“The following day, April 3, Gertie was lured from her cage to a large adjoining compartment for certain experimental observations.  After she had been returned to her own cage the remnant was noticed on the floor of the large cage.  I picked it up.  Gertie evidently noticed my act; for although at a distance of at least ten feet from me, she made a sharp outcry and sprang to the side of the cage nearest me.  I held the piece of skin (it looked more like a bit of rat skin than the remains of a monkey) out to her and she immediately seized it and rushed with it to the shelf at the top of the cage.

“Two days later the remnant was missing, and careful search failed to discover it in the cage.  It is probable that Gertie had carelessly left it lying on the floor whence it was washed out when the cages were cleaned.  On this date Gertie seemed quieter than for weeks previously.

“Thus it appears that during a period of five weeks the instinct to protect her offspring impelled this monkey to carry its gradually vanishing remains about with her and to watch over them so assiduously that it was utterly impossible to take them from her except by force.

“After reading this note in manuscript, Doctor Hamilton informed me that
Gertie had behaved toward her first still-birth as toward her second. 
And, further, that Grace, a baboon, also carried a still-birth about for
weeks.

“I am now heartily glad that my early efforts to remove the corpse were futile, for this record of the persistence of maternal behavior seems to me of very unusual interest to the genetic psychologist.”

Fear

In connection with the multiple-choice experiments Skirrl exhibited what seemed to be instinctive fear as a result of his unfortunate experience with nails in the floor of box 1.  He seemingly referred his misadventure to some unseen enemy under the floor, and this in spite of the fact that he was given abundant opportunity to examine the floor of the box, but not until after 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