Mystery solved

According to Juren Ziesmann, who has dedicated an entire webpage to the subject, Cobwebs are actually made by spiders. Evidently the difference between a spider web and a cobweb is that a cobweb has been vacated by the spider. To get more information on the subject, (if you're still on the edge of your seat) go to: http://www.madsci.org/posts/archives/may97/859695397.Zo.r.html and read all about it.