iece of work. Wrong: the rays are equidistant
and form a beautifully-regular orb. Their number is a characteristic
mark of the different species. The Angular Epeira places 21 in her web,
the Banded Epeira 32, the Silky Epeira 42. These numbers are not
absolutely fixed; but the variation is very slight.

Now which of us would undertake, off-hand, without much preliminary
experiment and without measuring-instruments, to divide a circle into a
given quantity of sectors of equal width? The Epeirae, though weighted
with a wallet and tottering on threads shaken by the wind, effect the
delicate division without stopping to think. They achieve it by a method
which seems mad according to our notions of geometry. Out of disorder
they evolve order.

We must not, however, give them more than their due. The angles are only
approximately equal; they satisfy the demands of the eye, but cannot
stand the test of strict measurement. Mathematical precision would be
superfluous here. No matter, we are amazed at the result obtained. How
does the Epeira come to succeed with her difficult problem, so strangely
managed? I am still asking myself the question.

The laying of the radii is finished. The Spider takes her place in the
centre, on the little cushion formed of the inaugural signpost and the
bits of thread left over. Stationed on this support, she slowly turns
round and round. She is engaged on a delicate piece of work. With an
extremely thin thread, she describes from spoke to spoke, starting from
the centre, a spiral line with very close coils. The central space thus
worked attains, in the adults' webs, the dimensions of the palm of one's
hand; in the younger Spiders' webs, it is much smaller, but it is never
absent. For reasons which I will explain in the course of this study, I
shall call it, in future, the 'resting-floor.'

The thread now becomes thicker. The first could hardly be seen; the
second is plainly visible. The Spider shifts her position with great
slanting strides, turns a few times, moving farther and farther from the
centre, fixes her line each time to the spoke which she crosses and at
last comes to a stop at the lower edge of the frame. She has described a
spiral with coils of rapidly-increasing width. The average distance
between the coils, even in the structures of the young Epeirae, is one
centimetre. {29}

Let us not be misled by the word 'spiral,' which conveys the notion of a
curved l