Activities_

In more respects than I have taken time to enumerate in the above
descriptions of behavior, the relations of Sobke to objects differed
from those of Skirrl, and still more from those of Julius. Hammer,
nails, saw, stones, sticks, locks, and various other objects received
relatively little attention from Sobke unless they happened to come in
his way; then they were usually pushed aside with but scant notice.
Rarely he would carry something to the shelf of his cage with him, but
as a rule only to lay it down and attend to something else. Skirrl, on
the contrary, attended persistently to anything new in the shape of a
movable object. He was extremely partial to objects which could be
manipulated by him in various ways, and especially to any thing with
which he could make a noise. His interest in hammer and nails, saw,
locks, etc., seemed never to wane. I have seen him play for an hour
almost uninterruptedly with a hammer and a nail, or even with a big
spike which he could use to pry about his cage. In the absence of
anything more interesting, even a staple or a small nail might receive
his undivided attention for minutes at a time. How important is the
species difference in this connection, I have no means to judge, but if
we may not consider these different modes of behavior characteristic of
_P. rhesus_ as contrasted with _P. irus_, we must conclude that
remarkable individual differences exist among monkeys, for whereas
Skirrl is by nature a mechanical genius, Sobke has apparently no such
disposition. I can imagine no more fascinating task than the careful
analytical study of the temperaments of these two animals. Skirrl's
behavior has importantly modified my conception of genius.

V

MISCELLANEOUS OBSERVATIONS

1. _Right- and left-handedness_

Several years ago Doctor Hamilton reported to me observations which he
had made on preference for the right or left paw in dogs. He has not, I
believe, published an account of his work. Subsequently, Franz observed
a similar preference in monkeys which, according to his report, exhibit
marked tendency to be right-handed, left-handed, or ambidextrous.

My own observations, although they are wholly incidental to my other
work, seem worthy of description at this point. I noted, first of all,
that the orang utan Julius tended to use his left hand. He by no means
limited himself to this, but in difficult situations he almost
invariably reached for food or man