ties of the first order.

As an example of flight arranged with intelligence, we have already
seen how the _Formica fusca_ profits by the difficulty experienced by
the _Polyergus_ in climbing. It hastily gains the summit of a blade of
grass, to place there in safety the larvae which the others wish to
carry away. The ruses adopted in flight are as varied as those of
attack. Every animal tries to profit as much as possible by all his
resources.

Larks, a feeble race of birds, rise higher in the air than any
rapacious bird, and this is often a cause of safety. Their greatest
enemy is the Hobby (_Hypotriorchis sublutes_). They fear him greatly,
so that as soon as one appears singing ceases, and each suddenly
closes his wings, falls to the earth and hides against the soil. But
some have mounted so high to pour out their clear song that they
cannot hope to reach the earth before being seized. Then, knowing that
the bird of prey is to be feared when he occupies a more elevated
position from which he can throw himself on them, they endeavour to
remain always above him. They mount higher and higher. The enemy seeks
to pass them, but they mount still, until at last the Hobby, heavier,
and little accustomed to this rarefied air, grows tired and gives up
the pursuit.[37]

[37] _Naturgeschichte der Voegel Deutschlands_, etc.

The Gold-winged Woodpecker of the United States (_Colaptes auratus_)
often escapes Falcons either by throwing himself into the first hole
that he finds, or if he cannot find one, through seizing the trunk of
a tree with his claws. As he is a very good climber, he describes
rapid spirals around it, and the falcon cannot in flying trace such
small circles. By this method the _Colaptes_ usually escapes.[38]

[38] Audubon, _Ornithological Biography_, New York and
Edinburgh, 1831-49.

The Fox, who is so ingenious in hunting, is not less so when his own
safety is concerned. He knows when it is best to flee or to remain; he
is suspicious in a surprising degree, not only of man but also of the
engines which man prepares against him. He recognises them or smells
them. Certain facts almost lead us to suspect that he understands
their mechanism. When one of them has been surprised in his hole, and
the trap has been placed before every opening, he will not emerge from
the burrow. If hunger becomes too imperious, he recognises that
patience will only change the manner of his death, and then he decides