The account of the discussion in this and the two following chapters is not now found in the Latin Version of the “Disputation,” but is regarded by Dr. Routh as having been derived by Cyril from some different copies of the Greek.  The last paragraph of § 29, “These mysteries, &c.,” is evidently a caution addressed to the hearers by Cyril himself (Routh, Rell. Sac. V. 199).