e form, relative
position, and connection, of the bones constituting the human framework,
the engraving on page 70, (Fig. 1,) is given.

[Illustration: Fig. 1.]

By the preceding engraving, it will be seen, that the _cranium_, or
_skull_, consists of several distinct pieces, which are united by
sutures, (or seams,) as represented by the zigzag lines; _a_, being the
_frontal bone_; _b_, the _parietal bone_; _c_, the _temporal bone_; and
_d_, the place of the _occipital bone_, which forms the back part of the
head, and therefore is not seen in the engraving. The _nasal bones_, or
bones of the nose, are shown at _e_; _f_, is the _cheek bone_; _g_, the
_upper_, and _h_, the _lower, jaw bones_; _i_, _i_, the _spinal column_,
or back bone, consisting of numerous small bones, called _vertebrae_;
_j_, _j_, the seven _true ribs_, which are fastened to the spine,
behind, and by the _cartilages_, _k_, _k_, to the _sternum_, or _breast
bone_, _l_, in front; _m_, _m_, are the first three _false ribs_, which
are so called, because they are not united directly to the breast bone,
but by cartilages to the seventh true rib; _n_, _n_, are the lower two
_false_, which are also called _floating, ribs_, because they are not
connected with the breast bone, nor the other ribs, in front; _o_, _o_,
_p_, _q_, are the bones of the _pelvis_, which is the foundation on
which the spine rests; _r_, _r_, are the _collar bones_; _s_, _s_, the
_shoulder blades_; _t_, _t_, the bones of the _upper arm_; _u_, _u_, the
_elbow joints_, where the bones of the upper arm and fore arm are united
in such a way that they can move like a hinge; _v_ _w_, _v_ _w_, are the
bones of the _fore arm_; _x_, _x_, those of the _wrists_; _y_, _y_,
those of the _fingers_; _z_, _z_, are the round heads of the thigh
bones, where they are inserted into the sockets of the bones of the
pelvis, giving motion in every direction, and forming the _hip joint_; a
b, a b, are the _thigh bones_; c, c, the _knee joints_; d e, d e, the
_leg bones_; f, f, the _ankle joints_; g, g, the _bones of the foot_.

The bones are composed of two substances,--one animal, and the other
mineral. The animal part is a very fine network, called the _cellular
membrane_. In this, are deposited the harder mineral substances, which
are composed principally of carbonate and phosphate of lime. In very
early life, the bones consist chiefly of the animal part, and are then
soft and pliant. As the child advances in