456 BE. C. MacDowell. 
from the interosseous membrane, and from the intermuscular 
septum between it and the peroneus longus. The tendon is 
large and stronger than that of the preceding muscle. It is 
free from muscle fibers before reaching the plantar surface. Here 
it divides in half. One branch, passing under a ligamentous 
band on the inner palmar aspect of the base of the first metatarsal 
bone, is inserted into the terminal phalanx of the first digit. The 
other branch divides, sending perforating tendons to the third and 
fourth digits. The baboon presents the same arrangement 
(fig. 5, H), excepting in the tendon to the first digit, which arises 
as much from the flexor digitorum longus as from the hallucis. 
Thus, the two tendons are firmly united at this point, allowing 
far less independence in the flection of the terminal phalanges of 
the thirdand fourth digits. Michaélis describes a similar arrange- 
ment in his chimpanzee and in his baboon. Owen, Hartmann, 
and Primrose describe no tendons to the hallux in their orangs. 
Duvernoy found the same lack in a chimpanzee. Dobson says 
that this muscle supplies the three middle digits in the Simiade. 
The main variations that have been described refer to the 
relation of the tendon to the first digit, the insertion into third 
and fourth digits being constant. (See table IV.) 
The Flexor digitorum brevis will be described as the muscle whose 
bellies supply the perforated tendons to the digits. In the chim- 
panzee (fig. 4, B), it arises from the calcaneum in close relation 
to the abductor hallucis brevis and from the tendon of the flexor 
digitorum longus. The tendon of the second digié arises from the 
main belly from the calcaneus. The tendon from the third digit 
arises from a belly that also takes its origin from the “longus” 
tendon. A few of the fibers from this insertion extend so far 
back along the tendon that they become continuous wich those 
from the belly of the ‘“‘longus” that have crept far down the ten- 
don. However, as most of the fibers arise from the tendon just 
as it divides, it seems fair to have called this belly a separate mus- 
cle and not to have described its tendon as one from the flexor 
digitorum longus. The perforatus tendon for the fifth digit is 
lacking. Hartmann considers the division arising from the ten- 
don of the flexor digitorum longus as a part of that muscle. He 
