upon a branch higher up and seemed to pause to consider. The machines ceased to act. At this instant the mother-bird spied the hole that was the entrance to her nest and flew straight to it. Her treasures were found.
In that moment did she cease to be a machine, and show a spark of free intelligence? It looks so at least. She acted like a rational being, she seemed at last to have got it into her head that the nest was no longer in the old place, and that she must look about her. I do not say that this is the true explanation of her conduct; it is rather putting one's self in her place. But how long it took the birds to break out of the rut of habit! It did not seem as if their intelligence was finally influenced; but as if their instincts had become discouraged or fatigued. They were not convinced, they were baffled. Of course you cannot convince an animal as you can a person, because there is no reason to. be convinced; but you can make an impression, you can start the formation of a new habit. See the caged animal try to escape, or the tethered one try to break its tether,—how long the struggle continues! A rational being would quickly be convinced, and would desist. But instinct is automatic, and the reaction continues. When the animal ceases its struggles, it is not as the result of a process of ratiocination,—'this cage or this chain is stronger than I am, therefore I cannot escape,'—but because the force of instinct has spent itself. Man, too, is more or less the creature of habit, but the lower animals are almost entirely so. Only now and then, as in the case of the mother-bluebird, is there a gleam of something like the power of free choice.
Darwin quotes the case of a pike in an aquarium that for three months dashed itself with great violence against a plate-glass that separated it from the fish upon which it was wont to feed. Then, he says, it learned caution, and would not seize the fish when the glass was removed. It was not convinced, I should say, but another habit had been formed.
The whole secret of the training of wild animals is to form new habits in them. A certain regular, absolutely regular, routine must be kept up till the habit is formed of doing the trick. The animal does not learn the trick in a sense that implies the exercise of free intelligence: it is shaped to it as literally as the root of a tree shapes itself to a rock; or, we may say, it is trained as we train a tree against a wall.
Animal intelligence is like the figures and designs made in a casting; it is not acquired or much changed by experience, while human intelligence is slowly developed through man's educative capacity. The animal is a creature of habits inherited and acquired, in a sense that man is not; certain things may be stamped into the animal's mind, and certain things may be stamped out; we can train it into the formation of new habits, but we cannot educate or develop its mind as we can that of a child, so that it will know the why and the wherefore. It does the trick or the task because we have shaped its mind to the particular pattern; we have stamped in this idea, which is not an idea to the animal but an involuntary impulse. That which exists in the mind of man as mental concepts, free ideas, exists in the mind of the animal as innate tendency to do certain things. The bird has an impulse to build its nest, not any free or abstract ideas about nest-building; probably the building is not preceded or attended by any mental processes whatever, but by an awakening instinct, an inherited impulse.
A man can be reached and moved or influenced through his mind, an animal
