Minnie's good friend Charles names his mealworm Minnie. So why doesn't he invite her to the party at his house this coming Saturday? <P> Hopeful at first, Minnie, by week's end, is a wreck. "No invitation, no party, no nothing," she moans, feeling as everyone feels at one time or another: unhappily left out. <P> Diana Cain Bluthenthal knows how to be a comfort -- to Minnie or anybody -- with a story and pictures that are funny as well as true to life. <P> Minnie, by week's end, is a wreck. "No invitation, no party, no nothing," she moans, feeling as everyone feels at one time or another: unhappily left out.