Year: 1873

prolongation of human life, and contrib
utes to that not less important object its
emancipation from disease. Let us con-
slider for short time the general charac-
ter of man, or rather those distinctive
characteristics of man. that separate him
from the lower animals, which approach
nearest to him in general structure and
aspect.


The first we notice consists of those
contrivances by which man is particular
ly adapted to the erect attitude. On ex-
amining his Uranium, we find that the
condyles by which it is articulated with
the spinal column. are so placed, that a
perpendicular let fall from the centre of
gravity of the head, would fall nearly be-
tween the condyles so as to be within
men magnum" is not placed in the cen
tire of the base of the skull, but just be-
hind it, in order to compensate for the
greater specific gravity of the posterior
part of the head, which is entirely filed
with solid matter, while the front part
L
little over compensation, which gives a
slight preponderance to the front part of
head, so that it drops forwards and
downwards when all the muscles are re-
laxed. But the muscles which are at
tached to the back of the head are stron-
ger and more numerous than those in
front of the condyles, so that they are
evidently intended to counteract this
disposition, and we find accordingly that
we can keep the head up for the whole
day with SO slight and involuntary an
effort, that no fatigue is produced by it.
Moreover the surface of the condyles
have a horizontal direction when the
head is upright, and thus the weight of
the skull is laid vertically by them upon
the top of the vertabral column. If these
arrangements be compared with the po-
sition and direction Of the occipitaI con-
dyles in other mammalia, it will be found
that these are placed in the latter much
nearer the back part of the head, and
that their plane is more oblique. Thus
whilst the foramen magnum in man is
situated just behind the centre of the
base of the skull, in the chimpanzer and
Orung Outan it will be found to occupy
the middle of the posterior third; and
as we descend through the scale of mann
malta we observe that it gradually ap-
proaches the back of the skull, and at
last comes nearly into the line of its
longest diameter, as we see in the horse.


The obliquity of the condyles differs in
a similar degree. In all mammalia ex-
cept man their plane is oblique, so that
if the head were equally balanced upon
them, the force of gravity would tend to
carry it forwards and downwards In
man the angle which they make with the
horizontal is very small, in the Orang
Outan it is as much as 370, and in the
horse their plane is vertical making the
angle 900 If therefore the natural posi-
tion of man was horizontal, he would in
this respect be circumstanced like the
horse, for the plane of his condyles which
is nearly horizontal in the erect position,
would then be-vertical, and the head in
stead of being nearly balanced in the
erect position, would hang at the end of
the neck. SO that the whole weight would
have to be supported by some external
and constantly acting power. But for
this there is, neither in the skeleton nor
in the muscular system of man, any ade-
quate provision. In other mammalia the
head is maintained in such position by
a strong and thick ligament, which pass
es from the spines of the cervical and
dorsel vertebra to the most prominent
parts of the occiput, but of this there is
scarcely trace in man. In the horizon
tai position therefore he would have the
heaviest load, with the least power of
supporting it. The position of the face
Immediately beneath the brain, so that
its front is nearly in the same plane as
the forehead is peculiarly characteristic
of man; for the crania of the chimpanzer
and Orang, which approach nearest to
that of man, are entirely posteror to, and
not above the face. 1t should be remark
ed that in the young ape there is a much
greater resemblance to man in this res
pect than there is in the adult. For at
the period of the second dentition, the
muzzle of the ape undergoes great elon-
cation, SO that it projects much more be-
yond the forehead. This increased pro-
lection of the muzzle is an evidence of
want of perfect adaptation to the erect |
attitude, whilst the absence of it in man,
shows that no other position is natural
to him. Supposing that, with head
formed as al present, he (man) were to
move on all fours, so that his face would |
be brought into a parallel with the |
ground, as painful an effort wolsld be re-
quired to examine with the eyes, an -oh-
ject placed in front Of the body, as is now |
necessary to keep the eyes fixed on the |
zenith The nose would be unable to per-
ceivo any other odors than those which, |
proceeded from the earth or from the
body itself; and the mouth could not
touch tho ground without bringing the
forehead, and chin also, into contact
with it.


You might improve the lower animals
in intellect, such improvement cannot by
any possible chance add to or subtract
from the skeleton o bone of such import
ance as vertebrn. The processes for
the attachment of muscles of the back,
to this part, are peculiarly large and
strong in man; and this arrangement is
obviously adapted to overcome the ten