When taken out of the cage Aaron had special delight in driving the cow away; and if she was around he would grasp me by the hand and start towards her. He would stamp the ground with his foot, strike with all force with his long arm, slap the ground with his hand, and scream at her at the top of his voice. If she moved away, he would let go my hand and rush towards her as though he intended to tear her up; but if the cow turned suddenly towards him, the little fraud would run to me, grasp my leg, and scream with fright. The cow was afraid of a man, and as long as she was followed by one she would continue to go; but when she discovered the ape to be alone in the pursuit, she would turn and look as if trying to determine what manner of thing it was. Elisheba never seemed to take any special notice of the cow except when she approached too near the cage, and then it was due to the conduct of Aaron that she made any fuss about it.

On board the steamer in which we sailed for home there was a young elephant that had been sent by a trader, for sale. He was kept on deck in a strong stall built for his quarters. There were wide cracks between the boards, and the elephant had the habit of reaching his trunk through them in search of anything he might find. With his long, flexible proboscis extended, he would twist and coil it in all manner of writhing forms. This was the crowning terror of the lives of those two apes; it was the bogie-man of their existence, and nothing could induce either of them to go near it. If they saw me approach it, they would scream and yell until I came away. If Aaron could get hold of me without getting too near the elephant, he clung to me until he almost tore my clothes, to keep me away from it. It was the one thing that Elisheba was afraid of, and the only one against which she ever gave me warning.

They did not manifest the same concern for others, but sat watching them without offering any protest. Even the stowaway who fed them and attended to their cage was permitted to approach the elephant; but their solicitude for me was remarked by every man on board. I was never able to tell what their opinion of the thing was. They were much less afraid of the elephant when they could see all of him, than they were of the trunk when they saw that alone. They may have thought the latter to be a big snake; but this is only a conjecture.

At the beginning of the voyage I took six panels of my own cage and made a small cage for them. I taught them to drink water from a beer bottle with a long neck that could be put through a mesh of the wires. They preferred this mode of drinking and appeared to look upon it as an advanced idea. Elisheba always insisted on being served first; being a female, her wish was complied with. When she had finished, Aaron would climb up by the wires and take his turn. There is a certain sound, or word, which the chimpanzee always uses to express “good” or “satisfaction,” and he made frequent use of it. He would drink a few swallows of the water and then utter the sound, whereupon Elisheba would climb up again and taste. She seemed to think it something better than she was drinking, but finding it the same as she had had, she would again give way for him. Every time he used the sound she would take another taste and turn away; but she never failed to try it if he uttered the sound.

The boy who cared for them on the voyage was disposed to play tricks on them. One of these ugly pranks was to turn the bottle up so that when they had finished drinking and took their lips away, the water would spill out and run down over them. Several times they declined to drink from the bottle while he was holding it, but when he let it go, it hung in such a position that they could not get the water out of it at all. At length Aaron solved the problem by climbing up one side of the cage and getting on a level with the bottle; then he reached across the angle formed by the two sides of the cage and drank. In this position it was no matter to him how much the water ran out; it couldn’t touch him. Elisheba watched him until she quite grasped the idea; then she climbed up in the same manner and slaked her thirst. I scolded the boy for serving them with such cruel tricks; but it taught me another lesson of value concerning the mental resources of the chimpanzee, for no philosopher could have found a much better scheme to obviate the trouble than did this cunning little sage in the hour of necessity.

I have never regarded the training of animals as the true measure of their mental powers. The real test is to reduce the animal to his own resources, and see how he will conduct himself under conditions that present new problems. Animals may be taught to do many things in a mechanical way, and without any motive that relates to the action; but when they can work out the solution without the aid of man, it is only the faculty of reason that can guide them.

One thing that Aaron could never figure out was—what became of the chimpanzee that he saw in a mirror. I have seen him hunt for that mysterious ape an hour at a time. He once broke a piece off a mirror I had in trying to find the other fellow, but he never succeeded. I have held the glass firmly before him, while he put his face up close to it—sometimes almost in contact. He would quietly gaze at the image and then reach his hand around the glass to feel for it. Not finding it, he would peep around the side of the glass and then look into it again. He would take hold of it and turn it around, lay it on the ground, look at the image again, and put his hand under the edge of the glass. The look of inquiry in that quaint face was so striking as to make one pity him. But he was hard to discourage. He resumed the search whenever he had the mirror.

Elisheba never worried herself much about it. When she saw the image in the glass she seemed to recognize it as one of her kind; but when it vanished she let it go without trying to find it. In fact, she often turned away from it as though she did not admire it. She rarely ever took hold of the glass, and she never felt behind it for the other ape.

Altogether Elisheba was an odd specimen of her tribe—eccentric and whimsical beyond anything I have ever known among animals; yet, with all her freaks, Aaron was fond of her and she afforded him company; but he was extremely jealous of her, and permitted no stranger to take any liberties with her with impunity. He did not object to their doing so with him. He rarely took offense at any degree of familiarity, for he would make friends with any one who was gentle with him; but he could not tolerate their attentions to her. She betrayed no sign of affection for him except when some one annoyed or vexed him; but in that event she never failed to take his part against all odds. At such times she became frantic with rage, and if the cause was prolonged, she often for hours afterwards refused to eat.

On the voyage homeward there was on board another chimpanzee, belonging to a sailor who was bringing him home for sale. This one was about two years older than Aaron and fully twice as large. He was tame and gentle, but was kept in a close cage by himself. He saw the others roaming about the deck and tried to make up with them; but they evinced no desire to become intimate with one who was confined in such a manner.