Table III. deals with the Method of Acquisition. It is con-
fined to the cats and dogs, and to those experiments in which
there was some suggestion of perceptual learning. It states the
method used by the experimenter (in which connection see the
general account, pp. 186 - 189 ), and compares the behaviour of
the animal at the first trial with the behaviour necessary for
success. When there was a distinct suggestion of some other
influence guiding the animal, that is noted.

Table IV. notes the definite cases of failure where the experi-
ment was fairly tried. Twelve trials distributed over more than
one day are taken as establishing a fair trial. In some cases I
have entered failures of special interest not fulfilling this condition.
Only animals appearing in the other tables are entered.

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