Rock Island daily Argus. (Rock Island, Ill.) 1886-1893, 1888-12-06
AN APE COUNTS FIVE.
SUCCESS IN TEACHING MATHEMAT.
les TO A CHlMPANzEE.

The Method Adopted by the Experimental,
A Psychological Distinction-How Ami
mails Count - Estimating by Muscular
sense-A Problem for Scientists.
About year ago began, with the assist
ance OF the keeper, to instruct the chimpan-
zee at the Geological gardens in the art of
computation. The method adopted was to
ask her for one, two, three, four or five
straws, which She was to pick up and hand
out from among the litter In her cage. OF
course, no constant order was observed in
making these requests, but whenever she
handed number not asked for her offer was
refused. In this way the animal learned to
associate the numbers with their names
tAastly, II more than one straw were asked
LOT, sne was taught 10 hold the others in her
mouth until the required number was com
plete, and then to deliver the whole at once.
Ihis method prevented any possible error
arising from her Interpretation of vocal
tones-an error which might we'll have
arisen If each straw had been asked for sep
arately
RARELY MADE A MISTAKE.
After few weeks continuous instruction
the ape perfectly well understood what was
required of her, and up to the time when
left town, several months ago, she rarely
made mistake in handing me the exact
number of straws that named. Doubtless
she still continued to do so for her keeper
For Instance, if she is asked for four straws
she successfully picks up three and puts them
IN ner mouth; then she picks up fourth and
nanos over all the four together Thus there
can De no doubt that the animal is clearly
aole to distinguish between the numbers l. Q.
o, and 8, and that she understands the name
Tor each. But as this chimpanzee is somewhat
capricious in her moods, even private visitors
must not be disappointed if they fail to be
entertained by an exhibition of her learning
"a caution which it seems desirable to add
as this is the first time that the attainmsnts
OF my pupil have been made known to the
public, although they have been witnessed
oy Officers OF the society and other biological
friends
nave sent these fgcts to you, sir, because
thlnk That they bear out the psychological
distinction between sensuous estimation and
intellectual notation ANY child, year after.
emerging from infancy and not yet knowing
Its numerals, could Immediately see the
difference between five pigs and six pigs and
therefore, as your writer indicates it would
be an extraordinary fact if a savage were
unable to do so. But if the savage had to deal
with larger number M pigs the insufficiency
OF his sensuous estimation would increase
WITH the increase of numbers until a poipt
would be reached at which, if be were 10
keep count at all, he would be Obliged to re-
sort to some system of notation-tnat is TO
mark Off each separate unit with separate
nota, whether by fingers notches or words,
HOW ANIMALS COUNT.
Thus there is counting and countinr-dis-
tingulshing between low numbers by directly
approaching the difference between two
Quantities Of sensuous perceptions, and dis
tlngulshlng between numbers OF any amount
by marking each sensuous perception with a
separate sign. OF course, in the above in
stances OF animals counting, it must be the
former method alone that is EMPLOYED. and
therefore | have not sought to carry the ape
beyond the number five, lest | should spoil
the results already gained But a careful
research has been made 10 find how far this
method can be carried in the case Of man
The experiments consisted in ascertaininp
the number Of objects such as dots on a
piece OF paper which admit of being stimuli
taneously estimated with accuracy. 1t was
found that the number admits of being
largely increased by practice, until, with an
exposure to view Of one seconds duration.
the estimate admits of being correctly made
up to between twentyeand thirty objects.
In the case OF the ape it is astonishing over
how long time the estimate endures. Snn-
posing, for instance, that she is requested to
find five colored straws. She perfectly well
understands what is wanted, but as colored
straws are rare in the litter she has to seek
about for them, and thus it takes har a lonp
time to complete the number; yet she re-
members how many she has successiyelv
found and put into her mouth, so that when
the number is completed she delivers il at
once After having consigned them to her
therefore, her estimate OF their number must
be formed either by the feelings of her
mouth or by retaining mental impression
OF the successive movements Of her arm in
picking up the straws and placing them in
her mouth. Without being able to decide
positively in which of these ways she Sti-
mates the number, am inclined to think it
Is in the latter. But, if So it is surprising,
as already remarked, over how long time
this estimate by muscular sense endures.-
Mr.. Rornaine in The London Times.