The third edition of this basic textbook in parasitology has been entirely rewritten, incorporating the spectacular advances made in biological sciences within recent years. The author presents students and research workers with a broad multi-disciplined approach to the morphology, ultrastructure, speciation, life cycles, biochemistry, in vitro culture and immunology of parasites. Special attention is paid to those species used as models for teaching and research as well as the major human and animal parasites. The author introduces the basics of the subject for new students as well as bringing in more advanced topics of interest to senior students and researchers. The text is illustrated with a large number of figures, tables and up-to-date reference lists. The book will appeal to all students with an interest in parasitology as well as being of interest to research workers in the field.