muscles contract. The first slight raisings of the head are like the
first kicking movements, merely impulsive; but the child soon sees the
advantage of this apparently accidental movement and tries to master
it. Preyer[A] considers that the efforts to balance the head among the
first indications that the child's will is taking possession of his
muscles. His own boy arrived at this point when he was between three
and four months old.

[Sidenote: Reflex Grasping]

The grasp of the new-born baby's hand has a surprising power, but the
baby himself has little to do with it. The muscles act because of
a stimulus presented by the touch of the fingers, very much as the
muscles of a decapitated frog contract when the current of electricity
passes over them. This is called reflex grasping, and Dr. Louis
Robinson,[B] thinking that this early strength of gasp was an
important illustration of and evidence for evolution, tried
experiments on some sixty new-born babies. He found that they could
sustain their whole weight by the arms alone when their hands were
clasped about a slender rod. They grasped the rod at once and could
be lifted from the bed by it and kept in this position about half a
minute. He argued that this early strength of arm, which soon begins
to disappear, was survival from the remote period when the baby's
ancestors were monkeys or monkey-like people who lived in trees.

[Sidenote: Beginnings Of Will Power]

However this may be, during the first week the baby's hands are much
about his face. By accident they reach, the mouth, they are sucked;
the child feels himself suck its own fist; he feels his fist being