Endless Fascination with Chitin

The exoskeleton of spiders (and insects) is made of chitin, a polysaccharide not unlike the cellulose that composes the structural support in plant cell walls, like those in this salvia leaf. We know plants aren't fungi because the cell walls of fungi are made of chitin. We know fungi aren't spiders because they don't crawl around, eat flies or spin webs. We know this is a spider molt because it has eight leg-skins and it looks nothing like a mushroom. The spider that shed this exoskeleton has crawled away now; this we know because we can't see it. Everything else we must guess at or surmise.