ch more acute in these. I have frequently
interlaced my fingers with those of some person whom they dislike, and
extending the hand towards them, they rarely make a mistake by getting
hold of the wrong finger, and yet it has frequently occurred that they
could not see the hands at all, and had to depend alone upon the sense
of touch. In cases where the hands were very nearly the same size they
were not able to select the fingers so readily, but where a lady's hand
was used, or that of a boy, the selection was made without hesitancy and
without error. I have tried this experiment a great many times with a
view to ascertaining to some extent the delicacy of their sense of
touch. Another fact that I may mention is, that they do not habitually
smell articles of food or other things given to them; but they depend
chiefly upon their sight for finding and their taste for choosing their
food. My opinion is, that the sense of smell does not play an important
part in these affairs. I may add, too, that, in the Cebus, his tail is
perhaps the most sensitive organ of touch, although it is not used in
this capacity to any great extent. He is generally very watchful over
this useful member, because it serves him in so many ways, and I think
perhaps it is safe to say that the tail is the last part of the monkey
that ever becomes tame.

CHAPTER XIII.

The Extent of my Experiments--Apes and Baboons--Miscellaneous
Records of Sound--The Vocal Index.

In quest of the great secret of speech, I have pursued my investigations
chiefly in the direction of learning one tongue, but incidentally I have
made many detours, and I have recorded the sounds of many other forms of
the animal kingdom, besides primates. I have examined the phonation of
lions, tigers, leopards, cats, dogs, birds of many kinds, and the human
voice in speech, music, and laughter. Besides these, I have examined
various musical sounds, especially of the pipe and whistle kinds.

More than a year ago I made some splendid records of the sounds of the
two chimpanzees in the Cincinnati collection. I have not had the
opportunity to study these apes themselves, as I desired to do, since
they are kept so closely confined in a glass house, and for ever under
the eye of their keeper, which conditions are not favourable to the best
results. I am not prepared therefore to give much detail concerning
their speech; but from a careful study of one cylinder containing a
reco