Upon receipt of the invoice specified in section 158.07 a county auditor shall issue a warrant on the poor fund for the amount due, except that in any county now or hereafter caring for the poor under a county poor commission, the notice shall be given to the county poor commission, which shall issue its warrant on the poor fund of the county for the amount due. The warrant shall be delivered to the county treasurer, who shall, if funds are available, issue a check payable to the University of Minnesota for the amount of the warrant. If no funds are available in the poor fund for the payment of the warrant, it shall be registered. The check or registered warrant shall be mailed to the University of Minnesota. All payments hereunder are appropriated to the University of Minnesota.