f but two animals, the
man-like ape and the elephant, that used anything like a tool or
weapon to attain their ends. How could the crow gain the knowledge or
the experience which this trick implies? What could induce it to make
the first experiment of breaking an egg with a falling stone but an
acquaintance with physical laws such as man alone possesses? The first
step in this chain of causation it is easy to conceive of any animal
taking; namely, the direct application of its own powers or weapons to
the breaking of the shell. But the second step,--the making use of a
foreign substance or object in the way described,--that is what
staggers one.

Our own crow has great cunning, but it is only cunning. He is
suspicious of everything that looks like design, that suggests a trap,
even a harmless string stretched around a corn-field. As a natural
philosopher he makes a poor show, and the egg or the shell that he
cannot open with his own beak he leaves behind. Yet even his alleged
method of dropping clams upon the rocks to break the shells does not
seem incredible. He might easily drop a clam by accident, and then,
finding the shell broken, repeat the experiment. He is still only
taking the first step in the sequence of causations.

A recent English nature-writer, on the whole, I think, a good observer
and truthful reporter, Mr. Richard Kearton, tells of an osprey that
did this incredible thing: to prevent its eggs from being harmed by an
enforced exposure to the sun, the bird plunged into the lake, then
rose, and shook its dripping plumage over the nest. The writer
apparently reports this story at second-hand. It is incredible to me,
because it implies a knowledge that the hawk could not possibly
possess.

Such an emergency could hardly arise once in a lifetime to it or its
forbears. Hence the act could not have been the result of inherited
habit, or instinct, and as an original act on the part of the osprey
it is not credible. The bird probably plunged into the lake for a
fish, and then by accident shook itself above the eggs. In any case,
the amount of water that would fall upon the eggs under such
circumstances would be too slight to temper appreciably the heat.

There is little doubt that among certain of our common birds the male,
during periods of excessive heat, has been known to shade the female
with his outstretched wings, and the mother bird to shade her young in
the same way. But this is a different matter.