Morphology. 89 
ape, the outer margin of the other follows those of the 
chimpanzee and orang. Of course it would be easy 
to select individual human ears which present either 
of these characters in a more pronounced degree; 
but these ears have been chosen as models because 
they present both characters in conjunction. The 
upper row of figures likewise shows the close similarity 
of hair-tracts, and the direction of growth on the part 
of the hair itself, in cases where the human ear happens 
to be of an abnormally hirsute character. But this 
particular instance (which I do not think has been 
previously noticed) introduces us to the subject of hair, 
and hair-growth, in general. 
(8) Hair.—Adult man presents rudimentary hair 
over most parts of the body. Wallace has sought to 
draw a refined distinction between this vestigial coating 
and the useful coating of quadrumanous animals, in 
the absence of the former from the human back. But 
even this refined distinction does not hold. On the 
one hand, the comparatively hairless chimpanzee 
which died last year in the Zoological Gardens (7. 
calvus) was remarkably denuded over the back ; and, 
on the other hand, men who present a considerable 
development of hair over the rest of their bodies 
present it also on their backs and shoulders. Again, | 
jin all men the rudimentary hair on the upper and'| 
i lower arm is directed towards the elbow-~a peculiarity | 
which occurs nowhere else in the animal kingdom, | 
with the exception of the anthropoid apes and a few 
American monkeys, where it presumably has to do 
with arboreal habits. For, when sitting in trees, the 
orang, as observed by Mr. Wallace, places its hands 
above its head with its elbows pointing downwards: 
