What is Adoption And Legitimation?

Legal Definition
Adoption, properly speaking, refers only to persons who are strangers in blood, and is not synonymous with "legitimation," which refers to persons of the same blood. Where one acknowledges his illegitimate child and takes it into his family and treats it as if it were legitimate, it is not properly an "adoption" but a "legitimation." Blythe v. Ayres, 96 Cal. 532, 31 Pac. 915, 19 In R. A. 40. To accept an alien as a citizen or member of a community or state and invest him with corresponding rights and privileges, either (in general and untechnical parlance) by naturalisation, or by an act equivalent to naturalization, as where a white man is "adopted" by an Indian tribe. Hampton v. Mays, 4 Ind. T. 503, 69 S. W. 1115.
-- Black's Law Dictionary