, 1877-08-26
INSTINCT AND INTELLIGENCE.

Science Monthly contains lecture from a
course on Theological Theories" delivered
at tho Johns Hopkins University, last jan
nary, by ". K. BEooKs, in which the quail
ties of instinct and intelligence are treated
from the standpoint of natural selection.
Th. lecture is too long to be printed entire,
but some Of the facts which it contains arc
too curious and important to be confined
strictly to magazine readers; therefore o
short summary Of them may not prove unin-
tcresting Sunday reading.
The lecturer seeks to show that, if "ani-
mails of given species are born with con-
stit1tional tendency OF instinct to perform a
certain action under certain circumstances,
this tendency may be improved and perfect
ed by natural selection, provided favorable
variations appear and be inherited and,
also, that ssif instinct varies in the different
individuals of @ species, the struggle for e1-
istcnce will result in the destruction Of those
in which it is imperfectly or ebnormally de-
yelopcd, and the preservation Of those which
exhibit any advantageous variation" Out Of
the wildnoss Of birds with regard to man, q
very ingenious argument is woven to show,
first, that this wi1dness is particular
instinct directed against man, nnd not the re-
suit OF caution produced by other sources Of
danger; and, second, that it is not acquired
by individual birds in short time, but be-
comes hereditary in the course of successive
generations. The old doctrine that instinct
differs from intelligence, inasmuch US it is IN
infal1ible guide and perfect in its results, is
not only exploded BY the fact that it is capn-
bic of improvement, but also by the more
curious fact that it often fails rs guide.
As illustrations of this, migratory birds
often arrive too early and die for want Of
food. Insects which usually lay eggs upon
or near food, SO that their young may hive
subsistence, often mike mistake. Flies,
instead OF laying their eggs upon putrid
meat, have been known to lay them upon
vegetation which hns a similar odor, and
their young have persisted as soon as hatch
ed. The trap~door spider, which usually
builds its curious nest where there is yegeta-
ton which is necessity to it, have made
the snd, mistake of building in the sand, and
met tho fate Of the foolish man who did not
found his house upon the rock. In view Of
these and numerous other instances which
ara cited, Mr. DnooKs concludes that =" in
stinct is not fixed, immutoblo, perfect law
and guide, but an imperfect, improbable,
gradually acquired method of adjusting &C.
tions to the surrounding conditions, and,
therefore, subject to slow perfection through
the survival Of the fttest variations"
From tho investigation Of variations in in
stinct, Mr.. Brooks passes to the considera-
ton Of the question whether animals pos
sess other mental powers than the instinct
i've, or whether they exhibit any fncu1ty
which may properly be called intelligence.
Upon this point, he asserts that animals in
state of nature arc capnble of decided i'm
proyement. Old birds cannot be caught
with chatf. The inferior beaver houses are
invariably built by young and inexperienced
beavers. Young cats always mike failure
in bringing up their first itters in an excm-
plary manner, and the best and most com.
plcated nests are made by those birds whose
young remain longest in the nest. Dogs
dream, and under peculiar hardships or mis-
fortunes 60 crnzJ. ssDr. KANE tells us that
one of the Newfoundland dogs which spent
two Arctic winters with him was SO oppressed
by the darkness and solitude of the long
night, and 70 reduced in strength By hard
ship and cold, that it at last became insane,
and manifested all the symptoms which were
observed in some Of the human beings Of
the party who were affected in the same way
by the snu,s causes" Nearly all kinds Of
fowls have special cries for special
occasions, md the farmers dogs learn
to distinguish them. Even the insects mani
fest this intelligence, which is higher than
instinct. "When two armies of ants
of different species leave their homes Mt
the same time, arrange themselves in .ranks,
and march to point Of meeting md en-
gage IN battle, they exhibit, not simply
proofD Of concerted action, but evidences
that:they can arrange and plan to meet e1-
traordinary and unusual emergencies" The
Lecturer applies his theory even more closely
than this, and illustrates the actions of the
lowest organisms among animals, and even
plants, to show that some Of them are to be
placed above and some of them below in
stinct, the reflex or automatic actions in AMI
mails, and habitual actions which gre per-
formed unconsciously by man and animals.