PARIS — When it comes to mixing unlikely elements into a charming, frothy, wild or utterly arresting pastiche, few can beat John Galliano. And he illustrated just why with the extraordinary spring couture collection he showed for Christian Dior on Monday, which was inspired by a November visit to Russia. The combination this time: pre-Revolutionary St. Petersburg with touches of Mongolia, China and the circus. Here, his colorful, richly embellished coat. For more on the season, see pages 4 to 9.