The entire number of vertebræ of 21 skeletons has been preserved, thus
affording an excellent opportunity for studying the numerical relations
of the bones, as well as other particulars.
The bones are entirely normal, with the exception of the frequent
slightly to moderately developed marginal exostoses (which, unless
premature or excessive, the author regards more and more as the usual
manifestations of age rather than of disease), and one case of advanced
spondylitis deformans, resulting in fusion of the lower half of the
spine and the sacrum. The bones show moderate to medium development and
are free from gross anomalies.
As to numbers, the cervical vertebræ show but one exception to the
normal—namely, in male skeleton no. 285,326, in which only six vertebræ
are present in this region. The locus of the (congenitally) missing one
is between the third and the sixth, its exact identity being difficult
to determine. In one of the females (no. 285,311) the seventh cervical,
as already mentioned, gives attachment on the right to a well developed
cervical rib (pl. 25, _a_).
The vertebræ of the dorsal region are also normal in number in all
cases but one, which has been mentioned in connection with the ribs;
it is no. 285,321, female, and presents a congenital absence of the
twelfth vertebra.
The numbers of the lumbar vertebræ show frequent variation. In two of
the ten males and two of the eleven females there are but four lumbars,
while in one female there are six. In detail we find the following
abnormalities:
In male skeleton no. 285,316, the fifth lumbar shows a transitional,
sacral form, though not attached to the sacrum, and it also presents a
detachment of the posterior part of its neural arch.
In male no. 285,326, one of the lumbar vertebræ between the second and
fifth is absent congenitally.
In female no. 285,310, one of the lumbar vertebræ is missing
congenitally; the last lumbar in this case is in form like the fifth;
the upper segment of the sacrum is somewhat lumbar-like, but the bone
possesses only five segments and a normal curvature.
In female no. 285,311, with four lumbar vertebræ, the fifth, somewhat
modified, is attached to the sacrum (pl. 27).
In female no. 285,326, where we have six lumbar vertebræ, the last,
like the lowest lumbar in male no. 285,316, shows a separation of the
posterior portion of the neural arch.
In male no. 285,308, the twelfth dorsal and the first lumbar show
complete and evidently early non-pathological fusion.
[Illustration: BUREAU OF AMERICAN ETHNOLOGY BULLETIN 62 PLATE 26
_a_ MALE MUNSEE SACRUM SHOWING BILATERAL ARTICULATION WITH AN EXTRA
SEGMENT INTRODUCED BETWEEN THE LAST LUMBAR AND THE SACRUM]
[Illustration: _b_ FEMALE MUNSEE SACRUM SHOWING BILATERAL ARTICULATION
WITH EXTRA SEGMENT]