The first was named Rajah, the latter was called Dohong.

Rajah was a male orang, and about four years of age when received by us. His high and broad forehead, large eyes and general breadth of cranium and jaw marked him at once as belonging to the higher caste of orangs. Dealers and experts have no difficulty in recognizing at one glance an orang that has a good brain and good general physique from those which are thin-headed, narrow-jawed, weak in body and unlikely to live long.

At the Zoological Park we have tested out the orang-utan's susceptibility to training, and proven that the task is so simple and easy that even amateurs can accomplish much in a short time.

Desiring that several of our orangs should perform in public, we instructed the primate keepers to proceed along certain lines and educate them to that idea. Naturally, the performance was laid out to match our own possibilities. In a public park, where only a very little time can be devoted to training, we do not linger long over an animal that is either stupid or obstinate. Those which cannot be trained easily and quickly are promptly set aside as ineligible.

Without any great amount of labor, and with no real difficulty, our orangs were trained to perform the following simple acts:

1. To sit at table, and eat and drink like humans. This involved eating sliced bananas with a fork, pouring out milk from a teapot into a teacup, drinking out of a teacup, drinking out of a beer- bottle, using a toothpick, striking a match, lighting a cigarette, smoking and spitting like a man.

2. To ride a tricycle, or bicycle.

3. To put on a pair of trousers, adjust the suspenders, put on a sweater or coat, and a cap, reversing the whole operation after the performance.

4. To drive nails with a hammer.

5. Use a key to lock and unlock a padlock. The animal most proficient in this became able to select the right Yale key out of a bunch of half a dozen or more, with as much quickness and precision as the average man displays.

The orang Dohong learned to pedal and to guide a tricycle in about three lessons. He caught the two ideas almost instantly, and soon brought his muscles under control sufficiently to ride successfully, even under difficult conditions.

It was quickly recognized that our Rajah was a particularly good subject, and with him the keepers went farther than with the four others. From the first moment, the training operations were to him both interesting and agreeable. The animal enjoyed the work, and he entered into it so heartily that in two weeks he was ready to dine in public, somewhat after the manner of human beings.

A platform eight feet in height was erected in front of the Reptile House, and upon it were placed a table, a high chair such as small children use, and various dishes. To the platform a step- ladder led upward from the ground. Every day at four o'clock l.u.s.ty Rajah was carried to the exhibition s.p.a.ce, and set free upon the ground. Forthwith the keepers proceeded to dress him in trousers, vest, coat and cap. The moment the last b.u.t.ton had been fastened and the cap placed upon his head, he would promptly walk to the ladder, climb up to the platform, and in the most business-like way imaginable, seat himself in his chair at the table, all ready to dine.

He used a napkin, ate his soup with a spoon, speared and conveyed his sliced bananas with his fork, poured milk from a teapot into his teacup, and drank from his cup with great enjoyment and decorum. When he took a drink (of tea) from a suspicious-looking black bottle, the audience always laughed. When he elevated the empty bottle to one eye and looked far into it, they roared; and when he finally took a toothpick and gravely placed it in his mouth, his auditors were delighted. Several times during the progress of each meal, Rajah would pause and benignly gaze down upon the crowd, like a self-satisfied judge on his bench.

Not once did Rajah spoil this exhibition, which was continued throughout an entire summer, nor commit any overt act of impatience, indifference or meanness. The flighty, nervous temper of the chimpanzee was delightfully absent. The most remarkable feature of it all was his very evident enjoyment of his part of the performance, and his sense of responsibility to us and to his audiences.

Rajah easily and quickly learned to ride a tricycle, and guide it himself. But for his untimely death, through a remarkable invasion of a microscopic parasite (_Balentidium coli_) imported from the Galapagos Islands by elephant tortoises, his mind would have been developed much farther. Since his death, in 1902, we have had other orang-utans that were successfully taught to dine, but none of them entered into the business with the same hearty zest which characterized Rajah, and made his performances so interesting.

We now come to a consideration of simian mental traits of very different character. Another male orang, named Dohong, of the same age and intellectual caste as Rajah, developed a faculty for mechanics and invention which not only challenged our admiration, but also created much work for our carpenters. He discovered, or invented, as you please, the lever as a mechanical force,--as fairly and squarely as Archimedes discovered the principle of the screw.

Moreover, he delighted in the use of the new power thus acquired, quite as much as the successful inventor usually does. At the same time, two very bright chimpanzees of his own age, and with the same opportunities, discovered nothing.

[Ill.u.s.tration caption: THUMB-PRINT OF AN ORANG-UTAN A group of fourteen experts in the New York City Departement of Criminal Records were unable to recognise this thumb print as anything else than that of a man]

[Ill.u.s.tration caption: "RAJAH," THE ACTOR ORANG-UTAN In three lessons he learned to ride a tricycle]

Dohong was of a reflective turn of mind, and never was entirely willing to learn the things that his keepers sought to teach him.

