How does Eusebius affirm Christ's lineage to be correct in the book, The History of the Church from Christ to Constantine?

Some claim that the two genealogies of Christ in Matthew and Luke have discrepancies. However, this is false because one genealogy traces Christ's lineage by law and the other by nature. Eusebius quotes a letter from Africanus to Aristides on this matter. He showed that Mary and Joseph belonged to the same tribe in this way.