FEATURES OF HUMAN STRUCTURE 
without help from the arms. This duty, gradually enforced, has strength- 
ened, straightened, and nearly equalized the bones of the legs, extended 
the heel, and enlarged and arched the instep to bear the weight of the whole 
frame; while the toes, useful now only to help the foot in holding its place, 
and in pushing and balancing the body, when a step forward is taken, are 
short and strong, with the great toe squarely alongside the others. The 
arms are shortened, the hands extremely flexible and become the most 
perfect grasping organs, due mainly to the greater length and freedom of 
the thumb, for whose control have been developed one of the very few novel 
muscles possessed by man alone. To his hands, next to his brain, man 
owes the possibility of his great advancement. 
It is in the head, however, that the most striking human feature is seen, 
apart from the erect posture and accurate balance of the body upon its 
pillarlike legs. The skull is a dome poised beneath its center The Hu- 
instead of aft of it, as in the apes and lower creatures, and ™an Face. 
it contains twice as much brain room as does that of any other Primate. 
The frontal bones have been shortened and contracted until in the best 
examples the face protrudes little if any beyond the front line of the com- 
paratively lofty brow. The jaws have become semicircular in shape, the 
teeth small and crowded, the canines never much larger than the others, 
the chin is well filled out, the nose narrow but prominent and well separated 
from the mouth, and the eyes deeply set in comparatively small, bony” 
sockets, which do not enlarge inward, as in lower animals, to obstruct the 
brain case; while the ears are small, low, and set close to the head. Sev- 
eral of these features may be seen separately in various apes and monkeys, 
but their combination is perfected in man, and gives to his head a dignity, 
and to his countenance an expression, unmistakably his own. 
Man’s brain may be compared properly only with the brains of the an- 
thropoid apes. ‘The human brain differs from that of the manlike apes,” 
says Forbes,? “in regard to its convolutions and their separating grooves, 
only in minor characters; but in weight, as in capacity, very greatly. The 
weight of a healthy, full-grown human brain never descends below thirty- 
two ounces; that of the largest gorilla, far heavier than any man, never 
attains to more than twenty. Yet ‘the difference in weight of brain between 
the highest and the lowest men is far greater relatively and absolutely than 
between the lowest man and the highest ape.’ ” 
Some fossil bones found in 1894 in Java by Professor Eugene 
Du Bois are of extreme interest, because they represent a creature 
between man and the highest apes which lived in the early 
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