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Second Investigation.
About the little water bear.
Tab. IV. fig. 7.
It is fully justified to consider this being as one of the most rare
and most strange creatures. I call it rare because I have found it
only a few times in winter and not at all in summer.
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Furthermore I consider it as rare because I was unable to trace it
in the lists of the most famous scientists, whose eyes have seen much
more than mine. Even Mueller, this intelligent investigator,
apparently hasn'nt found it. o ) .
Strange is this little animal, because of its exceptional and strange morphology
and because it closely resembles a bear en miniature. That is the reason
why I decided to call it "little water bear". p ) .
But one shouldn't be afraid to watch those beasts of prey of the invisible world.
Nevertheless they are beasts of prey in relation to the other animalcules
of their worlds, similar to the tigers and the lions of the African deserts.
Nature has always put things into perspective to each other.
In this way our (big) world is organized. In the small world as well one animal
eats another animal because they are linked to each other in a chain.
Also among the infusoria are animals of various appeal. So it seems highly
probable that they are analogous not only in the visual appearance but
also as far as their other properties are concerned. Their behaviour proves
that also in the small world beasts of prey do exist. The voracity of some
species is as enormous as that of the real bears and
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the hyenas.
The tools and weapons of some of those infusoria are further proofs
of their carnivorous character. q ).
There is by sure no greater pleasure than to watch the polyps, the rotatoria
and the other beasts of prey under the microscope, how they get hold of
their victim and how they devour it.
All this is possible without travelling to distant countries, without
risking one's life and without enormous costs. A single lens is sufficient to
reveal a new world, and I know from own experience that one is
beside of oneself in amazement when seeing all this for
the first time. r ) .
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Perhaps I have been diverging a little bit too much. So I will return to my
bear. Everybody who will have seen it under a microscope
will attribute this name to the animal. The first time I have perceived
those worms on the 10th of December in 1772 on duckweed
over standing water. It is very strange that, what I would like to mention at
this point, during this month of December, when the chill has become
overwhelming elsewhere, the infusoria begin to increase in number.
Spallanzani has maintained for the insects that they mate in autumn.
s)
Because of this one will always find more and more various animalcules
in
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duckweed water during those winter months than at the hottest days
in summer. This fertility remains until spring when the old duckweed plants
die and the young ones substitute them.
I have noticed that the number of animalcules decreases at the moment when
the new duckweed plants come up and build their intermingling roots.
In contrast the number of animalcules is highest in
late autumn when the duckweed looses its roots and only the green
leaf of it floats on the water surface. When dipping one of those
leafs on a slide one will observe whole colonies of water animals
of various species which inhabitate this small insula.
An experience which I think is reproducible, as I have repeated this
experiment so often. In science often minute details turn out as
important. This has caused me to diverge. I will return to my investigation
of my little water bear now.
It is not possible to investigate the animal by means of the weaker
microscopic lenses. One will need stronger lenses in order
to perceive its shape and details.
Most of times I have used the second lens of my microscope. When I saw the
water bear for the first time I found it lying on its backside. I have found it
in this position later again and again. I was lucky to find it several
times.
Its body is not as transparent as those of other water animals. The skin
which covers the inner organs appears greyish and is covered by
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black grains (granulosum) so that it has the appearance of a scarred leather.
In the inner volume there is a completely non-transparent, oval black spot
oriented towards the upper part of the head.
The head itself t) is very short and thick and it has greatest resemblence
to a frog head, at least as far as the throat is concerned. On both sides
are eyes, slightly prominent, and clearly discernible.
The hind part of the body is roundish and there is neither a hair,
nor a tail which are also absent all over the body. On both sides there
are six to eight incisions which I consider as air tubes.
The most strange property of this little worm animal are eight short legs
each of which armed with three curved and very sharp claws u).
Its movements were always the same. It lay on its backside and stretched
its feet, retracted them as if it wanted to grip something with them in
order to come an upright position. But when it grasped a moss leaflet or
another particle it was nevertheless unable to stand up.
I have often tried to help with a fine needle; nevertheless it always
fell back on its backside. I flooded the droplet with the water bear on a
watch glass to see whether it was able to swim when it had more water
under its body but was not successful.
I have seen a funny spectacle which was a clear proof for me
that its claws perform not in the soft way,
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when it grips a living object. One of the oval animalcules which can be found
in any of the infusoria waters approached my water bear and was not very lucky
in that the water bear caught it with one of his legs.
The animal did an enormous jump, apparently sensing a severe hit. But the
bear didn't loosen its grip. Instead it took the smaller animal along a considerable
way along the droplet.
But it didn't try to grab at it stronger by means of its other legs either.
As the smaller animal was apparently caught in its claws it seemed not to care
about it, even when the smaller animal regained its freedom. The water bear remained in
its usual position and movement lying on its backside and continued to
jiggle around with its feet. I followed the freed animal and had the impression
that there was a crack on its backside and that it moved slower than before.
It moved towards the edge of the droplet and died there. From this I have
concluded that also the smallest animals have sensory feelings
and are able to feel pain. Their body seems to be different from
those polyps and other worms which even seem to take profit
from cuts and mutilations as they increase better under these conditions.
Creator of the elephants and atoms, of the whales and small living points
in water! I'am astonished by the endless variety of designs,
according to which your wisdom has formed in a different way the
body of each animal, the bird, the frog, the insect and the worm!
