Do the horses on the carousel mean anything?

If the carousel itself is meant to symbolize in its revolutions the years of a person's childhood, it is appropriate for Phoebe to keep riding on it. Holden looks back on it with fondness, but when Phoebe presses him to get on and ride with her again, he refuses, telling her that he'd rather watch her. Holden has come to realize that his childhood is behind him, and though it is painful to leave the ease of childhood behind, he really has no choice. Holden has reached his adult height, has gray in his hair, and will, despite his efforts to postpone it, graduate from high school soon. Like most adults, he has had a broken romance, and he has suffered a horrible loss with Allie's death. By stepping off the carousel and watching and enjoying his little sister's enjoyment of it, Holden achieves the bittersweet understanding that his childhood has ended.