A round character, or a dynamic character develops and changes as the conflict progresses, whereas a flat character, or static character, remains exactly the same throughout the entire story.
In the short story, "A Shocking Accident," Jerome has a coming of age experience through the "shocking" news of his father's death. A reader might expect that the shocking news of the father's tragic death might change Jerome, but outwardly, Jerome changes very little from the news. Mr. Wordsworth seems to think that the boy is completely unfazed by the news. Inwardly, however, Jerome internalizes the incident; previously he had imagined his father to be some sort of danger-seeking spy or gun-runner. The pig-death negates Jeromes' previous glamorous image of his father. Now he must focus on ways to tell of his father's death to make it seem as non-humorous as possible. Jerome begins to change at the end of the short story as he realizes his own impending fatherhood--"his love for the dead man increased; he realized what affection had gone into the picture-postcards. He felt a longing to protect his memory" (Greene). Jerome's struggle with the awkward nature of his father's death and his newly awakened love for the man makes him more of a round character in the text.
An example of a flat character in the story is Jerome's aunt, "who had no sense of humor" (Greene). She does not change or evolve in any way during the story. She relishes the telling of Jerome's father's sad demise, mournfully pointing to the decorative picture of him to embellish her tale.