Section 4
SEC. 4. It shall be the duty of the collector of customs of the port from which any such animals are shipped, to refuse clearance to any vessel carrying any of the animals aforesaid, which are not provided with sufficient forage and fresh water for compliance with the requirements of section one; and it shall be the duty of the collector of the port at which such animals are disembarked to ascertain whether the provisions of this Act have been complied with, and if they have not, to cause prosecutions at once to be instituted by the promoter fiscal for the enforcement of the penalties herein provided. In ports in which there is no collector of customs, the duties above provided shall be performed by the inspector of customs for such port.