Instructions: Try organizing the material in the
following passage. You may use a map or flowchart format.
The cattle tick is a small, flat-bodied, blood-sucking arachnid
with a curious life history. It emerges from the egg not yet
fully developed, lacking a pair of legs and sex organs. In this
state it is still capable of attacking cold-blooded animals such
as frogs and lizards, which it does. After shedding its skin
several times, it acquires its missing organs, mates, and is then
prepared to attack warm-blooded animals.
The eyeless female is directed to the tip of a twig on a bush by
her photosensitive skin, and there she stays through darkness and
light, through fair weather and foul, waiting for the moment that
will fulfill her existence. In the Zoological Institute at
Rostock, prior to World War I, ticks were kept on the end of
twigs, waiting for this moment for a period of eighteen years.
The metabolism of the creature is sluggish to the point of being
suspended entirely. The sperm she received in the act of mating
remains bundled into capsules where it, too, waits in suspension
until mammalian blood reaches the stomach of the tick, at which
time the capsules break, the sperm are released, and they
fertilize the eggs which have been reposing in the ovary, also
waiting a kind of time suspension.
The signal for which the tick waits is the scent of butyric acid,
a substance present in the sweat of all mammals. This is the only
experience that will trigger time into existence for the tick.
The tick represents, in the conduct of its life, a kind of
apotheosis of subjective time perception. For a period as long as
eighteen years nothing happens. The period passes as a single
moment; but at any moment within this span of literally senseless
existence, when the animal becomes aware of the scent of butyric
acid it is trust into a perception of time, and other signals are
The animal then hurls itself in the direction of the scent. The
object on which the tick lands at the end of this leap must be
warm; a delicate sense of temperature is suddenly mobilized and
so informs the creature. If the object is not warm, the tick will
drop off and re-climb its perch. If it is warm, the tick burrows
its head deeply into the skin and slowly pumps itself full of
blood. Experiments made at Rostock with membranes filled with
fluids other than blood proved that the tick lacks all sense of
taste, and once the membrane is perforated the animal will drink
any fluid, provided it is of the right temperature.
The extraordinary preparedness of this creature for that moment
of time during which it will re-enact the purpose of its life
contrasts strikingly with probability that this moment will ever
occur. There are doubtless many bushes on which ticks perch,
which are never bypassed by a mammal within range of the tick's
leap. As do most animals, the tick lives in an absurdly
unfavourable world -- at least so it would appear to the
compassionate human observer. But this world is merely the
environment of the animal. The world it perceives -- which
experimenters at Rostock call its "umwelt," its perceptual world
-- it not at all unfavourable. A period of eighteen years, as
measured objectively by the tick. During this period, it is
apparently unaware of temperature changes. Being blind, it does
not see the leaves shrivel and fall and then renew themselves on
the bush where it is affixed. Unaware of time, it is also unaware
of space. It waits, suspended in duration for its particular
moment of time, a moment distinguished by being filled with a
single, unique experience; the scent of butyric acid.
Though we consider ourselves far removed as humans from such a
lowly insect form as this, we too are both aware and unaware of
elements which comprise our environment. We are more aware than
the tick of the passage of time. We are subjectively aware of the
aging process; we know that we grow older, that time is shortened
by each passing moment. For the tick, however, this moment that
precedes it burst of volitional activity, the moment when it
scents butyric acid and it thrust into purposeful movement, is
close to the end of time for the tick. When it fills itself with
blood, it drops from its host, lays its eggs and dies.
Click here to see an example of how
the information in this paragraph could be organized.
When you are done, set your work aside, so you can't see it, and
try to reproduce it from memory, to see how well it helps you to
remember and understand the material.