Sura 33:4 says that Allah has not put two hearts into any man. Yet duplication of the heart has been admitted, albeit with reluctance by Geoffrey-Saint-Hilaire and celebrated anatomists including Littre, Meckel, Colomb, Panum, Behr, Paullini, Rhodius, Winslow and Zacutus Lusitanus G. M. (Source : Gould, W. L. Pyle (Julian Press, 1896) Anomalies and Curiosities of Medicine p. 296)