CHAPTER II.

EXAMPLES OF INSTINCT IN THE WORKS OF ANIMALS, AND THE CARE OF THEIR YOUNG; AND IN THEIR CHOICE OF FOOD.-REMARKS ON THE ADAPTATION OF STRUCTURE TO CLIMATE, AND ADAPTATION OF HABIT AND DISPOSITION TO STRUCTURE, &c.

SECT. I.

Examples of Instinct in the Works of Animals, and the Care of their Young.

"THE works of animals, says Dr. Reid, present us with a wonderful variety of instincts; the nests of birds so similar in their situation and architecture in the same kind, so various in different kinds; the webs of spiders; the ball of the silk worm; the nests of ants and other mining animals; the combs of wasps, hornets, and bees; the dams and houses of beavers.

"But while every manufacturing art among men was invented by some man, improved by others, and brought to perfection by time and experience, and known only to those who have been taught them; in

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the arts of animals no individual can claim the invention. Every animal of the species has equal skill from the beginning, without teaching, without experience or habit. Every one has its art by a kind of inspiration; not that it is inspired with the principles or rules of the art, but with the ability and inclination of working in it to perfection, without any knowledge of its principles, rules, or end.

"The youngest pair of birds, it is known, without instruction or experience, build their first nest of the materials commonly used by their species; in situations too most secure and convenient for incubation and the rearing of their young."* This cannot be imitation; for, as Addison says, "Though you hatch a crow under a hen, and never let it see any of the works of its own kind, the nest it makes shall be the same, to the laying of a stick, with all the other nests of the same species. It cannot be reason: for were animals endued with it to as great a degree as man, their buildings would be as different as ours, according to the different conveniencies that they would propose to themselves." +

The work of every animal is, like the works of nature, perfect in its kind, and can bear the most critical examination of the mechanic or the mathematician. Let us take an example from the Bee. Dr. Reid further remarks, that "there are only three possible figures of the cells which can make them all + Spectator, vol. ii.

Reid's Essays, vol. iii. chap. 1.

equal and similar, without any useless interstices. These are the equilateral triangle, the square, and the regular hexagon. Mathematicians know that there is not a fourth way possible, in which a plane may be cut into little spaces that shall be equal, similar, and regular without useless spaces. Of the three figures, the hexagon is the most proper for conveniency and strength. Bees, as if they knew this, make their cells regular hexagons."

But the bottom of each cell rests upon the partitions between the cells on the other side, which serve as a buttress to strengthen it; and this gives it all the strength possible.

Again, it has been demonstrated that, by making the bottoms of the cells to consist of three planes meeting in a point, there is a saving of material and labour no way inconsiderable. The bees, as if acquainted with these principles of solid geometry, follow them most accurately. It is a curious mathematical problem, at what precise angle the three planes which compose the bottom of a cell ought to meet, in order to make the greatest possible saving, or the least expense, of material and labour. This is one of the problems which belong to the higher parts of mathematics. It has accordingly been resolved by some mathematicians, particularly by the ingenious Maclaurin, by a fluxionary calculation, which is to be found in the Transactions of the Royal Society of London. He has determined precisely the angle required, and he found by the most exact mensuration

the subject would admit, that it is the very angle in which the three planes in the bottom of the cell of a honey-comb do actually meet."

It has been therefore demonstrated, (as far as geometry and mathematics can show it,) that Bees build their cells in the strongest possible manner; and with the least possible expense of labour and materials. And hence it is proved, that on the supposition that they act with a view to consequences, they are more skilled in geometry and mathematics, than the most philosophical and learned men, and that too from the earliest ages. "We must therefore conclude that, although the Bees act geometrically, yet they understand neither the rules nor the principles of the arts which they practise so skilfully; and that the geometry is not in the Bee, but in the great Geometrician who made the Bee, and made all things in number, weight, and measure." *

Now when we see that animals, by Instinct, arrive at once to perfection in their art, while man is left to the exercise of his Reason, in other words, to his own skill and ingenuity, and very slowly attains to perfection, we must conclude that the former are guided by a more perfect wisdom than the latter, at least in these outward concerns of life.

In the second volume of the Spectator, Addison has taken a view somewhat similar, which illustrates not only the difference between Instinct and Reason, but the perfection of the former in its operations.

* See Reid's Essay, and Rees's Cyclopædia, art. Instinct.

He observes, "Animals in their generation are wiser" than the sons of men; but their wisdom is confined to a few particulars, and lies in a very narrow compass. Take a brute out of his instinct, and you find him wholly deprived of understanding. To use an instance that comes often under observation.

"With what caution does the hen provide herself a nest in places unfrequented, and free from noise and disturbance? When she has laid her eggs in such a manner as she can cover them, what care does she take in turning them frequently, that all parts may partake of the vital warmth? When she leaves them to provide for her necessary sustenance, how punctually does she return before they have time to cool and become incapable of producing an animal? In the summer you see her giving herself greater freedoms, and quitting her care for above two hours together; but in winter, when the rigour of the season would chill the principles of life, and destroy the young one, she grows more assiduous in her attendance, and stays away about half the time. When the birth approaches, with how much nicety and attention does she help the chick to break its prison? not to take notice of her covering it from the injuries of the weather, providing it proper nourishment, and teaching it to help itself; nor to mention her forsaking the nest, if, after the usual time of reckoning the young one does not make its appearance. A chemical operation could not be followed with greater art or diligence than is seen in the hatching of a