Dog Growling at Baby

Someone recently wrote to me for advice on a difficult situation developing between her dog and her baby. When such a problem arises, I think you need to teach the baby that he may NOT sit on the dog, pull ears, bother the dog when it's lying down, hit it with toys, and so on. You can't do this with punishment, babies can't learn that way; but you can do it. The dog needs to learn to get up and leave if bothered; but the baby needs to experience being removed, gently but firmly, from the dog, long BEFORE the dog has become irritated to the point of growling.