GAS 
margin of the bone, half w ay down the eae In the reft of 
its extent it is unattached. ‘The external mar gm 3 is uncon- 
nected throughout, and offers not hing worth 
The upper extremity of the rautcle is i 
fixed to the upper“and back p 
point it defce i along the a of the leg, _ growing broader 
o ths middle of the Fimb, and then contracting again to the 
infe erior extreni whica is fixed to the lower and back part 
of the os ca 
The fracture of the feleus is te ite: aponeurotic, = 
fiefhy. Tts attachment to the 03 calcis is by means of a v 
ae erful age camee tendo Achilis, ‘which is fixed a 
e poiterior furface of the bone. 
é tendon is in contaét with the upper 
half of the back fre of the bone, which is covered by a 
ayer of cartilage. A thin fynovial membrane expanded 
fed furfaces renders them {mooth, and confines 
ever the a 
oe Raha nae are lubricated. As the tendon 
alcis, 
a 
ee as we have already defcribed, to the 
mus, a much more ae eae one to the foleus. 
grows broader as it a 
ee whole potterior oe of the mufcle, excepting the up- 
per extremity. 
From its anterior furface, near the outer margin, there 
arifes an aponeurotic feptum, which afcends among the 
approaches gradually to the middle of the 
Two other pa neurofes, an internal and an exter- 
nal one, may be obferved towards the upper part of t 
front of the foleus. The firft arifes from the oblique line at 
the back of the tibia, and from its inner edge, and defcends 
S 
rm 
ma 
oO 
on the inner fide of the front of the mufcle below its middle. . 
The iatter proceeds from the upper extremity and outer mar- 
gin of the fibula, and defcends | 
mufele? i i 
on the op poke f fae with de internal ern From the 
two aponeurofes juft defcribed the mufcular fibres arife, and 
anterior furface of that which covers 
mle, and to the fides of ai ola ine 
eptum, which oil in the fubftance of the m 
defcend along the cern furface of the tendo Ackil, - 
within three cues of its attachment to th calci 
Afton of thefe Mufcles—The mufcles of the ar are par- 
fic wee employed i in progreffion 5 ; and their bulk and power, 
with thofe of the gluteal muicles,. prove that the human fub- 
ject was defigned to walk er ss Fence man is ae soroat 
characterized by the largenefs of calf, and no anim 
es him in this refpect. the attitude of ftan ding, w ne 
2 foot refts firmly on the ground - a having its fixe 
on in the heel, keeps the leg backwards, and prevents it 
from obeying the sectleney: which ni weight of ie body 
gives it, to bend forwards on the foot. When the leg has 
been carried forward on the foot, the latter part being Axed 
to the ground, this mufcle will reitore it to its ere pofition, 
by moving it ba ee on the foot. he ea 
fixes the thigh roa e foleus does the leg ; and op- 
s the crura 
saa vafti which hold the bones in fore. 
ie their ation | is carried beyond the degree now defcrib- 
the gaftrocnemius may ee the thigh backwards, or 
foleus the leg. 
y lifting the heels, when the body is ereét, the mufcles 
of the calves elevate 10le body, which is giapies on 
the two aftragali: the ee is there maintained. by the an- 
GAS 
terior = of the feet, and the individial is faid to ftand on 
tiptoes. If the foot of one fide be 1i5 2d from the ground, 
and ve oppofite heel be raifed by the calf of its own ude, 
the whole bedy is then elevated by the mufcles of ene calf, 
en a perfon ftands on tiptce with a burden on the fhould 
ers, or any other part of the trunk, the weight of this, as 
well as of. the body, muft be Ree and fupported by the 
muifcles of the calf. 
n progrefiion, the ae and gaftr ral wi hfting the 
heel, make the foot cribe fae circle, oint relling 
on the ground, and ae hel being ee This motion 
increafes the length of the lower extremity by the whole 
length of the foot, and gives an impulfe to the trunk 3 which 
propels it forwards. See the article Extremities for a 
SS account of the mechanifm of this motion. Running 
thefe mufcles in powerful action: the ron nt of the foot 
ae refts on the ground at each fiep, the back pertion being 
kept conftantly elevated. Their action is equally oblerved 
in leaping, al the inftant when the heel quits the ground. We 
may obferve here that thefe mufeles of the lane: limbs, 
which, by their fudden sa sale ftrengthen the previouily 
bent articulations, are by far t a a erful. ‘This niay 
be feenin the fo ie ies with ia arikle, j in as vaiti and 
cruralis, to the knee, an in the ee is Maximus, to the hip. 
The height to pre the hip is fometimes clevat a in leap- 
ing is altonifhing. The fact is explained byt e@ power of 
thefe mufcles, difpefed firtt behind, then in one and then 
behind again, to accord es the ae aes directions in which 
tej joints i are bent. - vait force exerted by the mufcles of 
e calf, in raifing the a fie in jumping or dancing, a ccounts 
alfo for the rupture of the tendo Ac hills. The unfayour. ied 
manner in which the mufcles a in elevating the bedy, when 
we afcend an eminence, explains the weight and f atigue expe- 
rienced at thofe times in the calf of the leg. T he gaftroc- 
nemius may affift the flexors of the knee in bending the lez or 
the thigh. 
he pla ies ee its diminutive ae ean have but lit tle 
fhare in the movements juft defcribed : auft produce juit 
the ie effect as che e gaftrocnemius. Asit’ is frequently ab- 
fent, its office cannot be very important 
GASTROCOLICA Vena, (from yarns the fomach, 
and xsA0o:, the colon,) a > which pours its blood into the 
vena portarum. See 
GASTRO COLICUM oem is the fame as the 
great omentum. See Epi 
GASTRODIA, in en ee onony having a fwelling, 
or ventricofe, form; in allufion to the fhape of the flower, 
which in this family i is fingular.)—Brewn Prod. Nov. Holl. 
v1. 330.—Clafs and order, Gynandrta Monandria. Nat. 
Ord. Orchidee. 
2 
en. Ch. Cal. Perianth fa iia coloured, of one leaf, 
tubular ; the oA ce in hort, eae rather nae 
obes, all dire poets on e. Petalg none. 
Neary enclofed 1 in ee ek ae on ce organs cf im- 
pre ae n, fupport claw, uncenne eéted. Stam. 
Anther terminal, ces ee its cells clofe tege- 
ther; mafles of pollen of large angular particles, cohering 
elaftically. Pit. Germen inferior, pear-fhaped, nearly clo. 
a ribbed ; ftyle columnar, elongated, but fhorter than 
allan exca pare at : t Ps ore at the aie in 
the 
fule oats ean ar. Seeds num 
Eff. Ch. Caly x of one leaf, ae five-cleft, 
ee unconneéted. Anther vertical, 
. G. fefamoides. Native of Port Jackfon, where, ac- 
cae to Mr. R. Brown, it is very rare, he oe never 
feen more e than fix or feven fpecimens. We ived one 
from 
Lip 
