ation he is willing to admit. But
he insists that it is of surprisingly little importance in comparison
with what the general behavior of monkeys as known in captivity and as
described by the anecdotal writers have led us to expect. It is
important to note, however, that Thorndike's observations were limited
to Cebus monkeys which, as contrasted with various old world types, are
now considered of relatively low intelligence.

In many respects the most thoroughgoing and workmanlike experimental
study of monkeys is that of Kinnaman (1902), who has reported on the
study of various forms of response in _P. rhesus_. He presents valuable
data concerning the learning processes, sensory discrimination, reaction
to number, and to tests of imitation. His results indicate a higher
level of intelligence than that discovered by Thorndike, but this is
almost certainly due to difference in the species observed. Kinnaman
goes so far as to say "We have found evidence, also, of general notions
and reasoning, both of low order" (p. 211).

The contribution of Hobhouse (1915) to our knowledge of the mental life
of monkeys, although in a measure experimental, is based upon relatively
few and unsystematic observations as contrasted with those of Thorndike
and Kinnaman. It appears, however, that Hobhouse's experiments were
admirably planned to test the ideational capacity of his subjects, and
one can not find a more stimulating discussion of ideation than that
contained in his "Mind in Evolution." The results of his tests made with
a _P. rhesus_ monkey are similar to those of Kinnaman, for almost all of
them indicate the presence and importance of ideas.

Watson (1908) in tests of the imitative ability of _P. rhesus_ saw
relatively little evidence of other than extremely simple forms of
ideation. But in contrast with his results, those obtained by Haggerty
(1909), in a much more extended investigation in which several species
of monkey were used, obtained more numerous and convincing evidences of
ideation in imitative behavior. Although this author wholly avoids the
use of psychological terms, seeking to limit himself to a strictly
objective presentation of results, it is clear from an unpublished
manuscript (thesis for the Doctorate of Philosophy, deposited in the
Library of Harvard University) that he would attribute to monkeys simple
forms of ideational experience.

Witmer (1910) reports, in confirmation of Haggerty's results,
intellige