An uninspired run-down, beginning with the bacteriophage, a kind of virus, and proceeding up through molds, fungi, trichini, worms, and such ectoparasites as bedbugs, lice and sea lampreys (or ""hitchhikers""). There are also examples of the ""three-cornered relationship"" of vector, host and parasite involved in malaria, yellow fever, etc., and the Goldsteins occasionally interrupt their reports on life cycles and host damage to invite speculation on, for example, how the relationships got started. But most of the questions are beside any point--""Did the cave dwellers have more parasites than modern humans? Each reader will have to draw his or her own conclusions""--and other concepts such as the advantages and disadvantages (degeneration) of being a parasite are cutely phrased (even to quoting parasites in their own defense!) and superficially treated. Of course we've all been hit with the kind of biology assignment that could keep this alive.