Helminths impinge upon so many aspects of human welfare and in such diverse fashion that they must be studied from several vantage points. The relatively young science of parasitology (in which, perhaps, helminths feel most at home) is already, as Huff (1956) has pointed out, a conglomerate—involving such disciplines as systematics, natural history, physiology, biochemistry, immunology, treatment, and control. I venture to suggest that the principal viewpoints are: zoological, medical, and economic.
It is the economic aspect of helminth infection with which I propose to deal here. An apostle of economic parasitology must draw freely from the teachings of the more fully developed zoological and medical branches. As an expression of gratitude for their contributions, it is possible that economic parasitology can offer a suggestion or two in return.
Huff challenges us to name any general principles developed by the science of parasitology comparable to Mendel's law in genetics or the law of mass action in chemistry.