A story, read of long ago and well remembered, for which I cannot now provide citation and must tell from memory:
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Alexandre Dumas (the junior, "Dumas fils'), 1824–95, in conversation:
"Gentleman": Do I understand that you are an octoroon, sir?
Dumas: Yes
Gentleman: And thus that your father was a quadroon?
Dumas: Yes.
Gentleman: And his father a mulatto?
Dumas: Yes.
Gentleman: And his mother was?
Dumas: A negress, sir.
Gentleman: Then what was her father, sir?
Dumas: An ape, sir!!! My ancestry begans where yours has ended!
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How sad to realize that the words octoroon and quadroon were once so commonly understood that this story could be related in ordinary conversation.