One day, an ape escaped from the Bronx Zoo. They searched for him everywhere in every borough. They announced his disappearance on the radio and television as well as in the newspapers, but no one reported seeing the ape.

At last, the ape was discovered in the New York Public Library. Officials of the zoo and the animal handlers were summoned to the library. They found the ape sitting at a desk in the reading room with two books spread out in front of him. The ape was reading with great concentration. One book was the Bible; the other was a book written by Darwin.

The zookeepers asked the ape what he was doing.

The ape replied, "I'm trying to figure out whether I am my brother's keeper or my keeper's brother."