directs the act by conforming it to the needs of the accidental.
Within these limits, are animals capable of reasoning? Are they able
to connect a 'because' with a 'why' and afterwards to regulate their
behaviour accordingly? Are they able to change their line of conduct
when faced with an emergency?

History has but few data likely to be of use to us here; and those
which we find scattered in various authors are seldom able to
withstand a severe examination. One of the most remarkable of which I
know is supplied by Erasmus Darwin, in his book entitled "Zoonomia."
It tells of a Wasp that has just caught and killed a big Fly. The wind
is blowing; and the huntress, hampered in her flight by the great area
presented by her prize, alights on the ground to amputate the abdomen,
the head and the wings; she flies away, carrying with her only the
thorax, which gives less hold to the wind. If we keep to the bald
facts, this does, I admit, give a semblance of reason. The Wasp
appears to grasp the relation between cause and effect. The effect is
the resistance experienced in the flight; the cause is the dimensions
of the prey contending with the air. Hence the logical conclusion:
those dimensions must be lessened; the abdomen, the head and, above
all, the wings must be chopped off; and the resistance will be
decreased. (I would gladly, if I were able, cancel some rather hasty
lines which I allowed myself to pen in the first volume of these
"Souvenirs" but scripta manent. All that I can do is to make amends
now, in this note, for the error into which I fell. Relying on
Lacordaire, who quotes this instance from Erasmus Darwin in his own
"Introduction a l'entomologie", I believed that a Sphex was given as
the heroine of the story. How could I do otherwise, not having the
original text in front of me? How could I suspect that an entomologist
of Lacordaire's standing should be capable of such a blunder as to