I read of a beaver that cut down a tree which 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 independent 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, and after a while it took the hint. Of course it did not understand what was the matter, as you and I would have, 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 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 judgment to which it is not entitled. He says that in order that the mud nest may not advance too rapidly and so fall of its own weight, the bird works at it only in the morning, and plays and feeds the rest of the day, thus giving the mud a chance to harden. Had not the genial parson observed that this is the practice of all birds during nest-building—that they work in the early morning hours and feed and amuse themselves the rest of the day? In the case of the mud-builders, this interim of course gives the mud a chance to harden, but are we justified in crediting them with this forethought?
Such skill and intelligence as a bird seems to display in the building of its nest, and yet at times such stupidity! I have known a phœbe-bird to start four nests at once, and work more or less upon all of them. She had deserted the ancestral sites under the shelving rocks and come to a new porch, upon the plate of which she started her four nests. She blundered because her race had had little or no experience with porches. There were four or more places upon the plate just alike, and whichever one of these she chanced to strike with her loaded beak she regarded as the right one. Her instinct served her up to a certain point, but it did not enable her to discriminate between those rafters. Where a little original intelligence should have come into play she was deficient. Her progenitors Had built under rocks where there was little chance for mistakes of this sort, and they had learned through ages of experience to blend the nest with its surroundings, by the use of moss, the better to conceal it. My phœbe brought her moss to the new timbers of the porch, where it had precisely the opposite effect to what it had under the gray mossy rocks.
I was amused at the case of a robin that recently came to my knowledge. The bird built its nest in the south end of a rude shed that covered a table at a railroad terminus upon which a locomotive was frequently turned. When her end of the shed was turned to the north she built another nest in the temporary south end, and as the reversal of the shed ends continued from day to day, she soon had two nests with two sets of eggs. When I last heard from her, she was consistently sitting on that particular nest which happened to be for the time being in the end of the shed facing toward the south. The bewildered bird evidently had had no experience with the tricks of turn-tables!
An intelligent man once told me that crabs could reason, and this was his proof: In hunting for crabs in shallow water, he found one that had just cast its shell, but the crab put up just as brave a fight as ever, though of course it was powerless to inflict any pain; as soon as the creature found that its bluff game did not work, it offered no further resistance. Now I should as soon say a wasp reasoned because a stingless drone, or male, when you capture him, will make all the motions with its body, curving and thrusting, that its sting-equipped fellows do. This action is from an inherited instinct, and is purely automatic. The wasp is not putting up a bluff game; it is really trying to sting you, but has not the weapon. The shell-less crab quickly reacts at your approach, as is its nature to do, and then quickly ceases its defense because in its enfeebled condition the impulse of defense is feeble also. Its surrender was on physiological, not upon rational grounds.
Thus do we without thinking impute the higher faculties to even the lowest forms of animal life. Much in our own lives is purely automatic—the quick reaction to appropriate stimuli, as when we ward off a blow, or dodge a missile, or make ourselves agreeable to the opposite sex; and much also is inherited or unconsciously imitative.
Because man, then, is half animal, shall we say that the animal is half man? This seems to be the logic of some people. The animal man, while retaining much of his animality, has evolved from it higher faculties and attributes, while our four-footed kindred have not thus progressed.
Man is undoubtedly of animal origin, but his rise occurred when the principle of variation was much more active, when the forms and forces of nature were much more youthful and plastic, when the seething and fermenting of the vital fluids were at a high pitch in the far past, and it was high tide with the creative impulse. The world is aging, and, no doubt, the power of initiative in Nature is becoming less and less. I think it safe to say that the worm no longer aspires to be man.