Dairy farmer Robert Howe was on the fence about selling his milk to another company. But that decision became much easier - a "yes" - when he learned that his sole buyer, the Horizon Organic milk company, had been bought by Dean Foods. Dean, the nation's largest milk producer, purchased Horizon, the nation's largest organic-milk producer, for $216 million. The acquisition is the latest example of the evolution of the organic-food industry. The Christian Science Monitor