REGIONAL ANATOMY 19 
by the superior carpal ligament, passes through the carpal 
and metacarpo-phalangeal sheaths, and, arriving behind 
Fic. 11.—THe Fiexor PERFORANS AND FLEXOR PERFORATUS 
TENDONS. 
The metacarpo-phalangeal sheath and the ring of the perforatus laid 
open posteriorly, anid the cut edges reflected to show the passage 
of the perforans. 
1, Reflected cut edges of the perforatus ring and the metacarpo-phalangeal 
sheath; 2, the perforans tendon; 3, point of insertion of the perforans 
tendon into the semilunar crest of the os pedis (this widened and 
thickened extremity of the perforans is known as the plantar aponeurosis). 
the fetlock, forms a ring for the passage of the flexor 
perforans. Its termination is bifid, and it is inserted on 
either side to the lateral surface of the second phalanx. 
2—2 
