In Salinger's The Catcher in the Rye, what happened to the composition Holden wrote for Stradlater?

It is ironic that Holden Caulfield is flunking out of Pencey Prep and yet that he is writing a composition for his roommate Stradlater, who is a star athlete and is regarded as a good student. Holden must have written his composition about the baseball glove in longhand, because we learn later that another boy has borrowed Holden's typewriter and buys it from him just before Holden leaves for New York.

Stradlater is irate when...

It is ironic that Holden Caulfield is flunking out of Pencey Prep and yet that he is writing a composition for his roommate Stradlater, who is a star athlete and is regarded as a good student. Holden must have written his composition about the baseball glove in longhand, because we learn later that another boy has borrowed Holden's typewriter and buys it from him just before Holden leaves for New York.

Stradlater is irate when he reads the composition and finally understands that it is about a baseball glove.

"All of a sudden, he said, "For Chrissake, Holden. This is about a goddamn baseball glove."

Stradlater is afraid that if Holden writes a composition for him it might look "too good." This composition about a baseball glove with quotations written all over it might seem to fall into that category. 

"So what?" I said. Cold as hell.

"Wuddaya mean so what?" I told you it had to be about a goddam room or a house or something."

We can see what sort of a composition Stradlater would turn out if he had to write it himself.

The argument escalates until Holden says:

"All right, give it back to me, then." I went over and pulled it right out of his goddam hand. Then I tore it up....I just threw the pieces in the wastebasket.

As Stradlater says, Holden can't even seem to conform when he is ghostwriting a composition for another student to submit as his own work. The quarrel, which turns into a real physical fight, shows that Holden is a nonconformist who is his own worst enemy. It also shows that Holden is such a good writer that he is capable of writing a whole novel like The Catcher in the Rye. Holden is sensitive about the composition he wrote for Stradlater for nothing because it is about his younger brother Allie who died of leukemia. Stradlater did not realize what a gift Holden was giving him.