Who is Dr. Hugh from Tales of Henry James: The Texts of the Stories, the Author on His Craft, Background and Criticism and what is their importance?

Dr. Hugh appears in the story, The Middle Years. He is a physician, who has recently graduated from medical school and is working as personal physician to the wealthy, obese Countess. While working for the Countess, he meets Duncombe, an author he greatly admires. Over the course of the novel, the two men develop a close relationship. Eventually, Dr. Hugh leaves the Countess' employ, giving up rights to an inheritance from her, to be with Duncombe.