What part is the irony in Tarzan of apes?

In Edgar Rice Burroughs' Tarzan of the Apes, the irony lies in the fact that Tarzan, who was raised by apes in the African jungle, is the true heir to an English lordship. He possesses noble blood and a rightful claim to a title and fortune, yet he has grown up in a completely different world, far from the society and civilisation of his ancestors. This contrast between his noble heritage and his upbringing among wild animals creates an ironic situation where a man of high birth and privilege leads a primitive life, unaware of his true identity and the life that could have been his.