The Division of Scientific Research, as its name implies, is charged with studies of various diseases such as typhoid, malarial, typhus and yellow fevers, leprosy, tuberculosis, trachoma, pellagra, sanitation and hygiene, water supply and sewage and public health administration in states and cities in cooperation with the local authorities. This division conducts a Hygienic Laboratory at Washington and a number of field laboratories where intensive studies in these subjects are conducted. Through this division the Surgeon General of the Service enforces the laws for the regulation of the sale of viruses and serums and calls annual and special conferences of the health authorities of the several states and territories for the purpose of cooperation in the suppression of preventable diseases and the general improvement of the public health. The Division of Foreign and Insular Quarantine and Immigration is charged with the execution of the national quarantine laws, this being accomplished at fifty Federal Quarantine Stations in the United States, with additional stations at Panama, Porto Rico, the Virgin Islands, Hawaii and the Philippines. There are also medical officers under this division detailed at various Consular stations of the United States in foreign countries to assist in the prevention of the introduction of contagious or infectious diseases into the United States or its possessions. This division also conducts the physical and mental examinations of all aliens entering the territory of the United States at any of its ports. The Division of Domestic and Interstate Quarantine has charge of the enforcement of the laws for the prevention of the spread of contagious or infectious diseases from one state or territory to another. The Division of Sanitary Reports and Statistics has cognizance of the collection and publication of information relative to the diseases which may threaten the public health of the United States and foreign countries. The Division of Marine Hospitals has charge of twenty-two Marine Hospitals and about one hundred and twenty-five smaller relief stations at the different ports and cities of the country. At these stations and hospitals the sick and disabled officers and seamen of the Coast Guard and Lighthouse Services, the Mississippi River Commission, the Engineer Corps of the Army at work upon rivers and harbors works, and the registered and licensed ships of the United States merchant marine are given necessary medical and surgical treatment. This division also furnishes the medical officers for the vessels of the Coast Guard. The Division of Personnel and Accounts has charge of the record of the officers and men of the service and of the expenditures of the moneys appropriated for the service from the public funds.