Parasites prt:scIU a continual and unacceptable threat to the well-being of millions of people in tbe tropics and subtropics and to domesticated

animals in all parts of the world and tbe cost of harbouring parasites in terms of human misery and economic loss is incalculable. Parasitology is

the study of parasites .and their interactions with rneir hosts. The science of parasitology has a long history and has its fOOtS in zoology,