18S1.] 



OF CERCOPITHECUS CALLITRICHUS. 



815 



side of the tendon of ihejlexo?' proftmdus for the pollex, and is in- 

 serted into the base of the terminal phalanx of that digit. The ab- 

 ductor, adducfo);and opponens pollicis are well developed ; i\\& flexor 

 pollicis brevis smaller, and quite concealed by the abductor pollicis. 

 These last four muscles are quite distinct from the small muscle above 

 described, which arises much higher up, and the tendon of which passes 

 forwards superficial to all. It is difficult to trace the homology of 

 this muscle, which corresponds in its insertion to that of the flexor 

 pollicis longus of human anatomy, but differs altogether in its origin. 

 Is it a separated part of the abductor pollicis or of the flexor pollicis 

 brevis 1 



The abductor minimi digiti is very large, arising by two heads, 

 one from the pisiform bone, the other from the annular ligament 

 in common with t\\^ flexor minimi digiti ; both unite to form a round 

 tendon, which has the usual insertion. Flexor minimi digiti is also 

 well developed, and larger than i\\e flexor ossis metacarpi minimi 

 digiti. The four lumbricales are well developed ; they arise together 

 from the palmar surface of the yet united four inner tendons of the 

 flexor digitorum profundus. 



fi.lan^.diff. 



^.lonff.hull 



Cercopithecus ea Uiirichus. 



Flexor muscles of right foot, ad. (J. 



ft. hr. Flexor digitorum brevis ; ft. ace. flexor accessorius ; I, I, I. lumbricales ; 

 fl. long. dig. flexor longus digitorum (distr. to second and fifth toes) ; 

 fl. long. hall, flexor longus hallucis (distr. to first, third, and fourth toes) ; 

 pi. tendon of plantaris. 



In the foot \ki& flexor digitorum brevis tendon for the second digit 

 arises from a bundle of muscular fibres having their origin wholly 

 from the expanded plantaris tendon ; lower down it is joined by a 

 few muscular fibres arising irom the tendon of the flexor digitorum 

 longus (fig. 1.), the other _;?e.vor brevis tendons having their origin 

 from muscular fibres arising from the conjoined tendons of the j^e.ror 

 digitorum longus and_/?e.ror hallucis longus. Tiie three hanbricales 

 are well developed and have the same mode of origin in both feet, 

 arising from the inner sides of the flexor tendons for the three outer 

 toes, into which they are inserted. The transversus pedis is present, 

 but instead of arising, as in the human foot, from the extremity 

 of the fifth metatarsal bone, arises from that of the second and by a 

 fascial aponeurosis from the shaft of the third (fig. 2). 



