"Flowers for Algernon" By Daniel Keys, published in Fantasy and Science Fiction.
Copyright 1959 by Mercury Press.

April 6

I beat Algernon! I dint even know I beat him until Burt the tester told me. Then the second time I lost because I got so exited I fell off the chair before I finished. But after that I beat him 8 more times. I must be getting smart to beat a smart mouse like Algernon. But I dont feel smarter.
I wanted to race Algernon some more but Burt said thats enough for one day. They let me hold him for a minit. Hes not so bad. Hes soft like a ball of cotton. He blinks and when he opens his eyes their black and pink on the eges.
I said can I feed him because I felt bad to beat him and I wanted to be nice and make friends. Burt said no Algernon is a very specshul mouse with an operashun like mine, and he was the first of all the animals to stay smart so long. He told me Algernon is so smart that every day he has to solve a test to get his food. Its a thing like a lock on a door that changes every time Algernon goes in to eat so he has to lern something new to get his food. That made me sad because if he couldnt lern he woud be hungry.
I don't think its right to make you pass a test to eat. How woud Dr Nemur like it to have to pass a test every time he wants to eat. I think Ill be friends with Algernon.