ometer, measurements may be taken with
calipers, the arms of which are curved like the ordinary pelvimeters
used in obstetrics (see Fig. 31), and a graduated steel tape.

The following are the principal measurements:

1. Maximum antero-posterior diameter, which is obtained by applying one
arm of the instrument above the root of the nose just between the
eyebrows and sliding the other arm over the vault of the skull till it
reaches the occiput. The distance between the two arms furnishes the
maximum longitudinal diameter.

2. The maximum transverse diameter or breadth of the skull is measured
by placing the arms of the calipers, one on each side of the head on the
most prominent spot.

3. The antero-posterior curve is obtained by fixing the graduated tape
at zero on the root of the nose (on the fronto-nasal suture) and passing
it over the middle of the forehead, vertex, and occiput to the external
occipital protuberance.

4. The transverse, or biauricular curve is obtained by applying the
steel tape at zero to a point just above the ear, and carrying it over
the head in a vertical direction till it reaches the corresponding point
on the other side.

5. The maximum circumference is obtained by encircling the head with the
steel tape, touching the forehead immediately above the eyebrows, the
occiput at the most prominent point, and the sides of the head more or
less at the level, where the external ear joins the head, according to
whether the position of the occipital protuberance is more or less
elevated. (See Figs. 32, 33.)

6. The cranial capacity is obtained by adding together these five
measurements, the antero-posterior diameter, maximum transverse
diameter, antero-posterior curve, transverse curve, and maximum
circumference. For a normal male the capacity is generally 92 inches
(1500 c.c).

=FIG. 32 FIG. 33
Diagram of Skull=

7. The cephalic index is obtained by multiplying the maximum width by
100 and dividing the product by the maximum length, according to the
following formula:

W x 100
------- = X (cephalic index).
L

If the longitudinal diameter is 200 and the transverse diameter 100, the
cephalic index is 10,000 divided by 200 = 50.

The cephalic indices of degenerates, like their height, have only a
relative importance; that is, when they are compared with the mean
cephalic index prevalent in the regions of which the subject is a
native. The cephalic index of Italia