A single line which finds anchorage in this way is sufficient for the purposes of the spider. It has only to cross over to the new object, attach a thread to some other point of it, and carry it back across the bridge to fix it at a convenient spot on the surface which formed the base of its operations. Between two such bridge-lines the circular snare is constructed in a manner to be presently described. Sometimes the tentative threads emitted by the spider travel far before finding attachment. In the case of the English _Epeira diademata_ the writer has measured bridge-lines of eleven feet in length; and with the great Orb-weavers of tropical countries they frequently span streams several yards in width. Two stout bridge-lines thus constructed will form the upper and lower boundaries of the net. The lateral limits are easily formed by cross lines between them at a convenient distance apart. The spider chooses a point, say, on the upper bridge-line, fixes its thread there, and carries it round to the lower line, where it is hauled taut and firmly attached. Two such cross lines give, with the bridge-lines, an irregular four-sided figure within which to stretch the snare, and now the work is perfectly straightforward, and can proceed without interruption. Attention is first paid to the radii of the circular web. The first radii are formed by drawing cross lines within the framework in the same manner as before, but the spider carefully attaches these where they intersect by a small flossy mass of silk, and this central point or hub becomes the basis of its subsequent operations. It is a simple matter to add new radial lines by walking from the centre along one of those already formed and fixing the thread to some new point of the circumference. They are not laid down in any invariable order, but with a kind of alternation which has the general effect of keeping the strain on every side fairly equal. Almost every time the spider reaches the centre it slowly revolves, uniting the radii afresh at their point of junction, and increasing the strength and complexity of the hub. It also occasionally digresses so far as to stretch the whole structure by bracing the framework at additional points, so that it loses its four-sided form and becomes polygonal. We have now a number of spokes connecting a central hub with an irregular circumference.