_a_, Wing; _b_, dorsal sacral foramina; _c_, articular process; _1–4_,
segments or sacral vertebræ. (Ellenberger-Baum, Anat. d. Haustiere.)
]
The =coccygeal vertebræ= are specially characterized by the presence of
functional articular processes on the first four or five, beyond which
these processes become non-articular and smaller. The arches of the
first five or six are complete. The transverse processes are broad and
plate-like in the anterior part of the series and diminish very
gradually.
The numerical variation here is twenty to twenty-six according to the
observation of several anatomists. Lesbre states that he has found
twenty-three most frequently.
=Curves.=—The cervical region is practically straight. The thoracic and
lumbar regions form a gentle curve, concave ventrally, the highest point
of which is at the junction of the two regions. The sacral promontory is
not so pronounced as in the ox, and the sacral curve is flatter.