Erratum
In Gina Kolata's article "Avoiding the schistosome's tricks" (Research News, 18 Jan., p. 285), Schistosoma mansoni and S. japonicum were inadvertently interchanged in the first full paragraph of the first column on page 286. Schistosoma japonicum lives in the mesenteric veins of the upper (small) intestine, and S. mansoni lives in the mesenteric veins of the lower (large) intestine.