aving restrained their natural tendency and desire to escape,
when they could so easily gratify such a desire or tendency, is a potent
factor in an argument for their possession of the ratiocinative
faculty. Their teacher explained that he "brought them to reason" by
keeping them at first in a glass vessel, where they jumped and bumped
their heads to no purpose against the transparent walls of their prison.
Thus their vaulting ambition was held in check, and they learned to
reason from cause and effect.

It is a well-known fact that many of the higher animals can be taught to
do many things entirely foreign to their natures. This is brought about
entirely through the faculty of remembering events. I am confident that
many of the lower animals, insects, crustaceans, reptiles, are likewise
the possessors of this faculty, and are capable of being taught. I,
myself, have succeeded in teaching a toad to hop over a stick at the
word of command. Again, I taught two chameleons to take certain
positions and to retain them at feeding time. These little creatures
remembered their lesson, and at my whistle would "line up" on the
particular book that I had designated as their dining-table. We have
seen that fleas are capable of being highly educated, hence it is
reasonable to presume that other insects, specially and generically akin
to the flea, likewise possess the faculty of remembering events. Of
course, this faculty is necessarily more highly developed in some
animals than in others; it differs in degree of development, not in
kind.

CHAPTER IV

THE EMOTIONS

Careful observation and investigation lead me to believe that, in many
of the higher animals, all the fundamental emotions, such as love, hate,
fear, anger, jealousy, etc., are present. Books on natural history
fairly teem with data in support of this proposition. Such authorities
as Romanes,[41] Darwin,[42] Semper[43] and Hartman[44] give instance
after instance in support of the dictum that the emotional nature of
many of the higher animals is highly developed.

[41] Romanes, _Animal Intelligence_.

[42] Darwin, _Descent of Man_.

[43] Semper, _Animal Life_.

[44] Hartmann, _Anthropoid Apes_.

Man has been called the Laughing Animal, because, so it has been
claimed, he alone of all animals expresses emotion through the agency of
the smile or through laughter.

This is a grave mistake, for both the dog and the monkey, in certain
instances, ha