Art. 54 BV; legitimation of a child born out of wedlock by subsequent marriage presupposes the marriage of the child's natural parents. Legitimation consists in the child acquiring the status of a legitimate child vis-à-vis both parents, including entry into the father's family, name, and citizenship. Where the husband expressly denies paternity, the child is not legitimized by his marriage to the mother; at most, adoption may be considered, but its admissibility and conditions are governed exclusively by cantonal law (consid. 1).