The interior journal. [volume] (Stanford, Ky.) 1872-1881, 1872-07-05

/ tive iOrcc OF muscular CONTRACTION ny "
terpcsing . spring, aud all the powers
which charedcmandcd TO overcome the effect
of that spring, is expended wastciully,
80 far as the actual propulsion Of The ami
NAL is concerned. Therefore Il Is that
Nature, in order togive greater efficiency
to the muscles of this portion Of the body.
has attached the hind cxtrcmitics 10 tho
frame by direct bony articulation, which
Is not the case with the front limbs
The function of the thorncic extremi-
ties, rs has already been stated, is 10 sup
port and direct, while that Of The hinder
limbs is to propel the frame. The sim
pie facts explain, in a few words, the
principles which should direct US in iudg-
ing Of the capabilities of the arimal nss
chine. With regard to the comparative
length of the upper and lower parts of
the extremity, it will be found that as
the length above the hook Is increased,
that below it is diminished. This is the
case, also, in the fore limb above ard be-
low the knee. If we have short quarter
or shoulders, il follows that the oolumn
Of support must he elongated some where.
which is then done below the hook and
knee. But if the animal is formed with
deep lorehand and long quarters, the
cannon bones are proportionately dimin-
ished in longitude. This is one reason
Of the advantage usually observed to fol-
low the possession of short cannon so
generally and properly esteemed
THE HAUScII, THIGH AND sTnLE.
The haunch is composed of three ir.
regular bones on each side, which, co.
alescing, form an arch for the support Of
the posterior part Of the body and the
protection of the pelvic vkcera. These
three bones become partially consolidated
into one, and form at their point of union
a cup for the reception of the upper or
true thigh bone, dcnominated BY horse
men the whirl or round bone. Their
union forms a ball and socket Joint,
which is covered with large masscs Of
muscle, thereby rendering it imperoep,i-
bic to outward view. The prominence
of the launches bones give advantageous
insertion to some Of the most poEerful
muscles Of the body, whose Office Is to as
sist in the propulsion Of the frame. From
aas.e hin -igiilt -thaL feiq,ir sQr. ihiah bono,
proper, slants forward 70 meet thcSns--<
Of the lower bone Of the thigh, (the leg
proper which, together with the patella
"a bone corresponding to our kncepan
constitute the stifie joint Attached
to the head Of the leg bone is short
bone called the iibula. The bones Of the
lower thigh are directed backward, form
ing a considerable angle with the iemur,
thus giving to the muscles acting on the
part of the mechanical advantage which
they would not otherwise possess f; st the
same time the weight is thrown on them
so obliqucly as to prevent conclusion.
The femur and tibia should be long, for
reasons we have alleged when treating on
the hind-quarter. 1t gives them a double
mechanical power; first by lengthening
the muscular fihor itself, and secondly,
by increasing the leverage at which those
muscles act.
THE nocK JOINT
Is part Of great importance. 1t Is com
posed Of no less than ten bones, between
some Of which extensive motnn exists,
while between Others the action Is incon-
siderable, but ON them the stress of cx-
ertion falls during progression. The
chief motion Of the joint is between the
lower head Of tho tib;a and the astrsga-
lus (very similar to our ankle joinD.
The oscalcis forms an important feature
on this joint; it projects bodily upwar'lJ
from the other. bones and gives attach
ment, more or less sdyaDtageous, accotd-
ing to It's length and direction, to the
tendons Of the most powerful muscles
flexing the limb. The pressure reflected
by this bone to those Immediately be-
meath it during the active oxcrtimH of
the animal must be enormous When
that is properly considered ii ceases to
be surprising that these parts are so ia-
bic to the disease called spawn, and the
only wonder is that they 80 long with
stand such extraordinary and severe ox-
ertion. The mechanical construction Of
the legs, fetlocks and pasterns is very
similar to the corresponding one Of the
fore extremitics, and needs no farther
descrition. ~ y. Hr0h.