ANATOMY. 
From behind the uppermoft of the two anterior fpinal 
proceflTes, in fuch bones as are ftrongly marked by the 
mufcles, a femicircular ridge is extended to the hollow 
paflage of the fciatic nerve. Between the fpine and this 
ridge, the gluteus medius takes its rife. Immediately 
from above the lowed of the anterior fpinal precedes, a 
fecond ridge is flretched to the niche. Between this and 
the former ridge, the glutreus minimus has its origin. On 
the outfide of the poflerior fpinal procelfgs, the dorfum of 
the os ilium is flat and rough, where part of the mufculus 
glutseus maximus and pyriformis riles. The internal fur- 
face of the os ilium is concave in its breaded fore-part, 
where the internal iliac mufcle has its origin, and where 
fome fhare of the inteflinum ilium and colon is lodged. 
From this large hollow, a fmall fmuofity is continued ob¬ 
liquely forwards, at the inlide of the inferior fpinal pro- 
cefs, where part of the pfoas and fiiacus mufcles, with 
the crural vefl'ds and nerves, pafs. The large concavity 
is bounded below by a Iharp ridge, which runs from be¬ 
hind forwards; and, being continued with fuch another 
ridge of the os pubis, forms a line of partition between 
the abdomen and pelvis. Into this ridge the broad ten¬ 
don of the pfoas parvus is inferted. 
The os ifchium , or hip-bone , is of a middle bulk between 
the two other parts of the os innominatum, is fituated 
lowed of the three, and is of a very irregular figure. Its 
extent might be marked by a horizontal line drawn near¬ 
ly through the middle of the acetabulum. From the up¬ 
per thick part of the os ifchium, a fharp procefs, called 
by fome authors fpinous , dands out backwards, from which 
chiefly the mufculus coccygasus and fuperior gemellus, 
and part of the levator an;, rife; and the anterior or in¬ 
ternal facrofciatic ligament is fixed to it. Between the up¬ 
per part of this ligament and the bones, it was formerly 
obferved that the pyriform mufcle, the poderior crural 
velfels, and the fciatic nerve, pafs out of the pelvis. Im¬ 
mediately below this procefs, a fmuofity is formed for the 
tendon of the mufculus obturator interims. Below the fi- 
nuofity for the obturator mufcle, is the great knob or tu- 
berofity, covered with cartilage or tendon. The upper 
part of the tuberolity gives rife to the inferior gemellus 
mufcle. To a ridge at the infide of this the external or 
poderior facrofciatic ligament is fo fixed, that between it, 
the internal ligament, and the fmuofity of the os ifchium, 
a paflage is left for the internal obturator mufcle. The 
upper thick fmooth part of the tuber, called by fome its 
dorfum , has two oblique impreflions on it. The inner one 
gives origin to the long head of the biceps flexor tibiae, and 
feminervofus mufcles; and the femimembranofus rifes 
from the exterior one, which reaches higher and nearer 
the acetabulum than the other. The lower, thinner, more 
fcabrous, part of the knob which bends forwards, is alfo 
marked w ith two flat furfaces; whereof the internal is 
what we lean upon in fitting, and the external gives rife 
to the larged head of the triceps addudlor femoris. Be¬ 
tween the external margin of the tuberofity and the great 
hole of the os innominatum, there is frequently an obtufe 
ridge extended down from the acetabulum, which gives 
origin to the quadratus femoris. As the tuber advances 
forwards, it becomes fmaller, and is rough, for the origin 
of the mufculus tranfverfalis and eredfor penis. The 
fmall leg of it, which mounts upwards to join the os pu¬ 
bis, is rough and prominent at its edge, where the two 
lower heads of the triceps or quadriceps addudtor femoris 
take their rife. 
The os pubis, or Jhartrbone, is the lead of the three parts 
of the os innominatum, and is placed at the upper fore¬ 
part of it. The thick larged part of this bone is employ¬ 
ed in forming the acetabulum; from which, becoming 
much fmaller, it is flretched inwards to its fellow of the 
other fide, where it again grows larger, and fends a fmall 
branch downwards to join the end of the fmall leg of the 
os ifchium. The upper fore-part of each os pubis is tu¬ 
berous and rough where the mufculus redtus and pyrami- 
dalis are inferted. From this a ridge is extended along 
Vo L. 1 . No. 35, 
the upper edge of the bone, in a continued line with fuch 
another of the os ilium, which divides the abdomen and 
pelvis. The ligament of Fallopius is fixed to the inter¬ 
na! end of this ridge, and the fmooth hollow below it is 
made by the pfoas and iliacus interims mufcles palling with 
the anterior crural velfels and nerves behind the ligament. 
