276 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
The flexors exhibit a very interesting condition ; in all cases the deep 
flexor, or perforans (Fig. P, fla. perf.’), sends a small tendon to the 
extra digit ; this apparently is not formed by the division of the tendon 
which supplies digit 1, but is given off from the main tendon independ- 
ently and more proximally. It may represent the radial portion of the 
flexor perforans. In the three cases where the second digit is abnormally 
o--]-------f------- flz. perf.’ 
IV. III. 
Fic. P. — Posterior view of left polydactyle manus, showing flexor muscles. lz. perf, 
flexor perforatus; flx. perf’., flexor perforans. 4% natural size. 
large, the tendon of the perforans supplying this digit is much stronger 
than usual. The superficial flexor, or perforatus, is normal in most cases, 
but in one instance has three insertions, an extra tendon going to the 
second digit. 
The innervation of these cases is identical with that shown in Fig. Z, 
