death, or of self,
or of preservation. He has probably attained to no one of these
conceptions in such a way as to react definitely upon it. He acts in
each case separately, and simply because he cannot help it; being so
framed that when that particular running thing called a mouse appears in
his field of vision he _must_ pursue; that when that particular barking
and obstreperous thing called a dog appears he _must_ retire, if at a
distance, and scratch if close by; that he _must_ withdraw his feet from
water and his face from flame, etc. His nervous system is to a great
extent a pre-organized bundle of such reactions. They are as fatal as
sneezing, and exactly correlated to their special excitants as it to its
own."[6]

You ask, Why does the lark rise on the flash of a sunbeam from his
meadow to the morning sky, leaving a trail of melody to mark his flight?
Why does the beaver build his dam, and the oriole hang her nest? Why are
myriads of animal forms on the earth today doing what they were
countless generations ago? Why does the lover seek the maid, and the
mother cherish her young? _Because the voice of the past speaks to the
present, and the present has no choice but to obey._

INSTINCTS ARE RACIAL HABITS.--Instincts are the habits of the race which
it bequeaths to the individual; the individual takes these for his
start, and then modifies them through education, and thus adapts himself
to his environment. Through his instincts, the individual is enabled to
short-cut racial experience, and begin at once on life activities which
the race has been ages in acquiring. Instinct preserves to us what the
race has achieved in experience, and so starts us out where the race
left off.

UNMODIFIED INSTINCT IS BLIND.--Many of the lower animal forms act on
instinct blindly, unable to use past experience to guide their acts,
incapable of education. Some of them carry out seemingly marvelous
activities, yet their acts are as automatic as those of a machine and as
devoid of foresight. A species of mud wasp carefully selects clay of
just the right consistency, finds a somewhat sheltered nook under the
eaves, and builds its nest, leaving one open door. Then it seeks a
certain kind of spider, and having stung it so as to benumb without
killing, carries it into the new-made nest, lays its eggs on the body of
the spider so that the young wasps may have food immediately upon
hatching out, then goes out and plasters the door over care