In the short story, "Through the Tunnel," what do the boys represent?
The older boys, to Jerry, seem like "men," and they represent his desire to grow up. "To be with them, of them, was a craving that filled his whole body." They swim and dive so freely and confidently in the "wild bay." They need no supervision, unlike Jerry, who only just got his mother's permission to leave her for a few hours. He wants to be accepted by them because, to be accepted would mean that he is like them: that he, too, is almost a man. "He felt he was accepted" as they dived off the promontory, and so he was happy.
However, once they begin to swim through a tunnel in the rock, Jerry can no longer remain with them. They are capable of doing something that he cannot do, going somewhere he cannot follow, and so he desperately tries to get their attention. "[I]n a panic of failure," he clowned around "splashing and kicking in the water like a foolish dog," and "They swam back to the shore without a look at him." They know that he is not like them; they can tell that he is younger and foreign. And when he begins to act so childishly, they leave him without a second thought. Their rejection feels like a confirmation to Jerry that he is not the same as them, and so he "crie[s] himself out."