The Marvelous Beaver. Let us consider this animal as an illuminating example of high-power intelligence.
In domestic economy the beaver is the most intelligent of all living mammals. His inherited knowledge, his original thought, his reasoning power and his engineering and mechanical skill in constructive works are marvelous and beyond compare. In his manifold industrial activities, there is no other mammal that is even a good second to him. He builds dams both great and small, to provide water in which to live, to store food and to escape from his enemies. He builds air-tight houses of sticks and mud, either as islands, or on the shore. When he cannot live as a pond-beaver with a house he cheerfully becomes a river-beaver. He lives in a river-bank burrow when house-building in a pond is impossible; and he will cheerfully tunnel under a stone wall from one-pond monotony, to go exploring outside.
[Illustration: CHRISTMAS AT THE PRIMATES' HOUSE Chimpanzees (with large ears) and orang-utans (small ears). The animal on the extreme right is an orang of the common caste]
He cuts down trees, both small and large, and he makes them fall as he wishes them to fall. He trims off all branches, and leaves no "slash" to cumber the ground. He buries green branches, in great quantity, in the mud at the bottom of his pond, so that in winter he can get at them under a foot of solid ice. He digs canals, of any length he pleases, to float logs and billets of wood from hinterland to pond.
If you are locating beavers in your own zoo, and are wise, you can induce beavers to build their dam where you wish it to be. This is how we did it!
We dug out a pond of mud in order that the beavers might have a pond of water; and we wished the beavers to build a dam forty feet long, at a point about thirty feet from the iron fence where the brook ran out. On thinking it over we concluded that we could manage it by showing the animals where we wished them to go to work.
We set a l2-inch plank on its edge, all the way across the dam site, and pegged it down. Above it the water soon formed a little pool and began to flow over the top edge in a very miniature waterfall. Then we turned loose four beavers and left them.
The next morning we found a cart-load of sticks and fresh mud placed like a dam against the iron fence. In beaver language this said to us:
"We would rather build our dam here,—if you don't mind. It will be easier for us, and quicker."
We removed all their material; and in our language that action said: "No; we would rather have you build over the plank."
The next night more mud and sticks piled against the fence said to us,
"We really insist upon building it here!"
We made a second clearance of their materials, saying in effect:
"You shall not build against the fence! You must build where we tell you!"
Thereupon, the beavers began to build over the plank, saying,
"Oh, well, if you are going to make a fuss about it, we will let you have your way."
So they built a beautiful water-tight dam precisely where we suggested it to them, and after that our only trouble was to keep them from overdoing the matter, and flooding the whole valley.
I am not going to dwell upon the mind and manners of the beaver. The animal is well known. Three excellent books have been written and pictured about him, in the language that the General Reader understands. They are as follows: "The American Beaver and His Works," Lewis H. Morgan (1868); "The Romance of the Beaver," A. R. Dugmore (no date); "History and Traditions of the Canada Beaver," H. T. Martin (1892).
"Clever Hans," the "Thinking Horse." From 1906 to 1910 the world read much about a wonderful educated horse owned and educated by Herr von Osten, in Germany. The German scientists who first came in touch with "Hans" were quite bowled over by the discovery that that one horse could "think." The Review of Reviews said, in 1910:
"It may be recalled that Clever Hans knew figures and letters, colors and tones, the calendar and the dial, that he could count and read, deal with decimals and fractions, spell out answers to questions with his right hoof, and recognize people from having seen their photographs. In every case his 'replies' were given in the form of scrapings with his right forehoof.
"Whether the questioner was von Osten, who had worked with him for seven years, or a man like Schillings, who was a complete stranger, seemed immaterial; and this went farthest, perhaps, in disposing of all talk of 'collusion' between master and beast."
Now, by the bald records of the case the fact was fixed for all time that Hans was the most wonderful mental prodigy that ever bore the form of a four-footed animal. His learning and his performances were astounding, and even uncanny. I do not care how he was trained, nor by what process he received ideas and reacted to them! He was a phenomenon, and I doubt whether this world ever sees his like again. His mastery of figures alone, no matter how it was wrought, was enough to make any animal or trainer illustrious.
But eventually Clever Hans came to grief. He was ostensibly thrown off his pedestal, in Germany, by human jealousy and egotism. Several industrious German scientists deliberately set to work to discredit him, and they stuck to it until they accomplished that task. The chief instrument in this was no less a man than the director of the "Psychological Institute" of the Berlin University, Professor Otto Pfungst. He found that when Hans was put on the witness stand and subjected to rigid cross examinations by strangers, his answers were due partly to telepathy and hypnotic influence! For example, the discovery was made that Hans could not always give the correct answer to a problem in figures unless it was known to the questioner himself.
To Hans's inquisitors this discovery imparted a terrible shock. It did not look like "thinking" after all! The mental process was different from the process of the German mind! The wonderful fact that Hans could remember and recognize and reproduce the ten digits was entirely lost to view. At once a shout went up all over Germany,—in the scientific circle, that Hans was an "impostor," that he could not "think," and that his mind was nothing much after all.
Poor Hans! The glory that should have been his, and imperishable, is gone. He was the victim of scientists of one idea, who had no sense of proportion. He truly WAS a thinking horse; and we are sure that there are millions of men whose minds could not be developed to the point that the mind of that "dumb" animal attained,—no, not even with the aid of hypnotism and telepathy.
The bare fact that a horse can be influenced by occult mental powers proves the close parallelism that exists between the brains of men and beasts. The Trap-Door Spider. Let no one suppose for one moment that animal mind and intelligence is limited to the brain-bearing vertebrates. The scope and activity of the notochord in some of the invertebrates present phenomena far more wonderful per capita than many a brain produces. Interesting books have been written, and more will be written hereafter, on the minds and doings of ants, bees, wasps, spiders and other insects.
Consider the ways and means of the ant-lion of the East, and the trap-door spider of the western desert regions. As one object lesson from the insect world, I will flash upon the screen, for a moment only, the trap-door spider. This wonderful insect personage has been exhaustively studied by Mr. Raymond L. Ditmars, in the development of a series of moving pictures, and at my request he has contributed the following graphic description of this spider's wonderful work.
"The trap-door spiders, inhabiting the warmer portions of both the Old and New Worlds, dig a deep tunnel in the soil, line this with a silken wallpaper, then construct a hinged door at the top so perfectly fitted and camouflaged with soil, that when it is closed there is no indication of the burrow. Moreover, the inside portion of the door of some species is so constructed that it may be "latched," there being two holes near the edge, precisely placed where the curved fangs may be inserted and the door held firmly closed. Also, the trap-door of a number of species is so designed as to be absolutely rain-proof, being bevelled and as accurately fitting a corresponding bevel of the tube as the setting of a compression valve of a gasolene engine.
[Illustration: THE TRAP-DOOR SPIDER'S DOOR AND BURROW By R. L. Ditmars