As the water brought by canal is not sufficient to irrigate the entire cane acreage, the government has allowed the factories to install a number of large pumping plants by which water is raised from rivers. In such cases, whenever the factories have pumped water enough for their own requirements, they are generally willing to operate the pump free of cost to supply water to the native farmer. In the principalities or semi-independent states of Java, where the native princes have made grants of land to their nobles as appanage, another rental system prevails. Both princes and nobles lease large tracts of land for long periods to European agriculturists, and such leases include not only the fertile portion with the irrigation facilities and the water, but the rocky, barren spaces as well. Here the tenant has to make the most of the possibilities of the property and determine what part of it is best suited for cane culture and what part for other purposes. Besides the two plans of tenure just described, certain lands are held under absolute title or perpetual lease. Over a hundred years ago large tracts were sold outright at times, the title carrying all the seignioral rights, and consequently the owners are free to plant and irrigate without restriction. In later years European farmers were no longer permitted to purchase, but much jungle land was leased for seventy-five-year periods. Such leases were made for the most part in mountainous or sparsely settled territory, and as sugar culture thrives best in the low plains where labor is plentiful, sugar has not been benefited as much by the long-term leases as have tea and cinchona bark. Still there are sugar plantations that hold land under perpetual lease with unrestricted rights and water for irrigation. Plantations situated in the thickly populated lowlands have no trouble in securing labor, but it is another matter in districts that have been newly opened up or on perpetual-lease holdings where the population is small. In the last two cases labor must be brought in from other districts, and sometimes there is difficulty in doing this, especially during the rice harvest or when large public works are under construction. However, such conditions are unusual, and, as compared with other sugar-producing countries, Java is in a peculiarly fortunate position with respect to a steady supply of good labor at low cost. All of the arduous work is done by men, but women cut cane tops, plant seed and do watering and weeding, while children are employed in destroying insects and other light work.