PRIMROSE : THE ANATOMY OF THE ORANG OUTANG 
45 
primus volaris of Henle, and Cunningham confirms him in every par- 
ticular. In the case of the foot Flemming advanced an argument based 
upon the nerve supply, but his argument fails, because Cunningham has 
shown that Flemming followed Henle and Schwalbe in describing the 
nerve supply of the fibular head to be from the external plantar nerve, 
whilst throughout the entire class of the mammalia Cunningham has 
only once found this head thus supplied in the fox-bat), with this ex- 
ception it is always supplied by the internal plantar, as is the tibial head. 
Even if Flemming were right regarding the nerve supply Cunningham 
holds that the point would not afford sufficient proof, as it has been shown 
that where two nerves approach one another, a tendency to variation in the 
supply to muscles occurs when they reach the confines of their distribution. 
Cunningham states that in only one instance was he able to trace the 
nerve supply of the interosseus primus volaris in the hand, and in that 
instance it appeared to come from the deep branch of the ulnar. 
The Abductor minimi digiti (plate V, fig. 5 abjn.d.\ arose from the 
pisiform bone and the annular ligament, and was inserted into the base 
of the first phalanx of the little finger on its ulnar side. 
The Flexor brevis minimi digiti (plate V, fig. 5 fl.b.m.di) arose from the 
unciform bone and the annular ligament, and was inserted into the base 
of the first phalanx of the fifth digit on its ulnar side. In Tick’s Orang 
a second head arose from the palmaris longus tendon. 
The Opponens minimi digiti (plate V, fig. 5 op.m.di) arose from the 
unciform bone and the annular ligament, and was inserted into the 
whole length of the metacarpal bone of the little finger. 
The short muscles of the thenar and hypothenar eminences have a 
greater or less extension of their fibres of insertion beyond the bony 
points already described, and blend with the extensor aponeurosis on the 
dorsal aspect of the digits. In this respect they resemble the interossei, 
and Langer would, from this circumstance, argue in favour of the 
theory that these muscles are modified interossei. 
The Orang would appear to have a greater development of thumb 
muscles than obtains yn the hand of man as far as the development of 
those muscles which act upon the metacarpal bone is concerned, but the 
movements of the terrhinal phalanx are obviously very weak, the flexor 
longus pollicis being absent or extremely rudimentary. Further, it 
would appear that adduction to the index is the most powerful move- 
ment attainable, as judged from the development of the muscles. The 
I Loc. cit., p. 184. 