To him, dining at a table was tiresomely dull, and the donning of fashionable clothing was a frivolous pastime, On the other hand, the interior of his cage, and his gymnastic appliances of ropes, trapeze and horizontal bars, all interested him greatly. Every square inch of surface, and every piece of material in his apartment, was carefully investigated, many times over.

When three years old he discovered his own strength, and at first he used it good-naturedly to hector his cage-mate, a female chimpanzee smaller than himself. That, however, was of trifling interest. The day on which he made the discovery that he could break the wooden one and one-half inch horizontal bars that were held out from his cage walls on cast iron brackets, was for him a great day. Before his discovery was noted by the keepers he had joyfully destroyed two bars, and with a broken piece used as a lever was attacking a third. These bars were promptly replaced by larger bars, of harder wood, but screwed to the same cast-iron brackets that had carried the first series.

For a time, the heavier bars endured; but in an evil moment the ape swung his trapeze bar, of two-inch oak, far over to one side of his cage, and applied the bar as a lever, inside of a horizontal bar and from above. The new force was too much for the cast-iron brackets, and one by one they gave way. Some were broken off, and others were torn from the wall by the breaking of the screws that held them. Knowing that all those brackets must be changed immediately, Dohong was left to destroy them; which he did, promptly and joyfully. We then made heavy brackets of flat wrought iron bars, 1/2 by 21/2 inches, unbreakable even with a lever. These were screwed on with screws so large and heavy that our carpenters knew they were quite secure.

[Ill.u.s.tration caption: THE LEVER THAT OUR ORANG-UTAN INVENTED, AND THE WAY HE APPLIED IT By W. A. Camadeo, in the "Scientific American," 1907]

In due time, Dohong tested his lever upon the bars with their new brackets, and at first they held securely. Then he engaged Polly, his chimpanzee companion, to a.s.sist him to the limit of her strength. While Dohong pulled on the lever, Polly braced her absurd little back against the wall, and pushed upon it, with all her strength. At first nothing gave way. The combined strength exerted by the three brackets was not to be overcome by prying at the horizontal bar itself. It was then that Dohong's inventive genius rose to its climax. He decided to attack the brackets singly, and conquer them one by one. On examining the situation very critically, he found that each bracket consisted of a right- angled triangle of wrought iron, with its perpendicular side against the wall, its base uppermost, and its hypotenuse out in the air. Through the open centre of the triangle he introduced the end of his trapeze bar, chain and all, as far as it would go, then gave a mighty heave. The end of his lever was against the wall, and the power was applied in such a manner that few machine screws could stand so great a strain. One by one, the screws were torn out of the wood, and finally each bracket worked upon was torn off.

But there was one exception. The screws of one bracket were so firmly set in a particularly hard strip of the upright tongued- and-grooved yellow pine flooring that formed the wall, the board itself was finally torn out, full length! The board was four inches wide, seven-eighths of an inch thick, and seven feet long.

Originally it was so firmly nailed that no one believed that it could be torn from its place. [Footnote: In the Winter of 1921 about a dozen newspapers in the United States published a sensational syndicated article, occupying an entire page, in which all of Dohong's lever discovery and cage-wrecking performances were reported as of recent occurrence, and credited to a stupid and uninteresting young orang called Gabong, now in the Zoological Park, that has not even the merit of sufficient intelligence to maintain a proper state of bodily uprightness, let alone the invention of mechanical principles.]

Without delay, Dohong started in with his lever to pry off the remaining boards of the wall, but this movement was promptly checked. Our next task consisted in making long bolts by which the brackets of the horizontal bars were bolted entirely through the part.i.tion walls and held so powerfully on the other side that even the lever could not wreck them.

As soon as the brackets were made secure, Dohong turned his attention to the two large sleeping boxes which were built very solidly on the balcony of his cage. Both of those structures he tore completely to pieces,--always working with the utmost good nature and cheerfulness. Realizing that they could not exist in the cage with him, we gave him a permit to tear them out--and save the time of the carpenters.

Dohong's use of his lever was seen by hundreds of visitors, and one frequent visitor to the Park, Mr. L. A. Camacho, an engineer, was so much impressed that he published in the _Scientific American_ an ill.u.s.trated account of what he saw.

For a long period, Dohong had been more or less annoyed by the fact that he could not get his head out between the front bars of his cage, and look around the part.i.tion into the home of his next- door neighbor. Very soon after he discovered the use of the lever, he swung his trapeze bar out to the upper corner of his cage, thrust the end of it out between the first bar and the steel column of the part.i.tion, and very deftly bent two of the iron bars outward far enough so that he could easily thrust his head outside and have his coveted look.

