felt if the coughing movement is checked.
Sneezing, a protective reflex, is usually a slow reaction, giving time
for a conscious impulse to {109} sneeze before the reaction takes
place. The same is true of scratching and of swallowing, and of a
number of other reflexes. In short, it is impossible to draw a
satisfactory line between reflexes and instincts on the basis of
conscious impulse.

These cases point the way, however, to what is probably the best
distinction. It was when the flexion reflex was _delayed_ that it
began to look like an instinct, and it was because sneezing was a
_slow_ response that it had something of the character of an instinct.
Typically, a reflex is a prompt reaction. It occurs at once, on the
occurrence of its stimulus, and is done with. What is characteristic
of the instinct, on the contrary, is the persisting "tendency", set up
by a given stimulus, and directed towards a result which cannot be
instantly accomplished.

An Instinct Is a Native Reaction-Tendency

We would propose, then, to consider an instinct as an inner
adjustment, or tendency to reaction. It is this, rather than just a
reaction. When a stimulus promptly arouses a reaction, and that ends
the matter, we speak of reflex action--provided, of course, the
connection between stimulus and response is native. But when a
stimulus sets up a tendency to a reaction that cannot be immediately
executed, or towards an end-result which cannot immediately be
reached, and when the tendency so aroused persists for a time in
activity, and gives rise to preparatory reactions, then we speak of
instinct.

The "broody" hen makes a good picture of instinct. When in this
condition she responds to a nestful of eggs, as she does not at other
times, by sitting persistently on them and keeping them covered. She
is in a certain "organic state" that facilitates this response. In the
absence {110} of any nestful of eggs, she shows a peculiar restless
behavior that indicates to one who knows hens that this one "wants to
set." The tendency that has been awakened in her cannot be satisfied
by any momentary act, but persists and governs her actions for a
considerable period.

The nesting instinct of birds affords a still more complete example.
The end-result here, the finished nest, cannot be instantly had, and
the pair of birds keep on gathering materials and putting them
together until this end-result is present before their eyes. It is not
necessar