Page 74 - The Miracle in the Spider

74 THE MIRACLE IN THE SPIDER

keratin is changed. By the use of the control mechanism in the valves the
diameter, resistance and elasticity of the thread can be altered while it is
being produced. Thus the thread can take on the desired physical
characteristics without the need for a change in its chemical composition.
If any greater change to the thread is desired, another gland has to come
into operation. The resulting tiny silk threads with their many features are
then set in the desired way by expert use of the rear legs.
The ratios in which the products of six different glands are mixed are
of the utmost importance. For example, when the sticky thread is being
produced, if that material which gives the sticky quality is not used in
sufficient quantities, it will lose the ability to catch insects. If it is used in
too great quantities, the usability of the web will be reduced. For the
thread to serve its purpose, the products of the other glands must
necessarily be applied at the right level.
The result of these processes being successfully completed is spider
silk, with its properties, all different from each other, and able to serve
different functions. Spider silk is so strong that Vollrath, the zoologist,
describes it in these words: "Spider silk is stronger and more elastic than
Kevlar, and Kevlar is the strongest man-made fiber." 23
And these are not the only special qualities of spider silks. Unlike
Kevlar, a kind of plastic used in the production of bullet-proof jackets
because of its strength, spider silk can be recycled and used again and
again.
The most important point here is that this most perfect product in the
world, stronger than steel and more elastic than rubber, is made in the
body of the spider. Even the largest textile factories, the most developed
weaving establishments, and chemical laboratories fully equipped with
the latest technology and researching into atoms have been unable to
manufacture anything quite like spider silk. So how did a spider plan
such an incomparable chemical make-up? After having planned it, how
did it identify the source of the raw materials necessary for production
and how did it settle on the six basic ingredients? What measuring
equipment did it use to establish the proportions between them?