No assignment or transfer of any such bonds by the Treasurer shall be deemed valid or of binding force and effect unless countersigned by the Comptroller of the Currency. It shall be the duty of the Comptroller of the Currency to keep in his office a book in which shall be entered the name of every association from whose accounts such transfer of bonds is made by the Treasurer, and the name of the party to whom such transfer is made; and the par value of the bonds so transferred shall be entered therein; and it shall be the duty of the Comptroller, immediately upon countersigning and entering the same, to advise by mail the association from whose account such transfer was made of the kind and numerical designation of the bonds and the amount thereof so transferred.