wasp finds its hole in the ground too small to admit the spider or other insect which it has brought, it falls to and enlarges it. In this and in other respects certain insects seem to take the step of reason that quadrupeds are incapable of.
Lloyd Morgan relates at some length the experiments he tried with his fox-terrier, Tony, trying to teach him how to bring a stick through a fence with vertical palings. The spaces would allow the dog to pass through, but the palings caught the ends of the stick which the dog carried in his mouth. When his master encouraged him he pushed and struggled vigorously. Not succeeding, he went back, lay down, and began gnawing the stick. Then he tried again, and stuck as before, but by a chance movement of his head to one side finally got the stick through. His master patted him approvingly and sent him for the stick again. Again he seized it by the middle, and of course brought up against the palings. After some struggles he dropped it and came through without it. Then, encouraged by his master, he put his head through, seized the stick, and tried to pull it through, dancing up and down in his endeavors. Time after time and day after day the experiment was repeated with practically the same results. The dog never mastered the problem. He could not see the relation of that stick to the opening in the fence. One time he worked and tugged three minutes trying to pull the stick through. Of course if he had had any mental conception of the problem or had thought about it at all, a single trial would have convinced him as well as a dozen trials. Mr. Morgan tried the experiment with other dogs with like result. When they did get the stick through it was always by chance.
It has never been necessary that the dog or his ancestors should know how to fetch long sticks through a narrow opening in a fence. Hence he does not know the trick of it. But we have a little bird that knows the trick. The house-wren will carry a twig three inches long through a hole of half that diameter. She knows how to manage it because the wren tribe have handled twigs so long in building their nests that this knowledge has become a family instinct. What we call the intelligence of animals is limited for the most part to sense perception and sense memory. We teach them certain things, train them to do tricks quite beyond the range of their natural intelligence, not because we enlighten their minds or develop their reason, but mainly by the force of habit. Through repetition the act becomes automatic. Who ever saw a trained animal, unless it be the elephant, do anything that betrayed the least spark of conscious intelligence? The trained pig or the trained dog or the trained lion does its "stunt" precisely as a machine would do it—without any more appreciation of what it is doing. The trainer and public performer find that things must always be done in the same fixed order; any change, anything unusual, any strange sound, light, color, or movement, and trouble at once ensues.
I read of a beaver that cut down a tree which stood or was held in such a way that it did not fall, but simply dropped down the height of the stump. The beaver cut it off again; again it dropped and refused to fall; he cut it off a third and a fourth time; still the tree stood. Then he gave it up. Now, so far as I can see, the only intelligence the animal showed was when it ceased to cut off the tree. Had it been a complete automaton, it would have gone on cutting—would it not?—till it made stove-wood of the whole tree. It was confronted by a new problem, but after a while it took the hint. Of course it did not understand what was the matter, as you and I would have done, but it evidently concluded that something was wrong. Was this of itself an act of intelligence? Though it may be that its ceasing to cut off the tree was simply the result of discouragement, and involved no mental conclusion at all. It is a new problem, a new condition, that tests an animal's intelligence. How long it takes a caged bird or a beast to learn that it cannot escape! What a man would see at a glance it takes weeks or months to pound into the captive bird or squirrel or coon. When the prisoner ceases to struggle, it is probably not because it has at last come to understand the situation, but because it is discouraged. It is checked, but not enlightened.
Even so careful an observer as Gilbert White credits the swallow with an act of
