ANATOMICAL STRUCTURE OF ANTHROPOID APES. 177 



From the extensor brevis digitorum the belly for 

 the great toe rises with a certain independence. 

 On the right foot of a chimpanzee I observed a fifth 

 belly of this muscle, going to the little toe (Fig. 55). 



Fig. 54. — Muscular system of the human foot. 1, Tibialis anticus and extensor 

 proprius poUicis. 2, Extensor longus digitorum. 3, Tendon of peroneus ter- 

 tius. 4, 5, Peroneus longus and peroneus brevis. 4', 5', Tendons of the same. 

 6, 7, Tendons of the extensor longus and extensor brevis digitorum. 



As my illustration is taken from this specimen, 

 I have represented the foot with, or in spite of, this 

 interesting anomaly, which, as we know, sometimes 

 occurs in man. 



The flexor brevis digitorum displays perforated 



