum. Os meta¬ 
tarfi of the little toe is the Ihorteft, fituated with its two 
flat fides above and below, and with the ridges laterally. 
The bafe of it, part of which reds on the os cuboides, is 
very large, tuberous, and produced into a long-pointed 
procefs externally, where part of the abdubtor minimi di¬ 
git! is fixed; and into its upper part the peronaeus fecim- 
dus is inferted. Its infide has a flat conoidal furface, 
where it is contiguous to the preceding bone. When we 
ftand, the fore-ends of thefe metatarfal bones, and the os 
calcis, are our only fupporters; and therefore it is necef- 
f'ary that they ihould be ftrong, and fliould have a confined 
motion. 
The bones of the toes are nearly fimilar to thofe of the 
thumb and fingers; particularly the two of the great toe 
are precifely formed as the two laft of the thumb ; only 
their polition, in refpefl: of the other toes, is not oblique; 
and they are proportionally much ftronger, becaufe they 
are l'ubjesfted to a greater force; for they fuftain the force 
with which our bodies are pufhed forwards by the foot at 
every ftep we make. The three bones in each of the other 
four toes, compared to thofe of the fingers, differ from 
them in thefe particulars: They are lefs and fmaller in 
proportion to their lengths; their bafes are much larger 
than their anterior ends; their bodies are more narrow 
above than below, and flatter on the fides; and the firft 
phalanx is proportionally much longer titan the bones of 
the fecond and third, which are very Ihort. Of the four, 
the toe next to the great one has the largeft bones in all 
dimenfions, and more externally the toes are lefs. The 
little toe, and frequently that next to it, have the fecond 
and third bones intimately united into one ; which may be 
owing to their little motion, and the great preffure they 
are fubjebl to. 
The only bones now remaining to complete the deferip¬ 
tion of the Ikeleton, are the fmall ones which are found at 
the joints of the fingers and toes, and in iome other parts, 
called ojfa fefamoidea. Thefe are of very different figures 
and lizes, though they are generally faid to relemble the 
feed of the fefamum. They feem to be nothing elfe than 
the ligaments of the articulations, or the firm tendons of 
ftrong mufcles, or both, become bony by the compreflion 
w hiefi. 
