Page:Popular Science Monthly Volume 77.djvu/128

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N earlier papers we have tried to show how the behavior of wild birds is moulded upon instinct and how some of their instincts have been modified on a large scale, or specialized in a peculiar manner. We shall now examine the other side of the shield, in order to ascertain how intelligently they work, and in relation to their intelligence it will be necessary to consider the growth of the young, and the development of certain instincts, more particularly that of fear.

Many birds, like some mammals, have been lauded by idealists, as paragons of virtue, and endowed with all the human or even angelic powers of intelligence and reason; others, again, have regarded them as the slaves of a blind or stupid instinct, whose lives are stereotyped, and run in grooves, determined largely by heredity. "Do not speak of blind instinct," says Michelet, the historian, "facts demonstrate how that clear-sighted instinct modifies itself according to surrounding conditions; in other words, how that rudimentary reason differs in its nature from the lofty human reason." "Through the thick calcareous shell, where your rude hand perceives nothing," the bird-mother "feels by a delicate tact the mysterious being which she nourishes and forms. . . . She sees it delicate and charming in its soft down of infancy, and she predicts with the vision of hope that it will be vigorous and bold, when, with outspread wings, it shall eye the sun and breast the storm."

While we are not over-zealous in applying the rule of parsimony, like most modern students, we are compelled to take-a middle course. When the degrees of intelligence can be more justly weighed, the mental powers of birds, as well as of mammals, will be better understood. At present the balance does not seen to swing very far on the side of intelligence. It is certain that the instincts of birds are modified at every step by association, and that the automatism of habit is quite as striking as that due to heredity, which it sometimes replaces. Many birds learn readily from experience; some remember long, when past experience serves as guide to future conduct. It may well be doubted if they ever attain to the level of analogical reasoning, or of deliberately inventing the means in order to attain a definite aim.

Every observer is no doubt unduly influenced by the force of