There is an old expression that says that one must keep one's nose to the grindstone if one wants to succeed. This means that one must work hard and continuously, never letting up for long. A grindstone is a flat, circular stone that is mounted on an axle and turned by a foot pedal. It is used to file and sharpen tools.

At the beginning of James Hurst's story "The Scarlet Ibis," the narrator, speaking long after the events of the story, tells us that a grindstone now stands on the site of the bleeding tree. When he hears the grindstone at work, he remembers Doodle.

The grindstone is a symbol of Doodle's efforts to please his brother. The little boy works so hard, trying to build his strength, trying to be like a "normal" child, trying to earn his brother's praise and esteem. He learns to walk after weeks of extensive efforts. He tries hard to run and swim and row a boat and climb trees and fight, everything his brother wants him to do. Indeed, Doodle keeps his nose to the grindstone day in, day out, working hard and continuously to make his brother happy.

In a way, the grindstone can also symbolize the narrator himself. His constant demands on Doodle wear the little boy down. They scrape away at him, grinding at him, wearing him out. Ironically, however, the narrator does not really sharpen his brother through this process. He makes him weaker over time, for although he doesn't realize it, all the activities overtax Doodle's weak heart. Instead of sharpening his brother into the fine point he hopes to make, he diminishes him into metaphorical dust, and Doodle finally wears out completely, dying at the end of the story.