All then that is needed is a thread issuing from this central point to convey to a distance the news of a prey struggling in some part or other of the net.

The slanting cord, extending outside the plane of the web, is more than a foot-bridge: it is, above all, a signalling-apparatus, a telegraph-wire.
Let us try experiment.

I place a Locust on the network.

Caught in the sticky toils, he plunges about.

Forthwith, the Spider issues impetuously from her hut, comes down the foot-bridge, makes a rush for the Locust, wraps him up and operates on him according to rule.