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By the way, I am unable to tell how my water bear reaches its prey
and what actually its food consists of. Its way of living doesn't appear
to be more than clinging to the duckweed as it cannot make use of its feet
for swimming. Whether its 24 claws are given to it by nature for
clinging to a substrate or for other purposes, I cannot tell yet.
But by sure you couldn't imagine a more horrible scenario than
to meet this animalcule in the size of a real bear.
I have dissected one of those animals by means of a fine needle.
The inner parts emerged as grains. Also the black spot mentioned above
came out, I think it must be some kind of ovary. The grains floated around
in the water and looked like transparent bubbles. I was not able to discern
further details from the interior parts.
At another time, I found in a droplet of duckweed water, which had been
standing for at least six weeks, some skins or shells of those
dead water bears ,v ) at which the claws of the eight legs were still visible.
Within one of those skins were eleven brown oval corpuscules, with
black spots, with the young animals included in them, some of which
were still moving, as myself and some of my friends noticed without
doubt, after having suspected a deception first. They looked very similar
to the habit and shape of the so-called volvox (globular) animals
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which are enclosed in a similar manner within their parent organisms. y )
At the end of this chapter I would like to
remark that this animal is not an object suited for the sun microscope.
It is not transparent enough to show sufficient detail.
The allmighty God said: Be it! as the earth,
this drop in a bucket, ran out of his hand. At this moment he condescended
to create also the small worm animal that has been discussed here, millions
of times smaller than a sand grain and kept it for 6,000 years. But for which reason
as I perhaps have been the first man to see it this year?
Lord! Who has been your advisor? He has created everything,
the sun, the clouds, the oceans, the depths, in the visible and
unvisible world, in the big wild animals and in the worm that hasn't be
seen by anybody. Let's honour him for eternity as I will honour him in my
heart!
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o At least I have not noticed it in his newest publication:
Vermium terrestrium et fluviatilium, seu animalium infusorium etc. succincta
historia Hafn. et Lipf. 1773.4.
p Cf. Cercaria catellus, lupus; Trichoda camelus, lepus;
Vorticella felis, catulus etc.
S. Müller, Vermium etc. hist. p. 65. 67. 108.
q I would like to remember here once that, in accordance with
Mr (Kanzleyrath, a German title) Müller I understand by the term
"infusoria" only those water worms which can be found in fresh water
and in water containing vegetable material. S. Vermium etc. succincta historia. p . 4.
Among the wild animals of the minute water world the wildest and most voracious
are those which can be found in cisterns the water of which has turned green,
in storm barrels, in troughs etc. and which I have described in issue 17
of the «Hannoverisches Magazin» in 1773.
They devour in a single swig myriads of other little animals.
Müller Vermium etc. historia p. 131. n 142, has named them Brachionus
urceolaris. Joblot (Observations d' histoire naturelle, faites avec le
Microscope etc. ā Paris 1754. 4. Tom. I. Part. II. Chap. XXX, p. 68. Pl. 9.)
calls them grenades aquatiques, coronnées et barbues.
r The thoughts of Mr (Kanzleyrath, a German title) Müller
about these topics are so impressive that I want to quote him word by word.
In the introduction to the publication already mentioned before (Infusoria ...).
Here are his words: p. 1. f.
Si quae de animalculis infusoria dici possunt, enar-
rentur, verbaque et oculorum acies sufficerent, dicendi
nullus finis esset. Paucissima magnificentiae et splen-
doris Numinis optimi maximi documenta prodere
mens humana valet, in plurimis stupet et obmutescit.
Mundus invisibilium maioribus occlusus, centum abhinc
annis, et quod excurrit, adiri coepit; monstra, forma et
vitae ratione, inaudita, alit, miraculisque aeque abun-
dat, ac remota Indiarum tellus, minori veri periculo
perlustratur, ubique enim ante pedes praesto est, nec
auri fame visitur. Utrumque multa incolarum strage
conquiritur; haec vero saepe vitae aggressorum dispen-
dio constitit, ille mera patientia comparatur. Aciculae
alterum, quae orbis terrarum hemisphaeria iunxit, al-
terum lenti, quae moleculas solares, moleculasque infuso-
rias, remotissima rerum, sub eandem imaginem sistit,
debetur. In hoc intervallo quid iam magnum, quid
arvum? Ens, quod hoc cogitat, et humana patitur.
s Bonnets Betrachtung über die Natur XI. Th. V. Hauptst.
p. 375.
t fig. 7. a, b, b.
u c, c, c, c.
v I do not want to call it a transformation, similar to the one of
the insects.
y This strange animal has its name from its globular shape. But it
can adopt numerous shapes, so that one might believe to see different
animals. Often it has 30 to 40 youngster animals in it, each of which
has again 6 to 8 in it from what might be concluded an enormous
fertility of a single adult, as it has already its child-child-child-child
in it. Their birth proceeds as follows: The skin of the adult
opens on one side. The youngsters emerge. But the mother which has given
birth, dies and looks like a little bit of white skin. I have
often been eye witness of those marvelous birth events.
They can be seen within Baker's book «Beyträge zum Gebrauch
des Mikr. p. 418.Tab.12.f.27. ... »
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