One of our later and largest orangs made a specialty of twisting the straw of his bedding into a rope six or seven feet long, then throwing it over his trapeze bar and swinging by it, forward and back.

Time and s.p.a.ce will not permit the enumeration of the various things done by that ape of mechanical mind with his swinging rope and his trapeze, with ropes of straw _twisted by himself,_ with keys, locks, hammer, nails and boxes. Any man who can witness such manifestations as those described above, and deny the existence in the animal of an ability to reason from cause to effect, must be prepared to deny the evidence of his own senses.

The individual variations between orangs, as also between chimpanzees, are great and striking. It may with truth be said that no two individuals of either species are really quite alike in physiognomy, temperament and mental capacity. As subjects for the experimental psychologist, it is difficult to see how any other could be found that would be even a good second in living interest to the great apes. The facts thus far recorded, so I believe, present only a suggestion of the rich results that await the patient scientific investigator. In the year 1915 Dr. Robert M. Yerkes, of Harvard University, conducted at Montecito, southern California, in a comfortable primate laboratory, six months of continuous and diligent experiments on the behavior of orang-utans and monkeys. His report, published under the t.i.tle of "The Mental Life of Monkeys and Apes: A Study of Ideational Behavior," is a doc.u.ment of much interest and value. Dr. Yerkes'

use of the orang-utan as a subject was a decided step forward in the study of "animal behavior" in America.

IX

THE MAN-LIKENESS OF THE CHIMPANZEE

During the past twenty years, millions of thinking people have been startled, and not a few shocked, by the amazing and uncanny human-likeness of the performances of trained chimpanzees on the theatrical stage. Really, when a well trained "chimp" is dressed from head to foot like a man, and is seen going with quickness, precision and spirit through a performance half an hour in length, we go away from it with an uncomfortable feeling that speech is all that he lacks of being a citizen.

In 1904 the American public saw Esau. Next came Consul,--in about three or four separate editions! In 1909 we had Peter. Then came I know not how many more, including the giant Casey and Mr. Garner's Susie; and finally in 1918 our own Suzette. The theatre-going public has been well supplied with trained chimpanzees, and the mental capacity of that species is now more widely known and appreciated than that of any other wild animal except the Indian elephant.

There are several reasons why chimpanzees predominate on the stage, and why so few performing orang-utans have been seen. They are as follows:

1. The orang is sanguine, and slower in execution than the nervous chimpanzee.

2. The feet of the orang are not good for shoes, and biped work.

3. The orang is rather awkward with its hands, and finally,

4. There are fully twice as many chimps in the market.

But the chimpanzee has certain drawbacks of his own. His nervous temper and his forced-draught activities soon wear him out. If he survives to see his sixth or seventh year, it is then that he becomes so strong and so full of ego that he becomes dangerous and requires to be retired.

Bright minds are more common among the chimpanzee species than among the orangs. Three chimps out of every five are good for training, but not more than two orangs out of five can be satisfactorily developed.

Some sensitive minds shrink from the idea that man has "descended"

from the apes. I never for a moment shared that feeling. I would rather descend from a clean, capable and bright-minded genus of apes than from any unclean, ignorant and repulsive race of the genus _h.o.m.o._ In comparing the chimpanzees of Fernan Vaz with the Canoe Indians of the Strait of Magellan and other human tribes we could name, I think the former have decidedly the best of it. There are millions of members of the human race who are more loathsome and repulsive than wild apes.

The face of the chimpanzee is highly mobile, and the mouth, lips, eyes and voice express the various emotions of the individual with a degree of clearness and precision second only to the facial expression of man himself. In fact, the face of an intelligent chimpanzee or orang-utan is a fairly constant index of the state of mind of the individual. In their turn, those enormously expansive lips and keen brown eyes express contentment, doubt, fear and terror; affection, disapproval, jealousy, anger, rage; hunger and satiety; lonesomeness and illness.

The lips of the chimpanzee afford that animal several perfectly distinct expressions of the individual's mind and feelings. While it is not possible to offer a description of each which will certainly be recognizable to the reader, the two extremes will at least be appreciated. When coaxing for food, or attention, the lips are thrust far out beyond the teeth, and formed into a funnel with the small end outermost. When the chimpanzee flies into a rage at some real or fancied offense, the snarling lips are drawn back, and far up and down, until the teeth and gums are fully exposed in a ghastly threat of attack. At the same time, the voice gives forth shrill shrieks of rage, correctly represented by the syllable "Ee-ee-ee!", prolonged, and repeated with great force, three or four times. On such occasions as the latter, the offending party must look out for himself, or he may be roughly handled.