Wood County reporter. [volume] (Grand Rapids [i.e. Wisconsin Rapids], Wis.) 1857-1923, 1883-11-15
Artificial S3a-Bot -01s and tha Chameleon
PloundaT,

FlouadaT.
In describing "Pr0feS<or Agassiz' S
Laboratory" 1T Newport. Ernest niger
soil says in the Century: The tables
are not of large size.-about like q IL
brary desk, but are firmly constructed
and seryiceable. They are covered with
English glazed tiles, - white. except
two black rows at the end, furnishing
opposite backgrounds to the glass yes
sci in which the often almost invisible
mOrsel of animal life is floating. What
cannot readily be seen against q white
surface may become plainly apparent
IN front of a black one. On the long
middle table thereafter describedH Mr..
Agassiz has enlarged upon this idea by
covering them with spaces of variously
colOred tiles Stimulating natural sea-
bottoms. The clear gray does we'll
enough for sand; dark leaden gray for
mud; notified CASTLE soap pattern in
brown for pebbles; and dulse-green for
sea-Weed. 1t is q popular error, or, at
any rate, prevalent thoughtlessness,
that sea animals pay no attention to the
sort Of bottom underneath them as they
move about Ii this is true of any, it
certainly is not Of q large number of
kinds. Some are confined to districts
limited by one sort Of bottom because it
provides their only food; others because
they are safer from harm than they
would be elsewhere; q third class per-
haps from choice, or from some reason
not readily discernable. In any case,
it has been both suspected and proved
that the character of the bottom has
great influence, particularly in the
matter Of color, upon the fishes and
others frequenting q district of mud or
sand or rocky or weed-grown bottom
respectively. 1t was in order to ex-
pertinent in this direction that Mr..
Agassiz invented and provided these
initiative surfaces, which should form
an artificial bottom resembling sand,
pebbles. etc., when the dish contain
inc fish or invertebrate to be deceived
should be set upon it.
Il can mention here only one of the
interesting results of the experiments.
The founder, as everybody knows, is
an Unlocking, dark-cOiOred, fiat fish,
which creeps close along the bottom,
and frequents for the most part banks
of mud, from which it is almost indis-
tinguishable. Occasionally the founder
occurs in sandy districts, in which case
it is of yellowish tinge, though not
otherwise different from its black neigh
Dor of the mud. Taking young fioun-
ders, Mr.. Agassiz experimental upon
the power OF changing color. Placing
them upon the bIackish tiles, they
quickly turned mud-color; moved thence
to the sand tiles. only Il few moments
elapsed before their Ieaden skins had
paled to dull yellowish white; trans
ferred to the mimic 'sea-weed, in less
than five minutes a greenish hue over
spread their skins, which would have
served we'll in their native element to
keep them unobserVed against a mass
of alga As the founders grew older,
the~ rapidity and facility with which
these changes were effected lessened,
and perhaps they would altogether
cease in aged individuals who had new
er practiced as turn-coats; but the
readiness with which the youngsters al
tered their compilations to suit their
circumstances, as shown by expert
ments in this laboratory, would give
them high rank in partisan politics.