On the Origin of Species HTML version

Instincts comparable with habits, but different in their origin -- Instincts graduated --
Aphides and ants -- Instincts variable -- Domestic instincts, their origin -- Natural
instincts of the cuckoo, molothrus, ostrich, and parasitic bees -- Slave-making ants --
Hive-bee, its cell-making instinct -- Changes of instinct and structure not necessarily
simultaneous -- Difficulties of the theory of the Natural Selection of instincts -- Neuter or
sterile insects -- Summary.
Many instincts are so wonderful that their development will probably appear to the reader
a difficulty sufficient to overthrow my whole theory. I may here premise, that I have
nothing to do with the origin of the mental powers, any more than I have with that of life
itself. We are concerned only with the diversities of instinct and of the other mental
faculties in animals of the same class.
I will not attempt any definition of instinct. It would be easy to show that several distinct
mental actions are commonly embraced by this term; but every one understands what is
meant, when it is said that instinct impels the cuckoo to migrate and to lay her eggs in
other birds' nests. An action, which we ourselves require experience to enable us to
perform, when performed by an animal, more especially by a very young one, without
experience, and when performed by many individuals in the same way, without their
knowing for what purpose it is performed, is usually said to be instinctive. But I could
show that none of these characters are universal. A little dose of judgment or reason, as
Pierre Huber expresses it, often comes into play, even with animals low in the scale of
Frederick Cuvier and several of the older metaphysicians have compared instinct with
habit. This comparison gives, I think, an accurate notion of the frame of mind under
which an instinctive action is performed, but not necessarily of its origin. How
unconsciously many habitual actions are performed, indeed not rarely in direct opposition
to our conscious will! yet they may be modified by the will or reason. Habits easily
become associated with other habits, with certain periods of time and states of the body.
When once acquired, they often remain constant throughout life. Several other points of
resemblance between instincts and habits could be pointed out. As in repeating a well-
known song, so in instincts, one action follows another by a sort of rhythm; if a person be
interrupted in a song, or in repeating anything by rote, he is generally forced to go back to
recover the habitual train of thought: so P. Huber found it was with a caterpillar, which
makes a very complicated hammock; for if he took a caterpillar which had completed its
hammock up to, say, the sixth stage of construction, and put it into a hammock completed
up only to the third stage, the caterpillar simply re-performed the fourth, fifth, and sixth
stages of construction. If, however, a caterpillar were taken out of a hammock made up,
for instance, to the third stage, and were put into one finished up to the sixth stage, so that
much of its work was already done for it, far from deriving any benefit from this, it was
much embarrassed, and, in order to complete its hammock, seemed forced to start from
the third stage, where it had left off, and thus tried to complete the already finished work.