674 
Recently, improved methods have shown that 
these ratios have as wide range of variability as 
the measurements themselves and it has been found 
necessary to apply rigid statistical methods to the 
actual dimensions, The most constant characters 
of a large number of individuals must be observed 
and selected for measurement. In the past the 
head measurements have been considered of most 
importance and most constant. For the Harvard 
Expedition to South America De Milhau devised a 
cephalometer which allowed one to take measure- 
ments from the center of the auricular passage to 
any desired position on the head or face. For 
comparative group studies these dimensions were 
most satisfactory. Yet one very important factor 
was lacking, viz., the angle between the lines, 
which prevented any possibility of graphic pre- 
sentation. To overcome this defect and to min- 
imize as far as possible the importance of defi- 
nitely locating all the positions mentioned, a 
protractor was attached to record these angles. 
This made it possible to locate the points to which 
the measurements were made, whether or not the 
positions were correctly determined. All measure- 
ments and angles were taken with reference to 
the horizontal plane of the Frankfort agreement. 
The vertical height is perpendicular to this plane 
and this line is marked zero in the scale. 
When all results have been worked out according 
to correct statistical methods it will be possible to 
plot the means of all angles and measurements 
and when the ends of these lines have been con- 
nected by means of a spline a type contour will 
result. In the same way type contours of dif- 
ferent related or unrelated groups in races may 
be made. These contours should be plotted on 
thin paper and superposed for comparative study. 
The advantage of the method is that it may be 
applied to the cranium as well as, to the living 
head and direct comparisons made to determine 
relationships. Head measurements may be re- 
duced to cranium measurements by allowing for 
the thickness of the cranial tissues. 
Some Factors in the Differentiation of Human 
Types: ROBERT BENNETT BEAN. 
Dr. Bean has studied random samples from four 
groups of mankind, Europeans, Africans, Hast 
Indians and Filipinos, and in each group three 
types that are similar in physical characteristics 
may be segregated. He has heretofore called these 
three types Primitive, Australoid and Iberian, but 
here they will be designated A, B and C, re- 
spectively. 
SCIENCE 
[N.S. Vou. XXXV. No. 904 
Type A is small, brachycephalic and platyrrhine. 
Type C is tall, dolichocephalic and leptorrhine. 
Type B is medium in stature, mesocephalic or 
mesaticephalic and platyrrhine. 
From the standpoint of growth other factors 
may be utilized to differentiate the types. It is 
known that the relative total leg and arm length 
increase from birth to maturity, the face increases 
in size, and the umbilicus descends. To make 
these factors relative we may use the length of 
the leg in relation to stature, the length of the 
arm in relation to stature, the size of the face in 
relation to the size of the head and the position of 
the umbilicus in relation to the position of the 
suprasternal notch and the symphysis pubis. 
Dividing the length plus breadth of the face by the 
length plus breadth of the head gives a ecranio- 
facial index, which is low at birth and high at 
maturity. Dividing the distance of the umbilicus 
from the symphysis pubis by the distance of the 
umbilicus from the suprasternal notch gives the 
omphalic index, which is high at birth and low at 
maturity. 
The three types may be assembled by the use of 
these factors according to the stage of develop- 
ment that each represents, as follows: 
Type 4 
Hypo-onto-morph 
Type C Type B 
Meso-onto-morph Hyper-onto-morph 
Relative total arm length 
Small intermediate large 
Relative total leg length 
Small intermediate large 
Cranio-facial index 
Small intermediate large 
Omphalie index 
Large small q 
Type A is less developed than type B, and type 
C is intermediate. 
Additional factors, mainly descriptive, have been 
utilized to differentiate the three types, the form 
of the external ear or pinna enabling one to 
classify any individual after close scrutiny. The 
distinctive differences of ear form refer particu- 
larly to the inversion or eversion of the outer rim 
of the concha, and the rolling in (forward) or roll- 
ing out (backward) of the helix. These changes 
are especially to be seen at the lower part of the 
ear in the region of the tragus’ and antitragus, 
and the helix and antihelix. The ear of type 4 
has an inverted concha—the tragus and anti- 
tragus appear to be pushed in—and an inrolled 
helix, giving it a trumpet or bell shape. The ear 
