er, and
may escape death by plunging. The eagle knows this advantage, so he
compels the swan to remain in the air by attacking him from below and
repeatedly striking his belly. Weakened by the flow of blood, and
obliged to fly, not being able to reach the water without finding the
sharp beak which strikes him, the swan succumbs in this unequal
combat, which has been vividly described by Audubon.

[Illustration: FIG. 4.]

The bird who displays the most remarkable qualities in this struggle
which terminates the chase, exhibiting indeed a real fencing match, is
the Secretary Bird (_Gypogeranus reptilivorus_. Fig. 4.) He is the
more interested in striking without being himself struck since the
fangs with which his prey, the snake, is generally armed might at the
first blow give him a mortal wound. In South Africa he pursues every
snake, even the most venomous. Warned by instinct of the terrible
enemy he has met, the reptile at first seeks safety in flight; the
Secretary follows him on foot, and the ardour of the chase does not
prevent him from being constantly on guard. This is because the snake,
finding himself nearly overtaken, suddenly turns round, ready to use
his defensive weapons. The bird stops, and turns in one of his wings
to protect the lower parts of his body. A real duel then begins. The
snake throws himself on his enemy, who at each stroke parries with the
end of his wing; the fangs are buried in the great feathers which
terminate it, and there leave their poison without producing any
effect. All this time with the other wing the Secretary repeatedly
strikes the reptile, who is at last stunned, and rolls over on the
earth. The conqueror rapidly thrusts his beak into his skull, throws
his victim into the air, and swallows him.[20]

[20] The combat was minutely described by Le Vaillant
(_Hist. Nat. des Oiseaux d'Afrique_, Paris, 1798, t. i. p.
177), whose account has been confirmed by many subsequent
observers.

[Illustration: FIG. 5.]

_Hunting with projectiles._--It has often been repeated that Man is
the only creature sufficiently intelligent to utilise as weapons
exterior objects like a stone or a stick; in a much greater degree,
therefore, it was said, was he the only creature capable of striking
from afar with a projectile. Nevertheless creatures so inferior as
fish exhibit extreme skill in the art of reaching their prey at a
distance. Several act in this way. There is firs