As it is the essential function of a railway to convey the produce of the area it serves to the exporting port, the problem of the relations between the administration of railways and the administration of ports is of primary importance. The chief ports served by different companies, such as Rosario and Buenos Aires, may maintain their independence, but a secondary port will be at the mercy of the single line which conveys goods to it. In such circumstances the ports have become, in many cases, mere dependencies of the railways. The port of Colastine belongs to the railways of the Santa Fe province. The port of Bahia Blanca consists of a number of distinct ports constructed by the different railway companies, and run by them. Each of them ships the goods which it brings. The port Ingeniero White, which belongs to the Southern Company, was constructed in 1885, immediately after the opening of the line from Buenos Aires to Bahia Blanca. Puerto Galvan belongs to the Pacific Company. Puerto Belgrano is the port of the line from Rosario to Bahia Blanca. At Buenos Aires the Southern Railway Company has acquired control of the Buenos Aires Southern Dock Company. At La Plata it manages the docks. The spread of agricultural colonization was at first hampered by the cost of freightage which cereals could bear over an area with a radius of about 200 miles from the ports. That is the figure given by Girola in the _Investigacion Agricola_ of 1904. The period 1895-1905 saw the birth of a series of plans for making canals in the Pampean region for the purpose of transporting grain in the area which the railway did not seem able to serve economically. Not one of them was carried out, but the railways quickly enlarged their sphere of influence in the interior. There is, however, a reminiscence of this pause in colonization in what Argentinians call "the parabolic tariffs." The Argentine railways practically, apart from cases of competition with rival lines, use proportional tariffs up to a distance of 218 miles, and degressive tariffs beyond that limit. In this way the railways have helped in the conquest of the west. Degressive tariffs have certainly played a part in the spread of colonization during the years antecedent to 1912. They have helped to mask the inferiority of the new land to the better land in the east.[115] [115] J. Lopez Manan, _El actual problema agrario_ (Buenos Aires, 1912, Ministerio de agricultura, Direccion General de agricultura y defensa agricola).