ABSTRACT
The history of malaria is one of slow diminution in many tropical countries, and of almost complete disappearance from countries with temperate climates, in which it formerly prevailed. Malaria until recent years has always been regarded as a soil-generated disease, especially of soil the energies of which are not expended in growth and sustenance of healthy vegetation. MacCulloch in 1872 traced malaria's influence in causing race degeneration in various parts of the world, and W. H. S. Jones in 1909 concluded that malaria played a large part in bringing about the decadence of Greece. Manson had forecasted that different species of malarial parasite may require different kinds of mosquito as their alternative hosts, and this was verified by Ross's work and that of Grassi and others. In view of the life-history of the malarial plasmodium evidently many circumstances are concerned in the completion of its life-cycle, and therefore many measures may succeed in thwarting its personal and family history.
