forming the upper part of the back, whence they are termed
'dorsal'; five lie in the loins, bearing no distinct, or free, ribs, and
are called 'lumbar'; five, united together into a great bone, excavated
in front, solidly wedged in between the hip bones, to form the back of
the pelvis, and known by the name of the 'sacrum', succeed these; and
finally, three or four little more or less movable bones, so small as to
be insignificant, constitute the 'coccyx' or rudimentary tail.

In the Gorilla, the vertebral column is similarly divided into cervical,
dorsal, lumbar, sacral, and coccygeal vertebrae, and the total number
of cervical and dorsal vertebrae, taken together, is the same as in
Man; but the development of a pair of ribs to the first lumbar vertebra,
which is an exceptional occurrence in Man, is the rule in the Gorilla;
and hence, as lumbar are distinguished from dorsal vertebrae only by the
presence or absence of free ribs, the seventeen "dorso-lumbar" vertebrae
of the Gorilla are divided into thirteen dorsal and four lumbar, while
in Man they are twelve dorsal and five lumbar.

[Illustration: FIG. 15.--Front and side views of the bony pelvis of Man,
the Gorilla and Gibbon: reduced from drawings made from nature, of the
same absolute length, by Mr. Waterhouse Hawkins.]

Not only, however, does Man occasionally possess thirteen pair of
ribs, but the Gorilla sometimes has fourteen pairs, while an Orang-Utan
skeleton in the Museum of the Royal College of Surgeons has twelve
dorsal and five lumbar vertebrae, as in Man. Cuvier notes the same
number in a 'Hylobates'. On the other hand, among the lower Apes, many
possess twelve dorsal and six or seven lumbar vertebrae; the
Douroucouli has fourteen dorsal and eight lumbar, and a Lemur ('Stenops
tardigradus') has fifteen dorsal and nine lumbar vertebrae.

The vertebral column of the Gorilla, as a whole, differs from that
of Man in the less marked character of its curves, especially in the
slighter convexity of the lumbar region. Nevertheless, the curves are
present, and are quite obvious in young skeletons of the Gorilla and
Chimpanzee which have been prepared without removal of the ligaments. In
young Orangs similarly preserved, on the other hand, the spinal column
is either straight, or even concave forwards, throughout the lumbar
region.

Whether we take these characters then, or such minor ones as those which
are derivable from the proportional length of the spines