Here's a breakdown of the ending and its possible meanings:
* The Ape's Demise: Yank, after being ostracized by both the "higher" and "lower" classes, finds himself utterly alone. His journey starts with a desire to connect, but he ends up rejecting the very thing he craved. He throws himself into the furnace, symbolizing his self-destruction and the impossibility of finding a place within the established social order.
* The Absence of Meaning: The final stage direction, "He sinks to his knees, his head bowed, and, looking down at his hands, whispers, 'I'm an ape...I'm an ape...' and so remains," suggests a final acceptance of his ostracized identity. However, this acceptance is devoid of hope or dignity. It signifies a tragic defeat, highlighting the powerlessness of the individual against the forces of society.
* The Irony of Belonging: Yank's final act, choosing to be consumed by the furnace, can be seen as a desperate attempt to belong, albeit in a destructive way. He seeks connection with the "things" he feels more kinship with—the machines, the heat, the raw power—which ultimately represents the very thing he rejects in the human world.
* The Critique of Capitalism: O'Neill's play is deeply critical of the capitalist system, which dehumanizes and exploits the working class. Yank represents the marginalized, the forgotten, and the expendable in a society obsessed with material wealth and social status. His downfall underscores the dangers of such a system.
In conclusion, the ending of *The Hairy Ape* offers a bleak and unsettling vision of human alienation and the struggle for belonging in a world defined by class and power. It leaves the reader with a lingering sense of tragedy and a deep questioning of societal structures and the consequences of being an outsider.