It is simply marvellous.
The Epeira hunts not with springs, but with lime-snares.

And such lime-snares! Everything is caught in them, down to the dandelion-plume that barely brushes against them.

Nevertheless, the Epeira, who is in constant touch with her web, is not caught in them.

Why?
Because the Spider has contrived for herself, in the middle of her trap, a floor in whose construction the sticky spiral thread plays no part.

There is here, covering a space which, in the larger webs, is about equal to the palm of one's hand, a neutral fabric in which the exploring straw finds no adhesiveness anywhere.
Here, on this central resting-floor, and here only, the Epeira takes her stand, waiting whole days for the arrival of the game.