COGNATION, civil law. Signifies generally the kindred which exists between two persons who are united by ties of blood or family, or both. 2. Cognation is of three kinds: natural, civil, or mixed. Natural cognation is that which is alone formed by ties of blood; such is the kindred of those who owe their origin to an illicit connexion, either in relation to their ascendants or collaterals. 3. Civil cognation is that which proceeds alone from the ties of families as the kindred between the adopted father and the adopted child. 4. Mixed cognation is that which unites at the same time the ties of blood and family, as that which exists between brothers, the issue of the same lawful marriage. 6; Dig. 38, 10.