§ 399. Children discharged from state institutions. The commissioner of social services shall co-operate with the state institutions for delinquent, mentally disabled and physically handicapped children to ascertain the conditions of the home and the character and habits of the parents of a child before his discharge from a state institution, and make recommendations as to the advisability of returning said child to his home. In case the commissioner of social services shall deem it unwise to have any such child returned to his former home, such state institution may, with the consent of the commissioner, place such child into the care of said commissioner of social services.