170 ANATOMY OF THE RABBIT. 
extremity by a constricted area or neck (collum femoris), so that, 
unlike the case of the anterior limb, the points of muscle attach- 
ment fall a considerable distance from the point of articulation. 
The actual extremity of the bone is formed by a large procéss for 
muscular attachment, the great trochanter (trochanter major). 
It is divided into two portions, one of which, the first trochanter 
(trochanter primus), forms the large terminal, hook-like projection, 
while the other, the third trochanter (trochanter tertius), is 
the smaller lateral crest. On the medial side of the bone, imme- 
diately distal to the head, there is a triangular elevation, the 
lesser, or second trochanter (trochanter minor s. secundus). 
Posteriorly, these projections form a smooth surface for muscle 
attachment, except, however, at the base of the trochanter major, 
where the surface of the bone presents a deep, though narrow, 
depression, the trochanteric fossa (fossa trochanterica). 
The distal extremity bears an extensive surface for articulation 
with the tibia. It is divided into two portions, known as the 
medial and lateral condyles, through the presence of a deep 
excavation, the intercondyloid fossa (fossa intercondyloidea). 
Immediately above the condyles, on the anterior surface of the bone, 
the intercondyloid fossa is replaced by a broad groove, the patellar 
surface (facies patellaris), which, in the natural condition, accom- 
modates the convex internal surface of the patella. The medial 
and lateral portions of the bone, intervening between the distal 
portion of the patellar surface and the tips of the condyles, provide 
slightly elevated, roughened surfaces, the medial and lateral 
epicondyles, for muscular attachment. 
THE TIBIA AND FIBULA. 
The tibia (Fig. 71) is the larger of the two bones of the leg, lying 
on the medial side of the fibula, and fused with the latter for more 
than one-half of its length. Its proximal extremity is triangular 
in section, the main surfaces being respectively anterolateral, 
anteromedial, and posterior. The anterior border is formed by a 
stout ridge-like elevation, the tuberosity of the tibia (tuberositas 
tibiae), which in the natural condition serves for the insertion of © 
the quadriceps femoris, the extensor tendon being carried over 
