After decades with the Muscular Dystrophy Assn., Jerry Lewis is dropped as the telethon's host and the group's national chairman. Fellow comedians decry the mysterious ouster.For the first time in 45 years, Jerry Lewis will not be pleading for donations in front of a camera Labor Day weekend after he was abruptly dismissed as the host of the Muscular Dystrophy Assn.'s telethon, an event that drew attention to the childhood disease and in its heyday was an annual television highlight.