She is walking then upon her network; and I do not find
that she suffers the least inconvenience. The lime-threads are not even
lifted by the movements of her legs.

In my boyhood, when a troop of us would go, on Thursdays, {31} to try and
catch a Goldfinch in the hemp-fields, we used, before covering the twigs
with glue, to grease our fingers with a few drops of oil, lest we should
get them caught in the sticky matter. Does the Epeira know the secret of
fatty substances? Let us try.

I rub my exploring straw with slightly oiled paper. When applied to the
spiral thread of the web, it now no longer sticks to it. The principle
is discovered. I pull out the leg of a live Epeira. Brought just as it
is into contact with the lime-threads, it does not stick to them any more
than to the neutral cords, whether spokes or parts of the framework. We
were entitled to expect this, judging by the Spider's general immunity.

But here is something that wholly alters the result. I put the leg to
soak for a quarter of an hour in disulphide of carbon, the best solvent
of fatty matters. I wash it carefully with a brush dipped in the same
fluid. When this washing is finished, the leg sticks to the
snaring-thread quite easily and adheres to it just as well as anything
else would, the unoiled straw, for instance.

Did I guess aright when I judged that it was a fatty substance that
preserved the Epeira from the snares of her sticky Catherine-wheel? The
action of the carbon disulphide seems to say yes. Besides, there is no
reason why a substance of this kind, which plays so frequent a part in
animal economy, should not coat the Spider very slightly by the mere act
of perspiration. We used to rub our fingers with a little oil before
handling the twigs in which the Goldfinch was to be caught; even so the
Epeira varnishes herself with a special sweat, to operate on any part of
her web without fear of the lime-threads.

However, an unduly protracted stay on the sticky threads would have its
drawbacks. In the long run, continual contact with those threads might
produce a certain adhesion and inconvenience the Spider, who must
preserve all her agility in order to rush upon the prey before it can
release itself. For this reason, gummy threads are never used in
building the post of interminable waiting.

It is only on her resting-floor that the Epeira sits, motionless and with
her eight legs outspread, ready to mark the least quive