thus to push or pull the bar back. It worked very easily, a pressure of perhaps 15 grams being sufficient. On January 4, 1901, this box was put in No. I's cage. He failed to get in in 5 minutes, though he was active in trying to get in for about 4 minutes of the time and pulled and pushed the bar a great deal, though up and down and out instead of back. In his aimless pushings and pullings he nearly succeeded. He failed in 5 minutes in a second trial also. I then opened the door of the cage, sat down beside it, held out my hand, and when he came to me took his right paw and with it (he being held in front of the box) pushed the bar back (and pulled the door open in those cases when it did not fall open of itself). He reached in and took the food and went back to the top of his cage and ate it. I put him through the act thus 10 times. I then let him try alone. He failed to get in. In this and the two following days No. 1 was put through the act 80 times and given frequent opportunities to open the box himself. He never derived the slightest profit from the tuition.
No. 1 had eight such tests and No. 3 had six. Their behavior was in some cases ambiguous but the verdict would surely be that they had no general capacity to acquire these simple habits by seeing and feeling themselves make the movements and get food thereby.
The theoretical importance of the failure of the monkeys to learn from example or from being put through movements consists in the testimony it bears to their lack of a general fund of ideas. Adult human beings learn to do things by getting ideas of the circumstances and of the acts required and then proceeding to act upon these ideas. We think of where we are going, and so go; we have an idea of what we wish to do and so do it. Rarely if ever do monkeys learn in this way.
The behavior of the monkeys apart from these specific experiments seemed also to show their inability to acquire and use ideas of objects or acts. In getting them so that they would let themselves be handled, it was of almost no service to take them and feed them while holding them or otherwise make that state pleasant for them. By far the best way is to wait patiently till they do come near, then feed them; wait patiently till they do take hold of your arm, then feed them. If you do take them and hold them partly by force you must feed them only when they are comparatively still. In short in taming them one comes unconsciously to adopt the method of rewarding certain of their impulses rather than certain conditions which might be associated in their minds with ideas, had they such.
Monkey No. 1 apparently enjoyed scratching himself. Among the stimuli which served to set off this act of scratching was the irritation from tobacco smoke. If anyone blew smoke in No. I's face he would blink his eyes and scratch himself, principally in the back. After a time he got in the habit of coming to the front of his cage when anyone
