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bulletin: museum of comparative zoology. 



The flexors exhibit a very interesting condition ; in all cases the deep 

 flexor, or perforans (Fig. P, fix. perf.'), sends a small tendon lo the 

 extra digit ; this apparently is not formed by the division of the tendon 

 ■which supplies digit ii, 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 



Fig. p. — Posterior view of left polydactyle manus, showing flexor muscles, fix. pcrf., 

 flexor perforatus; Jlx.perf., flexor perforans. I 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. L. 



