192 
THE DESCENT OF MAH. 
Part I- 
wards, and the lower eyelids wrinkled. The external 
ears are curiously alike. In man the nose is much 
more prominent than in most monkeys ; hut we may 
trace the commencement of an aquiline curvature in 
the nose of the Hoolock Gibbon ; and this in the Sem- 
nopithecus nasioa, is carried to a ridiculous extreme. 
The faces of many monkeys are ornamented with 
beards, whiskers, or moustaches. The hair on the head 
grows to a great length in some species of Semno- 
pithecus ; 6 and in the Bonnet monkey ( Macacus 
radiatus) it radiates from a point on the crown, with a 
parting down the middle, as in man. It is commonly 
said that the forehead gives to man his noble and intel- 
lectual appearance ; but the thick hair on the head of 
the Bonnet monkey terminates abruptly downwards, 
and is succeeded by such short and fine hair, or down, 
that at a little distance the forehead, with the exception 
of the eyebrows, appears quite naked. It lias been 
erroneously asserted that eyebrows are not present in 
any monkey. In the species just named the degree of 
nakedness of the forehead differs in different individuals! 
and Eschricht states 7 that in our children the lin'd 
between the hairy scalp and the naked forehead 1 8 9 
sometimes not well defined ; so that here we seem to 
have a trifling case of reversion to a progenitor, in whom 
the forehead had not as yet become quite naked. 
It is well known that tho hair on our arms tends to 
converge from above and below to a point at the el bo" • 
This curious arrangement, so unlike that in most of the 
lower mammals, is common to the gorilla, chimpanzee, 
orang, some species of Hylobates, and even to some few' 
American monkeys. But in Hylobates agilis the ha" 
8 Isid. Geoffroy, ‘ Hist. Nat. Gen.’ tom. ii. 1850, p. 217. 
’ “ Ueber die Kichtung der Haare,” &c., Muller’s ‘ Areliiv fiir Ana 
und Phys.’ 1837, s. 51. 
