Argiope, I repeat, rushed at once out upon the web, seized the fly in her jaws and ran back to the hub with it, where she appeared to wet it all over, squeeze it into a ball and then proceed to feed upon it, holding and manipulating it skillfully all the time in her jaws. Evidently Argiope was very hungry, for as you will see, this is not her usual way of taking care of her prey. "Now, Mary, what was it you asked?" "Oh, just how the spider can run around so fast on the web without sticking to it and getting caught or tearing it all to pieces." "Ah,--ah, yes. Well, Mary, I don't know! that is, exactly; or, well not even very close to exactly. But she does it, you see." "Yes, I see," said Mary, demurely, and--can it be that Mary is slightly winking one eye? I do hope not. "Of course you know, Mary, that the web is made of two kinds of silk or rather two kinds of lines? Oh, you didn't know?" Mary has shaken her head. "Well it is," I continue, with my usual manner of teacher-who-knows somewhat restored again. "The foundation lines, the radii and a first set of circles are all made of lines without any sticky stuff on them. As you see"--and I touch my pencil confidently to a radius, with the manner of a parlor magician. "Then the spider, on this foundation, spins in another long spiral, the present circles of the web, which is liberally supplied with tiny, shining droplets of viscid silk that never dries, but stays moist and very sticky all the time. This is the true catching part of the web." "We surely must watch her spin a web sometime," breaks in eager Mary. "We certainly must," say I, and continue. "Now perhaps when Argiope runs out on the web from her watching-place at the hub, she only puts her long delicate feet on the unsticky radii. Or perhaps her feet are made in some peculiar way so that they do not stick to the circles. As a matter of fact, a spider's foot is remarkably fashioned, with curious toothed claws, and hosts of odd hairs, some knobbed, some curved and hook-like, and some forming dense little brushes. But after all, Mary, the truth is, I don't know really how it is that spiders can run about over their webs without getting stuck to them." After my long discursus about web-making and spider's feet, it seemed time to give Argiope another fly. Indeed her bright little black eyes seemed to Mary to be shining with eagerness for more fly, although she still had the remains of the first one in her jaws--gracious, Argiope's jaws, please, not Mary's!