PRIMROSE ; THE ANATOMY OF THE ORANG OUTANG 
43 
of the first and last digits. The abductor pollicis, and the abductor 
hallucis, arising from what he considers to be the rudiments of the 
praepollex or prsehallux, and the abductor minimi digiti in both hand and 
foot arising from the postminimus. These abductor muscles together with 
the so-called “ interossei/’ Bardeleben would designate the flexores 
breves profundi.’^ In addition, Bardeleben claims certain of the marginal 
long muscles as contributing to the praepollex, etc.; among others, the 
extensor ossis metacarpi pollicis, and flexor carpi radialis acting on the 
pr^pollex, and the flexor carpi ulnaris acting on the post minimus rudi- 
ment. He traces similarly corresponding muscles in the foot. Fick^ 
discovered in man what he believed to be a flexor praepollicis. It arose 
from the outer margin of the radius near the insertion of the pronator, 
and as a continuation of the flexor longus pollicis, a portion was inserted 
into the transverse carpal ligament, but the chief tendon of insertion 
was attached to the volar projections of the trapezium and the scaphoid, 
processes which were considered by Pfitzner to represent the praetra- 
pezium, and therefore the praepollex rudiment Fick places consider- 
able importance upon the fact that this praepollex rudiment was still a 
“ rudiment ” in the oldest known mammal, and concludes that it is 
highly improbable, therefore, that the primitive mammal possessed a 
true praepollex. This fact would also go to disprove the other theory 
that the praepollex, etc., are secondary new formations. These digits, if 
they exist, do not appear to have made any progress in development in 
the mammal. 
Gratiolet and Alix^ found the extensor ossis metacarpi pollicis in- 
serted in the Chimpanzee by two tendons — one into the trapezium and 
the other into the base of the first metacarpal. In a foot note these 
authors refer to the fact that no sesamoid bone was present in the slip 
to the trapezium, and its absence they attribute to the fact that the 
animal was young. The explanation is not valid, as the bone was 
present in my Orang, although it was a young specimen. 
The Abductor pollicis (plate V, ^ abpi) muscle was well developed; 
it arose from the trapezium and the annular ligament, and was inserted 
into the radial border of the proximal phalanx of the thumb. The 
muscle would appear to present very few variations in the ape from the 
condition found in man. In Hepburn’s Orang it arose from the annular 
ligament and had no direct attachment to the carpal bones. 
The Opponens pollicis arose from the trapezium and the annular 
1 Loc. cit. I. p. 27. 
2 Loc. cit., p. 163. 
