Figure 8. Coronal sections of the posterior portion of an adult rabbit symphysis. In all
four views, the upper edge is the dorsal surface and the lower is the ventral aspect. In top
and bottom pairs, “I” denotes each incisor in the left panel, while the right panel is a
magnified view of each inferior region. Top: section stained with periodic acid-Schiff
reaction for complex mucopolysaccharides. The lack of darker levels of staining
suggests the lack of extensive cartilage matrix and calcified cartilage along the posterior
symphysis, while the darker posterior transverse ligaments along the inferior border
indicate increased levels of calcification/ossification, i.e., partial fusion, than noted for
the anteroposterior (AP) cruciate ligaments. AP cruciate ligaments (directed out of the
plane of this figure) are noted for a variety of mammals, limited in distribution along the
joint and check AP movements of the symphyseal plates relative to one another. Bottom:
section stained with Mallory’s trichrome to identify hard and connective tissues. Note
again the AP cruciate ligaments (at center) and the posterior transverse ligaments (lower)
attached to the symphyseal rugosities.