Share this credible answer with others. Simply paste this code into your blog or Web page:
They crawl about over a trail of mucus that is secreted by specialized epidermal cells; the smaller forms move about by means of cilia on their ventral, or lower, surface, and larger species utilize muscular contractions as well.
|
Answer verified with
|
HighBeam gives you access to newspaper, magazine, and trade journal articles plus press releases, facts, information, and biographies from thousands of sources.