With respect to the orbits, the writer follows his invariable custom
of making measurements on both sides and recording the mean, which, in
turn, gives rise to a mean index. This procedure is necessary in view
of the fact that in only a minority of cases are the two orbits of
equal dimensions and that sometimes they differ considerably.[27]
Among the series of Lenape crania which the writer reported on in
1902,[28] there were several specimens in which the orbits were
unusually low. At that time it seemed as if this feature might be
almost characteristic of these Indians; but evidently such is not the
case, for low orbits are quite rare among the Munsee. As will be seen
from the following figures, in only one instance (male, no. 285,313)
are the orbits decidedly low and broad, giving the microseme[29] index
of _78.1_. Of the remaining cases four males and two females (43 per
cent) are mesoseme, while two of the males and five of the females (50
per cent) are megaseme. The extensive fluctuation of the orbital index
in both sexes of the Munsee tribe is very striking, but much the same
variation was observed in the Arkansas and Louisiana crania previously
mentioned, and is present among the Eastern tribes in general.
[27] It seems advisable to mention at this point the exact method used
by the writer in the measurement of the orbits, for there appears to
be not a little discrepancy in this respect among different workers.
The measurements are those of Broca: The breadth is from dacryon (the
point of intersection of the lachrymo-frontal suture and the sharp free
orbital border of the lachrymal canal) to the most distal part of the
lateral boundary of the orbit, below the malo-frontal suture; while the
height is the maximum height, from about the center of the lower border
of the orbit. Both dimensions can be taken with fair accuracy by either
a graduated rod or by the two sharp points of the _compas glissière_.
The main point is that the measurements should not comprise any part of
the borders of the orbits, particularly the outer one, which differs
considerably in thickness and breadth, and part of which seems not
infrequently to be included by those who take these measurements.
[28] _Crania of Trenton_, etc., op. cit.
[29] Broca’s classification.