The New York herald., 1922-10-01


| when animals move away from situa-
tions which are unfavorabie TO the ex-
ercise OF their normal tropsms.
The sudden change provokes an oppo-
site kind OF activity which lasts for a
time. after which there is a return to
the former state or direction, and an i'm
portant fact is that the sudden change,
say a gust OF wind. a warm breath or
altering the slope Of the surface on
which the insect creeps, may reverse the
creatures behavior i'm regard to some
quite different kind OF stimulation such
| as light
| a well known expression Of differen-
tial sensitiveness is seen in cases OF So
called death feigning. The reaction to
tho sudden change is abrupt immobiliza-
tion. Many a beetle suddenly seized
becomes instantaneously rigid and may
remain In this condition though no
longer molested for half an hour. In
some cases the muscles pass into n tet-
anic state so that big insect like a
water bug can be held out stiffiy by one
Of its slender legs. In higher animals
the catalepsy may sometimes have pro-
tective value. but among insects it rarely
admits Of any unitarian Interpretation.
1t appears to be an exaggeration of diff
ferential senstlveness
SO far, then, in tropisms, vital rhythms
and dfferential sensitiveness there is
little indication OF any pental aspect
or that the first clear evidence is to be
looked for when the creature tries one
reaction after another and selects that
which is most satisfactory--the trial and
error method---or when it illustrates
learning. which involves individual as
sociative memory.
A wasp struggles ingeniously to get
it's booty over obstacles; mortar bee
searches for the shifted snail shell in
which It has laid Is eggs. and having
found where we have put It remembers
the place; a cockroach can be taught by
electric shocks to avoid a dark passage
in its cage; the sacred scarab that makes
balls of dung alters it's behavior accord
ing to the nature OF the soit; the solitary
urn making wasp Ammophila closes it's
nest perfunctorily so long as it is not
fully provisioned. but when the labor of
collecting food for the future larvae is
over there is careful blocking of the
door and smoothing of the surface. In
some cases a little pebble is used as a
pounding instrument. Here we see indi-
yiduality, alternatives, some apprecia-
tion of means and ends.
The next level Of behavior is instinc-
tive. 1t includes the innate and auto
matte capacities Of the creature as a
whole. chain Of doings which are indi-
vidually like refexes. but have a psychic
as well as a physiological concateuation
-"automatisms dominated by cerebral
activity" Instructive behavior tends to
routine and yet It Is often variable: it is
not the result OF lapsed intelligence and
yet it tends to become more and more
automatic.
According to Bouvier one can hardly
some mechanists have called them, "for
they know how to bend to circumstances.
20 acquire new habits. to learn and to
retain. to show discernment. They are,
one can say somnambulsts whose minds
awaken and give proof OF intelligence
when there is need for it." But when
the instructive behavior is most perfect
and seems almost rational it Is probably
most divergent from intelligence.
Never are the insects so far from us
as when they appear to resemble US
most"
Let US complete our ascent of the in
cined plane of insect behavior by citing
case where we shobhd say that intelli-
gence takes the reins. There are preda-
tory wasps called 'pompilids that hunt
spiders and are very diverse In their be-
havior. There Is one kind that follows a
trap door spider down her shaft and
stings her there. But in the autumn
this spider makes a side shaft with a
separate door on the surface of the soil
and this makes capture more difficult.
What does Pompilus do? One trick
is to carry away the two doors for this
induces the spider to come up to repair
the damage. Another trick is to stick
the tail into one of the doors and then
withdraw quickly to watch the other.
IL nothing happens the wasp does the
same thing at the other door. A third
trick is to give certain knocks at one OF
the doors, at the same time watching the
other. The spider eventually jumps out,
a, creature of great agility. but the wasp
is quicker still. 1t does not seem too
generous to call this kind of behavior
intelligent.