t night the
Crow is without defence against the ravisher, for whom, on the
contrary, obscurity is propitious. Thus they recognise him as a
hereditary enemy, and never allow an opportunity of revenge to pass
without profiting by it. If by chance an owl appears by day and one of
them perceives him, immediately a clamour arises--a veritable cry of
war; all those who are in the neighbourhood fly to the spot, and
business ceases; the nocturnal bird of prey is assaulted, riddled with
blows from beaks, stunned, his feathers torn out, and, notwithstanding
his defence, he succumbs to numbers.

In all the preceding examples the social species unite for the common
security the forces and effects which they can derive from their own
organs.

I have spoken of the Apes and described how they defend themselves
with their hands and teeth; but in certain cases they use weapons,
employing foreign objects like a club or like projectiles.

Acts of this nature are considered to indicate a high degree of
development, and it has often been repeated that they are the appanage
of man alone; we have, however, seen the _Toxotes_, who, like all
fishes, is not particularly intelligent, squirt water on to his
victims. It is not easy to understand how a greater intellectual
effort is required to throw a stone with the hand than to project
water with the mouth. This is what the apes do, throwing on their
assailants from the heights of trees everything which comes to hand:
cocoa-nuts, hard fruits, fragments of wood, etc.

Baboons (_Cynocephali_) who usually live in the midst of rocks protect
their retreat by rolling very heavy blocks on to their aggressors, or
by forcibly throwing stones about the size of the fist. As these bands
may contain from a hundred to one hundred and fifty individuals, it is
a veritable hail of stones of all sizes which they roll down from the
heights of the mountains where they find shelter.

_Sentinels._--Not only do Apes know how to face danger or to avoid it
by a prudent flight, but they also seek to foresee it, and to avoid
exposing themselves to it. A troop of Apes, according to Brehm,
generally places the leadership in the hands of a robust and
experienced male. This primitive royalty is founded partly on the
confidence inspired by an old chief, and partly by the fear inspired
by his muscular arms and ferocious canine teeth. (Fig. 9.) He gives
himself a great deal of trouble for the security of his subjects, and
d