This well-known text comes through its 4th revision with minimal change in format. Except for a few deletions, the drawings remain the same as in previous editions. Some photographs have been added, others replaced, generally, but not always, with improvement.
The chapter on Protozoa shows most revision. The scheme of classification has been updated, and Entamoeba hartmanni is at last recognized as a separate species. Important new material has been added on primary amebic encephalitis (Naegleria), babesiosis, sarcocystosis, and toxoplasmosis, reflecting the advances of the last few years in our understanding of these entities. Pneumocystis is also expanded and updated, its affinities left undetermined.
Trematodes and Cestodes survive relatively intact, but with some new illustrations for echinococcus disease. In the Nematodes, Capillaria philippinensis has been added, and new photographs for Enterobius, Toxocara, and Lagocheilascaris. Ascaris and Anisakis, and cutaneous and visceral larva migrans have been refurbished, with new illustrations; the same for Dirofilaria and guinea worm.