=Ox.=—There is a considerable communication between the femoro-patellar
and inner femoro-tibial joint cavities; this is situated as in the
horse, but is wider. A small communication with the external
femoro-tibial capsule sometimes occurs. The two femoro-tibial capsules
usually communicate. The middle patellar ligament is not sunken, as
there is no groove on the tuberosity of the tibia where it is attached.
The external patellar ligament fuses completely with the tendon of
insertion of the biceps femoris, and a synovial bursa is interposed
between them and the external condyle of the femur.
In the other animals there is a single ligamentum patellæ, and the
synovial sacs communicate so freely as to constitute a common joint
cavity. In the dog the semilunar cartilages are united anteriorly by a
transverse ligament, and the posterior part of the capsule contains the
two Vesalian sesamoids, which articulate with the condyles of the femur.