r the dangerous nails had been clinched. His long
continued avoidance of the experiment boxes and his still more
persistent hesitancy in entering them, coupled with his almost ludicrous
efforts to see beneath the floor through the holes cut for the staples
on the doors, gave me the impression of superstitious fear of the
unseen. As I watched and recorded his behavior day after day during the
period of most pronounced fear, I could not avoid the thought that the
instinctive fear of snakes had something to do with his peculiar
actions, and although I have never studied either the natural or the
acquired responses of monkeys to snakes, I suspect that lacking such
instinctive equipment, Skirrl would have behaved differently as a result
of the pricks which he received from the nails. It is needless to
redescribe his acquired fear of whiteness as it manifested itself in the
freshly painted apparatus. Accompanying these instructive modes of
response and their emotions are suggestions of peculiarly interesting
problems as well as of modes of attacking them. As a matter of fact,
Skirrl's fear-reactions did much to alter my conception of the
constitution of his mind. I should not have been surprised by the
features of behavior exhibited, but I was by no means prepared for their
persistence, and for the highly emotional attitude toward the particular
situation. Only an organism of complexly constituted nervous system and
fairly highly developed affective life could be expected to respond as
did this monkey. As has been suggested above, I find the appeal to
instinct, modified by experience, a natural mode of accounting for the
unexpected features of Skirrl's behavior.

_Sympathy_

The instinctive playfulness of the young monkey Tiny contrasted most
strikingly with the more serious, if not more sedate, modes of behavior
of the older individuals.

During the greater part of my period of observation Tiny was cage-mate
of Scotty, the most calm and apparently lazy of all the monkeys. Tiny
delighted in teasing Scotty, and her varied modes of mildly tormenting
him and of stirring him to pursuit or to retaliation were as interesting
as they were amusing. Her most common trick was to steal up behind him
and pull the hair of his back, or seize his tail with her hands or
teeth. Often when he was asleep she would suddenly run to him, give a
sudden jerk at a handful of hairs, and leap away. He was surprisingly
patient, and I never saw him