PRIMROSE : THE ANATOMY OF THE ORANG OUTANG 
13 
The function served by the laryngeal sac, as I have said, is a problem 
not yet solved. Fick observed a slight bellowing of the sac in the Orang 
when the animal was howling, and he also noticed a slight blowing up 
of the sac in the second or expiratory act of yawning. In coughing, on 
the other hand, no effect was noticed upon the sac. Sandifort long ago 
suggested that the sac permitted the storing up of air which was brought 
into use in prolonging the loud roar of the animal, but, as Huxley 
pointed out, the position of the sac above and not below the vocal cords 
is inconsistent with this theory. 
The great length of the arms in the Orang is a striking feature in 
comparing the animal with man. The lower extremities in man exceed 
the upper in length ; the reverse is true of the Orang. The measurements 
in my orang were as follows : 
Upper extremity 46 cm. 
Lower extremity 24 cm. 
The measurements were taken in the case of the upper extremity 
from the tip of the shoulder to the end of the middle finger, and in the 
lower extremity from the perineum to the heel, thus following, for the 
sake of comparison, the method adopted by Fick. We find, therefore, 
that the upper extremity measured 80.7 per cent, of the total length of 
the body, whilst the lower extremity measured 42.1 per cent, of the 
height. The following table will give the percentages in a comprehen- 
sive manner, the figures indicating percentages of the total length of 
the body from the head to the heel : 
Upper Lower 
Extremity. Extremity. 
The present specimen of the Orang 80.7% 42.1% 
p.. ..fOrang “Jumbo” 75 - 2 % 38.3% 
^ 1 Orang “ Anton ” 73-6% 37 - 9 % 
Man 45 % 47 - 5 % 
Fick’s measurements were taken from adult animals, whilst my Orang 
was quite young. 
The remarkable elongation of the upper extremities in proportion to 
the body length is not characteristic of the Orang only, but of all the 
anthropoid apes. In the Gibbon this feature is even more marked than 
in the Orang or than in all other apes. It is interesting to note in this 
connection that the arms of negroes are proportionately longer than in the 
white races, this being, however, chiefly due to the increased length of 
the hand and forearm. Huxley tells us that the native Australians and 
other low races resemble the negro in this respect. One must note also 
that in this peculiarity anthropoid apes differ in a marked degree from 
