In case of the commitment or admission of a poor person or a member of his family, through the agency of the director of welfare under the supervision of the county welfare board, to an almshouse, welfare-house or other institution or family, the director shall file a copy of the record provided for in section 44:4-50 of this title, or a record of the admission or commitment, with the commissioner at his office at Trenton, and in case of an infant a copy thereof shall be within the same time filed with the state board of children's guardians at its office. Such filing within the time limited may be by registered mail.
N.J.S. § 44:4-51