.

3. A distinct preference for the right hand in violent efforts in
reaching became noticeable in the seventh and eighth months.
Experiments during the eighth month on this cue gave, in 80 cases,
right hand, 74 cases; left hand, 5 cases; both hands, 1 case. This was
true in two very distinct classes of cases: first, reaching for
objects, neutral as regards colour (newspaper, etc.), at more than the
reaching distance; and, second, reaching for bright colours at any
distance. Under the stimulus of bright colours, from 86 cases, 84 were
right-hand cases and 2 left-hand. Right-handedness had accordingly
developed under pressure of muscular effort in the sixth and seventh
months, and showed itself also under the influence of a strong colour
stimulus to the eye.

4. Up to this time the child had not learned to stand or to creep;
hence the development of one hand more than the other is not due to
differences in weight between the two longitudinal halves of the body.
As she had not learned to speak or to utter articulate sounds with
much distinctness, we may say also that right or left-handedness may
develop while the speech centres are not yet functioning. Further, the
right hand is carried over after objects on the left side, showing
that habit in reaching does not determine its use.

_Theoretical_.--Some interesting points arise in connection with the
interpretation of these facts. If it be true that the order of rise of
mental and physiological functions is constant, then for this question
the results obtained in the case of one child, if accurate, would hold
for others apart from any absolute time determination. We should
expect, therefore, that these results would be confirmed by
experiments on other children, and this is the only way their
correctness can be tested.

If, when tested, they should be found correct, they would be
sufficient answer to several of the theories of right-handedness
heretofore urged, as has been already remarked. The rise of the
phenomenon must be sought, therefore, in more deep-going facts of
physiology than such theories supply. Furthermore, if we go lower in
the animal scale than man, analogies for the kinds of experience which
are urged as reasons for right-handedness are not present; animals do
not carry their young, nor pat them to sleep, nor do animals shake
hands!

A full discussion would lead us to the conclusion that dextrality is
due to a difference in development in the two he