Some way below the former ridge, another is extended 
from the tuberous part of the os pubis downwards and 
outwards towards the acetabulum; between thefe two 
ridges the bone is hollow and fmooth, for lodging the 
head of the peclineus mufcle 1 . 
Between the os ifchium and pubis a very large irregular 
hole is left, which, from its refemblance to a door or 
fliield, lias been called ihyroides. This hole is filled up, in 
a recent fubjeef, with a flrong ligamentous membrane, that 
adheres very firmly to its circumference. From this mem¬ 
brane chiefly the two obturator mufcles, external and in¬ 
ternal, take their rife. The great dallgn of this hole, be- 
fides rendering the bone lighter, is to allow a flrong ori¬ 
gin to the obturator mufcles. The bowels fometimes 
make their way through the niche at the upper part of 
this thyroid hole ; which caufes a hernia in this place. 
In the external furface of the o(fa innominata, near the 
outfide of the great hole, a large deep cavity is formed 
by all the three bones conjuncHy. The brims of this ca¬ 
vity are very high, and are flill much more enlarged by 
the ligamentous cartilage, with which they are tipped in 
a recent fiibjedt. From this form of the cavity it has 
been called acetabulum-, and for a diflinguifliing character 
the name of the bone that conftitutes die largefl (hare of 
it is added: therefore acetabulum ojjis ifehii is the name this 
cavity commonly bears. Round the bafe of the fupercilia 
the bone is-rough and unequal, where the capfular liga¬ 
ment of the articulation is fixed. Befides the difference 
in the height of the brims, the acetabulum is otherwife 
unequal; for the lower internal part of it is deprefled be¬ 
low the cartilaginous furface of the upper part, and is not 
covered with cartilage; into the upper part of this de- 
preflion, where it is deepefl and of a femilunar form, the 
ligament of the thigh-bone, commonly, though improper¬ 
ly called the round one, is inferted; while, in its more fu- 
perficial lower part, the large mucilaginous gland of this 
joint is lodged. 
The offa innominata are joined at their back-part to each 
fide of the os facrum by a fort of future, with a very thin 
intervening cartilage, which ferves as fo much glue to ce¬ 
ment thofe bones together; and flrong ligaments go from 
the circumference of this unequal furface, to connefit them 
more firmly. The ofla innominata are connected together 
at their fore-part by the ligamentous cartilage interpofed 
between the two ofla pubis. Thefe bones can therefore 
have no motion in a natural ftate, except what is common 
to the trunk of the body, or to the os facrum. 
Thus the pelvis lias a large cavity above where it is con¬ 
tinued with the abdomen; is flrongly fenced by bones on 
the fides, back, and forepart; and appears with a wide 
opening below, in the fkeleton ; but, in a recent fubjedt, a 
conliderable part of the opening is filled by the facrofciatic- 
ligaments, pyriform, internal obturator, levatoresani, ge- 
mini, and coccygaei mufcles, which fupport and protedi 
the contained parts better than bones could have done; fo 
that fpace is only left at the lowed: part of it, for the large 
excretories, the vefica urinaria, inteflinum redtum, and in 
females the uterus, todifeharge themfelves. 
The thorax, or chef, reaches from below the neck to the 
belly ; and, by means of the bones that guard it, is form* 
ed into a large cavity. The figure of it is fomewhat co- 
noldal: but its upper fmaller end is not finiflied, being left 
open for the paflage of the wind-pipe, gullet, and large 
blood-veflels; and its lower part or bafe, has no bones s 
and is fliorter before than behind. The bones which form 
the thorax are the twelve dorful vertebra; behind, already 
deferibed ; the ribs on the fides, and the fiernum before. 
The ribs, or cofee, (as if they were atf odes, or guards, to 
thofe principal organs of the animal machine, the heart 
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