741.21 Incestuous marriages prohibited.—A man may not marry any woman to whom he is related by lineal consanguinity, nor his sister, nor his aunt, nor his niece. A woman may not marry any man to whom she is related by lineal consanguinity, nor her brother, nor her uncle, nor her nephew.History.—RS 2602; GS 3525; RGS 5415; CGL 7558.