of this title. The liability of the individual banks in each group must be limited to such proportion of the total amount advanced to such group as the deposit liability of the respective banks bears to the aggregate deposit liability of all banks in such group, but such advances may be made to a lesser number of such member banks if the aggregate amount of their deposit liability constitutes at least 10 per centum of the entire deposit liability of the member banks within such district. Such banks shall be authorized to distribute the proceeds of such loans to such of their number and in such amount as they may agree upon, but before so doing they shall require such recipient banks to deposit with a suitable trustee, representing the entire group, their individual notes made in favor of the group protected by such collateral security as may be agreed upon. Any Federal reserve bank making such advance shall charge interest or discount thereon at a rate not less than 1 per centum above its discount rate in effect at the time of making such advance. No such note upon which advances are made by a Federal reserve bank under this section shall be eligible under