Wood County reporter. [volume] (Grand Rapids [i.e. Wisconsin Rapids], Wis.) 1857-1923, 1902-05-08
SEEN IN BRUTE EYES.
What an Examination of the Optics
of Wild Animals Shows

of Wild Animals Shows.
One Of the most remarkable scien
tific Investigations of modern times i:
now being brought by Dr. Lindsay
Johnson, F. R. c. s., to the close of it:
earlier stages.
It is some years ago now since the
doctor, bordering over certain appear
iGnces-called the ''fundus ocuIi'-at
the back Of the human eye, began tc
wonder whether monkeys possessed
the peculiar spot in the center of Wis
ion known as the 'macula lutea." OF
yellow spot-the part of the eye in
man which is used in reading.
He betook himself to Jamrach-s col.
/ lection of animals, and other
menageries, and found with as
! constituent that all the mon.
| keys did possess that spot as
in man, but that it varied with each
genus. Following up this clew. he
! discovered that every family of the
] mammalian order possessed a distinct
/ appearance of its own in the eye. by
which anyone seeing the back OF the
eye with an opthalmoscope and a light
would be able to recognize not only
| the family, but the genus of the
animal.
He then proceeded Systematically to
examine all the animals to be seen in
the geological gardens of London. Ant
werp, Amsterdam, Hamburg and else
where; and as a result Of this gigantic
labor he found many new and striking
facts For instance, he realized that
certain organs, such as the pecteh,
which sticks out from the optic nerve
inside the eye of all birds without ex-
ception, and of certain reptiles, was
also to be found in a large number of
the lower animals-rodents and mars
upials. This of itself was an interest
ing piece of evidence in support of
the Darwinian doctrine of evolution;
but the doctors various discoveries
are to be found recorded in the pro-
ceedings of the Royal society
His method of investigating. how
ever, has not been vet recorded. and
this to the general public will be the
more interesting portion of the story
of his work. To examine the eyes of
the animals it was necessary for DR..
Johnson to darken the cage, to sit be,
side the animal with a lamp behind
his head, and to look through the OBJ
kaleidoscope at distance of half an
inch from the animals eye, for period
Of not less than two hours at time.
The total time spent over each
animal would vorv frO,, oirb+ IN civ
teen hours. He examined the eyes of
about a thousand animals, and made
drawings of about two hundred and
fifty, some fifty of which have so far
been published by the Royal Society.
In the cases of the larger animals it
was, of course, necessary to confine
their movements. Thus the elephants
were chained down. Sacks some eight
feet long were made for slipping over
the bears, which were then confined
in them with ropes The closed ends
of the sacks were next slit with a
knife, and as Bruin produced his head
he was promptly muzzled and lifted on
to the table for tAe eye-testing.
In the cases of lions, leopards, tigers
and large cats muZZles could not be
used as they frightened the animals
nearly to death; and the doctor had
therefore to resort to private menag-
cries, where the beasts were less wild
Here he found it advisable to cut
off the whiskers of the brutes, as the
touching Of the whiskers during the
examination made them snap.
The resourcefulness of the doctor
and his assistants had to be endless
Some of the birds were induced to
thrust their bills into large corks, and
the fishes had to be treated very