Allie Caulfield is Holden's younger brother, and he died of leukemia before he had the chance to grow up. Allie remains a very important figure in Holden's life and symbolizes innocence. When Allie died, Holden was so upset that he broke all the windows in his family's garage and ended up breaking his hand. He knew it was a stupid thing to do, but he did not care because Allie was so important to him.
"My hand still hurts me once in a while, when it rains and all, and I can't make a real fist any more not a tight one, I mean but outside of that I don't care much."
The significance of the above quote is that Allie still affects him. His hand might hurt in the rain because of his reaction after Allie's death, but Holden himself hurts because Allie was such a good person. Allie was intelligent, but innocent as well, and this is what Holden strives to be. Allie adds to Holden's depression because he was entirely good in Holden's mind. He was smart, funny, patient and creative, and Allie was not the only one whose...