It is true that she was in poor health, and had been badly treated before she fell into my hands, but she was by nature endowed with a bad temper and depraved instincts. It is not at all rare to see a vast difference of manners, intelligence, and temperament among specimens that belong to one species. In these respects they vary as much in proportion to their mental scope as human beings do; but I have never seen, in any two apes of the same species, the two extremes so widely removed from one another. While waiting at Gaboon for a steamer I had my own cage erected for them to live in, as it was large and gave them ample room for play and exercise. In one corner of it was suspended a small, cosy house for them to sleep in. It was furnished with a good supply of clean straw and some pieces of canvas for bed-clothes. In the centre of the cage was a swing, or trapeze, for them to use at their pleasure. Aaron found this a means of amusement, and often indulged in a series of gymnastics that would evoke the envy of the king of athletic sports. Elisheba had no taste for such pastime, but her depravity could never resist the impulse to interrupt him in his jolly exercise. She would climb up and contend for possession of the swing until she would drive him away, when she would perch herself on it and sit there for a time in stolid content, but would neither swing nor play. Frequently, when Aaron would lie down quietly on the straw during the day, she would go into the snug little house and raise a row with him by pulling the straw from under him, handful at a time, and throwing it out of the box till there was not one left in it. No matter what kind or quantity of food was given them, she always wanted the piece he had, and would fuss with him to get it; but when she got it, she would sit holding it in her hand without eating it, for there were some things that he liked which she would not eat at all. When we went out for a walk, no matter which way we started she always contended to go some other way; and if I yielded, she would again change her mind, and start off in some other direction. If forced to submit, she would scream and struggle as if for life. I cannot forego the belief that these freaks were due to a base and perverse nature, and I could find no higher motive in her stubborn conduct. Aaron was very fond of her, and rarely ever opposed her inflexible will. He clung to her, and let her lead the way. I have often felt vexed at him because he complied so readily with her wishes. The only case in which he took sides against her was in her conduct towards me.