128 The Alligator and Its Allies 
muscle. (b) Caput internum: this springs without 
a tendon from the whole posterior surface of the 
upper half of the tibia, sometimes, as in crocodiles, 
uniting with the caput femoralis of the gastro- 
cnemius muscle. The common tendon splits into 
three points for the first, second, and third toes. 
Tibialis Posticus (Plate V., Fig. 2, tib. post.) 
(Jambier postérieur, Hinterer Schienbeinmuskel). 
Originates without tendon from the whole fibular 
side of the tibia, on the one hand, and from the 
whole inner and forward side of the fibula on the 
other hand, occupying the whole space between 
these two bones on the hinder side of the lower 
leg. At its proximal end it is united with the 
caput internum of the preceding muscle which 
completely covers it from behind. It narrows 
down to a very strong tendon which divides into 
two equally strong, round tendons; of these the 
one on the tibial side is inserted on the basis ossis 
of the first metacarpal, the one towards the fibula 
goes immediately to the second metacarpal. 
Interosseus Cruris (Kniekehlmuskel). A small 
muscle stretching between the distal ends of the 
fibula and tibia with almost transverse fibers; it 
is covered dorsally by the tibio-fibulare ligament 
and appears as a distal division of the tibialis 
posticus muscle. 
Flexor Digitorum Brevis (Flexor longus acces- 
sorius, Flexor brevis perforatus). Springs from the 
bones of the foot and from the strong tendon of the 
