Research on schistosomiasis has received a large amount of support during the past two decades. The result has been an outpouring of literature from all endemic areas as well as from research laboratories. Until the appearance of this monograph by Jordan and Webbe, the obvious need for a synthesis had been only partly met by the publication of several symposia. Symposia never cover a subject adequately, partly because they represent specialists talking to each other, and partly because the contributions are always of uneven quality, with a high proportion of repetitive “pot boilers.” The book by two experienced field research men is thus timely and needed. The nine chapters fall naturally into three groups. The introductory group of three chapters describe the parasites and their geographic distribution, the snails which serve as intermediate hosts, and the life cycle of the parasites. “Life cycle” in this chapter largely concerns the free-living stages and the development of the parasite in the snail.